Edgar Filing: PROGENICS PHARMACEUTICALS INC

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

______________

FORM 10-K/A

(Amendment No. 2)

(Mark One)

x	ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
	For the fiscal year ended December 31, 2012
	Or
¨	TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
	For the transition period from ___________ to ___________

Commission File No. 000-23143

______________

PROGENICS PHARMACEUTICALS, INC.

(Exact name of registrant as specified in its charter)

Delaware	13-3379479
(State or other jurisdiction of incorporation or organization)	(I.R.S. Employer Identification Number)

______________

777 Old Saw Mill River Road

Tarrytown, NY 10591

(Address of principal executive offices, including zip code)

Registrant's telephone number, including area code: (914) 789-2800

Securities registered pursuant to Section 12(b) of the Act:

Title of each class Name of each exchange on which registered

Common Stock, par value $0.0013 per share The NASDAQ Stock Market LLC

Securities registered pursuant to Section 12(g) of the Act:

None

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes o No x

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. Yes o No x

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports) and (2) has been subject to such filing requirements for the past 90 days. Yes x No ¨

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Website, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§ 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).Yesx No ¨

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein, and will not be contained, to the best of registrant's knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K. x

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer or a smaller reporting company. See definition of "large accelerated filer," "accelerated filer" and "smaller reporting company" in Rule 12b-2 of the Act:

Large Accelerated Filer ¨	Accelerated Filer x
Non-accelerated Filer ¨ (Do not check if a smaller reporting company)	Smaller Reporting Company ¨

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes o No x

The aggregate market value of the voting and non-voting stock held by non-affiliates of the Registrant on June 30, 2012, based upon the closing price of the Common Stock on The NASDAQ Stock Market LLC on that date of $9.78 per share, was $184,846,567 ⁽¹⁾.

(1)	Calculated by excluding all shares that may be deemed to be beneficially owned by executive officers, directors and five percent stockholders of the Registrant, without conceding that any such person is an "affiliate" of the Registrant for purposes of the Federal securities laws.

As of March 8, 2013, 51,131,349 shares of Common Stock, par value $.0013 per share, were outstanding.

TABLE OF CONTENTS


	Explanatory Note	1

PART I
Item 1.	Business	2
Item 1A.	Risk Factors	16

PART IV
Item 15.	Exhibits, Financial Statement Schedules	32

SIGNATURES		33
EXHIBIT INDEX		34

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EXPLANATORY NOTE

Progenics Pharmaceuticals, Inc. is filing this Amendment No. 2 on Form 10-K/A to its Annual Report on Form 10-K for the year ended December 31, 2012, as originally filed with the U.S. Securities and Exchange Commission March 15, 2013, and as amended by Amendment No. 1 on Form 10-K/A filed April 30, to amend Part I -- Items 1 and 1A to include therein certain clinical, regulatory and intellectual property information in response to comments received from the Staff of the SEC's Division of Corporation Finance. This Amendment also amends Part IV -- Item 15, which includes the Exhibit Index, to add new officer certifications in accordance with Rule 12b-15 and Rule 13a-14(a) under the U.S. Securities Exchange Act of 1934.

Substantially all material information so included in this Amendment relating to our PSMA ADC product candidate and to Relistor^®has previously been disclosed in periodic and other filings with the SEC; certain information so included relating to Azedra™ and MIP-1404, which were originally developed by our Molecular Insight subsidiary (acquired in January 2013), was not included in our March 15, 2013 original 2012 Form 10-K filing but was included in MIP SEC filings while it was a publicly traded company.

Except where necessary to provide context or avoid confusion, Progenics is not modifying, and this Amendment does not change, other disclosure presented in its 2012 Form 10-K. The Company is not modifying, and this Amendment does not change, the financial statements contained in the 2012 Form 10-K. This Amendment should therefore be read in conjunction with the March 15, 2013 original and April 30 Amendment filings and our other SEC reports and filings since that date.

This Amendment, together with Progenics' 2012 Annual Report on Form 10-K filed March 15, 2013 and Amendment No. 1 on Form 10-K/A filed April 30, constitutes its Annual Report on Form 10-K for the year ended December 31, 2012.

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PART I

Item 1. Business

Progenics Pharmaceuticals develops innovative medicines for oncology. A significant part of our research and development efforts centers on prostate specific membrane antigen (PSMA), a protein found at high levels on the surface of prostate cancer cells and also on the neovasculature of a number of other types of solid tumors. We are conducting phase 2 clinical trials of two product candidates for prostate cancer: our therapeutic candidate, PSMA ADC, a fully human monoclonal antibody-drug conjugate (ADC) directed toward PSMA and designed to deliver targeted chemotherapy to cancer cells, and MIP-1404, an imaging agent candidate with potential to alter clinical practice in treating prostate cancer in development by Molecular Insight Pharmaceuticals, a clinical-stage biotechnology company we acquired this January. Among other assets in our pipeline of targeted radiotherapy and molecular imaging compounds from the acquisition are a group of small molecule therapeutics, MIP-1095, -1555 and -1558, in preclinical study for metastatic prostate cancer and other PSMA-expressing cancers, and Azedra™, an ultra-orphan radiotherapy candidate in phase 2 study for pheochromocytoma and potential additional indications.

Progenics has developed internally and acquired from research institutions, pharmaceutical and biotechnology companies compounds and technologies which we determine to advance with other parties, including our first commercial drug, Relistor^® (methylnaltrexone bromide) subcutaneous injection for the treatment of opioid induced constipation, which we have licensed to Salix Pharmaceuticals, Inc. worldwide other than Japan, where we have licensed the subcutaneous formulation of the drug to Ono Pharmaceutical Co., Ltd. We have also recently out-licensed to MedImmune, LLC our proprietary C. difficile research program, and transferred our PRO 140 HIV viral-entry inhibitor to CytoDyn Inc. for upfront cash, milestones and royalties. We continue to consider opportunities for strategic collaborations, out-licenses and other arrangements with biopharmaceutical companies involving our proprietary research, development and clinical programs, and may in the future also in-license or acquire additional oncology compounds and/or programs.

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ONCOLOGY

Clinical product candidates	Proposed indication	Status

PSMA ADC	Treatment of prostate and other cancers	Phase 2 testing ongoing

MIP-1404	Imaging agent for prostate cancer	Phase 2 testing ongoing

	Imaging agent for prostate cancer (Japan)	In development by FUJIFILM RI Pharma

Azedra™	Treatment of pheochromocytoma (ultra-orphan) and paraganglioma	Phase 2b registrational trial under Special Protocol Assessment

	Neuroblastoma	Phase 2a testing completed

Research

Small molecule therapeutics (MIP-1095, -1555 and -1558)	Treatment of prostate cancer	Preclinical

RELISTOR^®

Marketed commercial product	Approved indication	Status

Relistor-Subcutaneous injection	Treatment of opioid induced constipation (OIC) in advanced-illness patients receiving palliative care when laxative therapy has not been sufficient	Marketed in the U.S., E.U., Canada, Australia and elsewhere; Licensed to Salix Pharmaceuticals worldwide other than Japan

Clinical product candidates	Proposed indication

Relistor-Subcutaneous injection	Treatment of OIC in patients with non-cancer pain	Complete Response Letter received on pending sNDA

Relistor-Subcutaneous injection	Treatment of OIC (Japan)	In development by Ono Pharmaceutical

Relistor-Oral	Treatment of OIC	Phase 3 testing completed

PARTNERED PROGRAMS

	Proposed indication	Status

PRO 140	Treatment of Human Immunodeficiency Virus (HIV) infection	Partnered with CytoDyn; phase 2


Anti-C. difficile monoclonal antibodies	Treatment of conditions caused by Clostridium difficile toxins	Partnered with MedImmune; phase 2

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Notes:

In this document, Relistor, a registered trademark, refers to methylnaltrexone – the active ingredient of Relistor -- as it has been and is being developed and commercialized by or in collaboration with Progenics. Subcutaneous Relistor has received regulatory marketing approval for specific indications, and references to Relistor do not imply that any other form or possible use of the drug has received approval. The approved U.S. label for Relistor also provides that use of Relistor beyond four months has not been studied. Full U.S. prescribing information is available at www.Relistor.com. Other approved labels for Relistor apply in ex-US markets. Azedra is a trademark of Molecular Insight.

In summarizing the status of our commercialization and product candidates:

	Research and discovery means initial research related to specific molecular targets, synthesis of new chemical entities, assay development or screening for identification and optimization of lead compound(s). This work precedes preclinical investigations, which involves lead compound(s) undergoing toxicology, formulation and other testing in preparation for clinical trials.
	Phase 1-3 clinical trials are safety and efficacy tests in humans:
	1:	Initial evaluation of safety in humans; study method of action and metabolization.
	2:	Evaluation of safety, dosing and activity or efficacy; continue safety evaluation.
	3:	Larger scale evaluation of safety, efficacy and dosage.

Oncology

A significant part of our oncology efforts involves research and development directed at prostate specific membrane antigen, or PSMA, a protein found at high levels on the surface of prostate cancer cells and also on the neovasculature of a number of other types of solid tumors. Our main product candidate in these efforts is our fully human monoclonal antibody-drug conjugate, PSMA ADC, which is designed to deliver a chemotherapeutic agent to cancer cells by targeting the three-dimensional structure of the PSMA protein on these cells and binding to and internalizing within the cell. PSMA ADC utilizes our own technology together with intellectual property licensed to us from Sloan-Kettering Institute for Cancer Research and Seattle Genetics, Inc. We are conducting a phase 2 open-label, multicenter clinical trial of this compound to assess anti-tumor activity, tolerability and safety in patients with metastatic castration-resistant prostate cancer. See Clinical Trial Activities for information concerning our studies of PSMA ADC, our other principal product candidates, and Relistor.

Through our recent acquisition of Molecular Insight (MIP), we have significantly expanded our focus on PSMA as an oncology target while broadening our oncology pipeline with its targeted radiotherapy and molecular imaging compounds, including:

MIP-1404, a radio-labeled small molecule which binds PSMA and acts as an imaging agent to diagnose and detect prostate cancer, including in other soft tissue and bone. An ongoing phase 2 global multicentered study is assessing the diagnostic accuracy of MIP-1404 imaging in men with high-risk prostate cancer scheduled for radical prostectomy and extended pelvic lymph node dissection compared to histopathology. MIP has out-licensed MIP-1404 to FUJIFILM RI Pharma Co., Ltd. for development and commercialization in Japan.

MIP-1095, -1555 and -1558, small molecules in preclinical development as a therapeutic for metastatic prostate cancer and other PSMA-expressing cancers targeting the PSMA antigen with a radioactive payload. It has generated evidence of dose-dependent enhanced tumor kill and prolonged survival in animal models of human prostate cancer, and an ongoing investigator-initiated study in Germany of men with late-stage metastatic prostate cancer demonstrated tumor reduction for more than 14 days and a greater than 50% decrease in prostate-specific antigen (PSA, a secreted protein that is distinct from PSMA) levels in eight of 14 evaluable patients.

Azedra, a phase 2 radiotherapeutic product candidate in development as a treatment for pheochromocytoma -- rare tumors found primarily in the adrenal glands (called paraganglioma elsewhere) -- in adults, and neuroblastoma in children. Azedra has Orphan Drug designation and Fast Track status in the United States and European Union Orphan Drug designation for the treatment of neuroblastoma. If approved, Azedra would be the first therapeutic in the U.S. for the treatment of pheochromocytoma. Azedra utilizes MIP's own technology together with intellectual property licensed to it from the University of Western Ontario and McMaster University.

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We have recently suspended investment in our proprietary phosphoinositide 3-kinase (PI3K) inhibitor research and are evaluating alternative paths forward for this program. We continue to consider opportunities for strategic collaborations, out-licenses and other arrangements with biopharmaceutical companies involving our proprietary research, development and clinical programs, and may in the future also in-license or acquire additional oncology compounds and/or programs.

Relistor

Relistor, the first approved treatment for opioid-induced constipation (OIC) that addresses its underlying mechanism, decreases the constipating side effects induced by opioid pain medications such as morphine and codeine without diminishing their ability to relieve pain. Relistor subcutaneous injection is approved for sale in the U.S., E.U., Canada, Australia and elsewhere in pre-filled syringes, which are designed to ease preparation and administration for patients and caregivers. Under our License Agreement, Salix is responsible for developing and commercializing Relistor, including completing clinical development necessary to support regulatory marketing approvals for potential new indications (such as OIC in patients with chronic, non-cancer pain) and formulations of the drug (such as an oral formulation of methylnaltrexone, the active ingredient in Relistor). As previously announced, the U.S. Food and Drug Administration last July issued a Complete Response Letter for the supplemental New Drug Application for Relistor injection for subcutaneous use for the treatment of OIC in adult patients with chronic, non-cancer pain, in which the FDA requested additional clinical data. After an End-of-Review meeting in October 2012, the FDA's Division of Gastroenterology and Inborn Errors Products expressed a concern that there may be a risk associated with the chronic use of mu-opioid receptor antagonists in patients who are taking opioids for chronic pain, and, in order to understand this potential risk, the Division communicated that a very large, well-controlled, chronic administration trial will have to be conducted to assess the safety of any mu-opioid receptor antagonist prior to market approval for the treatment of patients with OIC who are taking opioids for chronic, non-cancer pain. Salix subsequently held discussions with the Division and expressed the view that the post-marketing, clinical and preclinical data currently available for Relistor adequately demonstrate an appropriate and expected safety profile sufficient to permit the approval of the current Relistor sNDA. In response to Salix's formal appeal of the FDA's complete response letter, the FDA informed Salix and Progenics in June 2013 that it will seek input from an Advisory Committee, which is now expected to convene on March 10-11, 2014. The FDA has also stated that it will take action under the appeal within 30 days after receiving input from the Committee.

At the time Salix and Progenics announced the FDA's determination to convene an Advisory Committee, we expressed our belief that some of the areas being considered for discussion during the meeting would include the potential for drugs in Relistor's class to cause withdrawal symptoms; the strength of a potential cardiovascular signal seen with another drug in this class of drugs and the available safety data with Relistor in regards to a potential cardiovascular (CV) signal; and the need and timing (pre-approval vs. post-approval) of major adverse cardiac events (MACE) studies with drugs of this class. We also announced that the FDA had communicated that it was convening the Advisory Committee for the following reasons:

"The potential cardiovascular safety signal observed in the 12-month safety trial of another peripheral mu-opioid antagonist for the treatment of opioid-induced constipation in patients with chronic non-cancer pain raises concern for this class of drug products."

The RELISTOR "supplemental application contains only uncontrolled long-term safety data, and while there is no cardiovascular signal apparent in this data, the lack of a control population does not allow a definitive evaluation to be made to rule out a potential cardiovascular safety signal."

"FDA needs to provide consistent advice regarding the need for Major Adverse Cardiovascular Event (MACE) studies to applicants developing drug products in this class for this indication. For this reason, a broader discussion of the potential for cardiovascular events across the drug class is necessary."

See Risk Factors.

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Relistor net sales and related royalties earned during the years 2010-2012 are set forth below. Our recognition of royalty revenue for financial reporting purposes is explained in Management's Discussion and Analysis of Financial Condition and Results of Operations (MD&A) and our financial statements included elsewhere in this document. Royalties are based on net sales reported by commercialization collaborators.

	First Quarter		Second Quarter		Third Quarter		Fourth Quarter		Full Year
	(in thousands)
2012:
Net Sales	$	12,300	$	10,800	$	4,900	$	5,200	$	33,200
Royalties Earned		1,834		1,619		728		782		4,963
2011:
Net Sales	$	3,300	$	5,200	$	9,700	$	8,800	$	27,000
Royalties Earned		-		527		1,240		1,279		3,046
2010:
Net Sales	$	4,200	$	3,800	$	4,100	$	4,000	$	16,100
Royalties Earned		625		581		620		-		1,826

Clinical Trial Activities

Progenics' practice has been to announce via press release the commencement and results of all of its significant clinical trials, including our phase 1 and 2 trials of PSMA ADC and our phase 1, 2 and 3 trials of Relistor, and to include such releases as exhibits to contemporaneous SEC Form 8-K filings. Following is a summary of clinical trial activities through late 2013 involving our principal product candidates and Relistor.

PSMA ADC. We are conducting a phase 2 trial of PSMA ADC to assess its anti-tumor activity and tolerability. In this open-label, multicenter U.S. study, participants with metastatic castration-resistant prostate cancer (mCRPC) have received initial doses of drug starting at either 2.5 mg/kg or 2.3 mg/kg; in some cases subsequent doses were adjusted based on tolerability. The study endpoints evaluate the anti-tumor effect of the compound as measured by changes in prostate specific antigen (PSA) levels, number of circulating tumor cells (CTC), pain scores, and tumor size as measured under RECIST criteria. Safety is also being assessed. Progenics announced in December 2013 that it has completed enrollment of 83 chemotherapy experienced patients in this trial and has initiated treatment in an additional trial cohort of up to 35 chemotherapy naive patients who have progressed on hormonal therapies.

Adverse events (AEs) associated with PSMA ADC observed in this phase 2 study through mid-2013 have been consistent with those observed in the phase 1 study noted below; the most common grade 3 or higher AEs in this study have been neutropenia (grade 4: 6.7% at 2.3 mg/kg and 11.4% at 2.5 mg/kg) and peripheral neuropathy (grade 3 or higher: 6.7% at 2.3 mg/kg and 5.7% at 2.5 mg/kg). Eight patients experienced serious adverse events (SAEs) which included febrile neutropenia, neutropenia, sinus tachycardia, gastrointestinal disorders, fatigue, infections and dehydration. Two deaths occurred after treatment with PSMA ADC. The first, a patient hospitalized ten days following his first dose of study drug (2.5 mg/kg) with febrile neutropenia and E. coli positive blood cultures, progressed despite treatment to septic shock and died; both the investigator and Progenics considered this patient's septic shock as probably related to PSMA ADC. The second patient developed a rash and fever and was hospitalized for neutropenic fever, where further assessment revealed Strep Viridans bacteria (suspected to be from a tunnel catheter) in blood. Approximately two weeks after receiving study drug (also 2.5 mg/kg), this patient was intubated due to hypoxia and respiratory failure, and died three days after being removed from a ventilator. The investigator considered sepsis as unlikely, bacteremia as probably, febrile neutropenia as definitely related to PSMA ADC; Progenics assessed sepsis as probably, bacteremia as unlikely, and febrile neutropenia as definitely related to PSMA ADC. A third patient died before receiving study drug.

The phase 2 trial was undertaken after review and analysis of results from a phase 1 dose-ranging study of the compound in 52 mCRPC patients whose cancer had progressed despite prior treatment with taxane-based chemotherapy regimens.

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The initial 12-week clinical trial period of the phase 1 study evaluated up to four intravenous doses of PSMA ADC administered at three-week intervals. Following completion of the four doses, patients were offered, at their physicians' discretion, the option to continue treatment with PSMA ADC for up to an additional 39 weeks. The anti-tumor effect of the compound as measured by changes in PSA levels and number of CTCs was observed in the study across doses ranging from 1.8 mg/kg to 2.8 mg/kg, and durable responses were seen in some of these heavily pre-treated patients. PSMA ADC was generally well tolerated in patients at doses up to and including 2.5 mg/kg. Dose limiting toxicities, primarily neutropenia, were seen at 2.8 mg/kg. The most commonly reported AEs were anorexia and fatigue. Five patients experienced SAEs, two of which resulted in death. One patient dosed at 1.8 mg/kg died from multi-organ failure due to acute pancreatitis: while no data suggested this event was drug-related, a possible relationship could not be definitively ruled out. A second patient died 11 days after receiving study drug at 2.8 mg/kg: septic shock was cited as the cause of death. The investigator considered septic shock as probably related and febrile neutropenia as definitely related to PSMA ADC.

Through mid-2013, 14 percent of the 95 patients treated with PSMA ADC in these trials have reported SAEs, including acute pancreatitis, sepsis/septic shock (each as noted above), tachycardia, abnormal ECG, atrial fibrillation, chest pain, confusion, deep vein thrombosis, pulmonary embolism, hematuria, increased International Normalized Ratio (INR), leukopenia, metabolic acidosis, myocardial infarction, pneumonia and renal failure. In conducting these studies, Progenics has taken into account SAEs reported to date as treatment-related or possibly treatment-related; based on data currently available to it, the Company is continuing development of PSMA ADC and has not determined what effects, if any, treatment-related SAEs reported to date or that may be reported in the future may have on the development of PSMA ADC going forward. See Risk Factors.

MIP-1404. MIP conducted four phase 1 studies with MIP-1404 to establish proof-of-concept and dosimetry, and to assess a simplified kit preparation as compared to multi-step preparation. A phase 2 safety and efficacy study was commenced by MIP in 2012 to assess the diagnostic accuracy of MIP-1404 imaging in men with high-risk prostate cancer scheduled for radical prostatectomy (RP) and extended pelvic lymph node dissection (EPLND) compared to histopathology. The primary objective of this phase 2 international multi-center, multi-reader, open-label trial is to assess the clinical safety of MIP-1404 as well as the compound's ability to detect prostate cancer within the prostate gland. Patient enrollment has been completed with 105 participants dosed at 20 centers in the U.S. and Europe. An additional phase 1 study in 14 patients to assess safety and diagnostic accuracy of MIP-1404 whole body and pelvic SPECT/CT imaging and pelvic MRI in normal healthy men without current evidence of prostate cancer has completed dosing. There have to date been no treatment related AEs reported in these studies, other than one mild injection site reaction.

Azedra. In 2006, MIP commenced a phase 1 study with Azedra in 11 patients with pheochromocytoma / paraganglioma and metastatic carcinoid tumors to assess the safety, radiation dosimetry, and distribution metabolism of a single imaging dose of this compound. Following completion of this study, two dose-finding studies were conducted by MIP to determine a maximum tolerated therapeutic dose, and to assess safety, dosimetry and preliminary efficacy of Azedra in 21 patients with pheochromocytoma / paraganglioma and 15 with high-risk neuroblastoma, respectively.

MIP subsequently commenced a phase 2 study of Azedra under a 2009 Special Protocol Assessment (SPA) with the FDA regarding the design of this intended registrational phase 2 trial to evaluate the efficacy and safety of the administration of two therapeutic doses of Azedra in patients with pheochromocytoma / paraganglioma. The primary objective of this U.S. study is to determine the clinical benefit of Azedra based on the proportion of study participants with a reduction of antihypertensive medication by at least 50% for at least six months. This phase 2 trial has enrolled 41 patients, and the long-term follow up phase of the study is ongoing. As of June 2013, 49% of patients receiving study drug reported SAEs, the most common of which were hematologic (12%); other SAEs included constipation, dyspnea and myelodysplastic syndrome (each at 4.5%).

In late 2010 MIP suspended the trial, having enrolled 41 of the 58 patients required to be treated under the SPA, due to lack of funding. Progenics announced in November 2013 that it is resuming this trial, and plans for patient recruitment to continue after making drug supply manufacturing arrangements for the trial.

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Relistor. Salix and Progenics completed in 2011 a phase 3 U.S. trial to evaluate the efficacy and safety of oral methylnaltrexone for the treatment of opioid-induced constipation in patients with chronic, non-cancer pain. This 804-patient trial assessed a once-daily oral methylnaltrexone dose of 150, 300 or 450 mg compared to placebo for 12 weeks: patients received one daily dose during the first four weeks and dosing on an as needed basis for the remaining eight weeks. Both the 300 and 450 mg treatment arms demonstrated statistically significant results for the primary endpoint of average proportion of rescue-free bowel movements (RFBMs) per patient within four hours of administration over four weeks of dosing, when compared to the placebo treatment arm. Efficacy was also seen in both the 300 and 450 mg treatment groups for other endpoints, including change in weekly RFBMs from baseline over the first four weeks and one assessing response (responder/non-responder) to study drug during weeks one to four, where "responder" was defined as having three or more RFBMs per week, with an increase of at least one RFBM per week over baseline, for at least three out of the first four weeks. Overall, efficacy of oral methylnaltrexone in this study was comparable to that reported in clinical studies of subcutaneous methylnaltrexone in patients with chronic, non-cancer pain, and the overall observed safety profile seen in patients treated with oral methylnaltrexone was comparable to placebo.

The phase 3 trial was undertaken after review and analysis of results from clinical trials initiated by Progenics' former collaboration partner, Wyeth Pharmaceuticals, and Progenics utilizing formulations of oral methylnaltrexone in patients with chronic, non-cancer pain receiving opioid treatment.

In one of these trials, of the oral formulation utilized in the phase 3 trial described above, 48% of the 25 patients receiving methylnaltrexone tablets laxated within four hours of treatment. In this study, there were no drug related SAEs reported, and the most frequent AEs were nausea and headache (10.8% each); others were vomiting (4.6%), abdominal pain and muscle spasms (3.1% each). Based on the data from this study and other information regarding oral methylnaltrexone, Progenics concluded that the methylnaltrexone tablet was active and generally well tolerated, and that its safety, pharmacokinetics and activity profiles were comparable to that of subcutaneous methylnaltrexone, and the Company decided to commence the phase 3 trial described above.

License and Other Agreements

Following is a summary of significant agreements relating to our pipeline.

Oncology

Our PSMA Development Company LLC subsidiary has a collaboration agreement with Seattle Genetics, Inc. under which SGI has granted us an exclusive worldwide license to its proprietary ADC technology. We have the right to use this technology, which is based in part on technology licensed by SGI from third parties, to link chemotherapeutic agents to our monoclonal antibodies that target prostate specific membrane antigen and will utilize technology licensed to us from Sloan-Kettering. We are responsible for research, product development, manufacturing and commercialization of all products, and are obligated to make maintenance and milestone payments and to pay royalties to SGI and its licensors, as applicable, on a percentage of net sales. The SGI agreement terminates at the latest of (i) the tenth anniversary of the first commercial sale of each licensed product in each country or (ii) the latest date of expiration of patents underlying the licensed products. We may terminate the agreement upon advance written notice; SGI may terminate if we fail to cure a breach of an SGI in-license after written notice; and either party may terminate after written notice upon an uncured breach or in the event of the other party's bankruptcy.

PSMA LLC also has a worldwide exclusive licensing agreement with Abgenix (now Amgen Fremont, Inc.) to use its XenoMouse^® technology for generating fully human antibodies to PSMA. We are obligated to make development and commercialization milestone payments with respect to products incorporating an antibody generated utilizing that technology, along with royalties based upon net sales of such products. Abgenix may terminate this agreement for cause, after an opportunity to cure, upon 30 days prior written notice; we have the right to terminate upon 30 days prior written notice. The agreement continues until the later of the expiration of specified patents or seven years from the first commercial sale of eligible products.

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We acquired Molecular Insight in January 2013 by purchasing all of its outstanding capital stock for 4,566,210 shares of Progenics common stock (with 500,000 held in escrow) in a private transaction. Under the agreement, we also agreed to pay to the former stockholders potential milestones, in cash or Progenics stock at our option, of up to $23 million contingent upon achieving specified commercialization events and up to $70 million contingent upon achieving specified sales targets relating to all MIP products. The agreement contains customary representations and warranties, covenants, and indemnification and other provisions.

Relistor

Under our License Agreement, Salix Pharmaceuticals is responsible for further developing and commercializing subcutaneous Relistor worldwide other than Japan, including completing clinical development necessary to support regulatory marketing approvals for potential new indications and formulations, and marketing and selling the product. Salix is marketing Relistor directly through its specialty sales force in the U.S., and outside the U.S., directly through distribution and marketing partners and sublicensing regional companies. Salix is paying us royalties ranging from 15 to 19 percent on its net sales of Relistor as well as 60% of any upfront, milestone, reimbursement or other revenue (net of costs of goods sold and territory-specific research and development expense reimbursement) it receives from sublicensees in respect of any country outside the U.S. We are also eligible to receive (i) a development milestone of up to $40 million upon U.S. marketing approval for subcutaneous Relistor in chronic, non-cancer pain patients (the proposed indication addressed in the Complete Response Letter referred to above), (ii) a development milestone of up to $50 million upon U.S. marketing approval of an oral formulation of Relistor, and (iii) up to $200 million of commercialization milestone payments upon achievement of specified U.S. sales targets. In the event that either marketing approval is subject to a Black Box Warning or Risk Evaluation and Mitigation Strategy (REMS), payment of a substantial portion of specified milestone amounts would be deferred, and subject, to achievement of the first commercialization milestone payable upon annual U.S. sales first exceeding $100 million. See Risk Factors.

We have licensed to Ono Pharmaceutical the rights to subcutaneous Relistor in Japan, where Ono is responsible for developing and commercializing subcutaneous Relistor, including conducting clinical development to support regulatory marketing approval and will own the subcutaneous filings and approvals relating to Relistor. We are entitled to receive up to $20 million upon achievement of development milestones as well as royalties and commercialization milestones on sales of subcutaneous Relistor in Japan. Ono has the option to acquire the rights to develop and commercialize other formulations of Relistor in Japan, on terms to be negotiated separately. Supervision of and consultation with respect to Ono's development and commercialization responsibilities are carried out by joint committees. The Ono License contains, among other terms, provisions which permit termination by either party upon the occurrence of certain events.

Among the rights we have licensed to our Relistor collaborators/licensees are our exclusive rights to develop and commercialize methylnaltrexone, the active ingredient of Relistor, which we in-licensed from the University of Chicago and for which we are obligated to make milestone and royalty payments to the University. Under the Chicago agreement, originally entered into by the University and a private company, UR Labs, Inc., in 1985, the University granted URL an exclusive option to acquire an exclusive license to a then-extant patent covering methylnaltrexone, any patent application filed respecting other uses of the compound and corresponding foreign patents. The agreement provides for the option/licensee to undertake certain development and potential commercialization obligations, pay to the University single-digit royalties on commercial sales of resulting products and single-digit percentages of milestone and sublicensing revenues, and share patent policing responsibilities. URL exclusively sublicensed us its rights under the Chicago agreement in 2001, and transferred substantially all of its assets, including its interest in the Chicago agreement and the sublicense, to Progenics in 2005. The Chicago agreement, as amended in connection with our Relistor collaborations with Wyeth, Ono and Salix, including substantially all of Progenics' payment obligations thereunder, expires by its terms upon the expiration of the last to expire of the patents licensed thereunder, the last-to-expire of which expires in 2017.

Patents and Proprietary Technology

Protection of our intellectual property rights is important to our business. We seek U.S. patent protection for many of our inventions, and generally file patent applications in Canada, Japan, European countries that are party to the European Patent Convention and other countries on a selective basis in order to protect inventions we consider to be important to the development of business in those areas. Generally, patents issued in the U.S. are effective for either (i) 20 years from the earliest asserted filing date, if the application was filed on or after June 8, 1995, or (ii) the longer of 17 years from the date of issue or 20 years from the earliest asserted filing date, if the application was filed prior to that date.

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In certain instances, the U.S. patent term can be extended up to a maximum of five years to recapture a portion of the term during which FDA regulatory review was being conducted. The duration of foreign patents varies in accordance with the provisions of applicable local law, although most countries provide for patent terms of 20 years from the earliest asserted filing date and allow patent extensions similar to those permitted in the U.S.

Patents may not enable us to preclude competitors from commercializing drugs in direct competition with our products, and consequently may not provide us with any meaningful competitive advantage. See Risk Factors. We also rely on trade secrets, proprietary know-how and continuing technological innovation to develop and maintain a competitive position in our product areas. We require our employees, consultants and corporate partners who have access to our proprietary information to sign confidentiality agreements.

Information with respect to our current patent portfolio is set forth below.

Clinical and Research	Number of Patents		Expiration	Number of Patent Applications
Candidates; Relistor	U.S.	International	Dates ⁽¹⁾	U.S.	International

Oncology (PSMA; key MIP programs)	13	7	2013-2029	20	90

Relistor	10	34	2015-2030	26	206

Other	13	60	2016-2023	3	29

⁽¹⁾Patent term extensions and pending patent applications may extend periods of patent protection.

With respect to PSMA ADC, currently issued composition-of-matter patents comprising co-owned and in-licensed properties have expiration ranges of 2022 to 2023 in the U.S. and 2022 to 2026 ex-U.S. Corresponding patent applications as well as patent applications directed to methods of use (except for the U.S. patent expiring in 2023) are pending worldwide, which if issued would have expiration ranges from 2022 to 2029. We view all of these patents as significant. A U.S. patent which expired earlier this year was not directly related to, and is not used in or required for the manufacture, use or prospective commercialization of, the PSMA ADC product candidate.

Owned and in-licensed properties relating to the MIP-1404 product candidate have expiration ranges of 2020 to 2029; we view as most significant the composition-of-matter patent on the compound, as well as 99mTc labeled forms, which expires in 2029. Additional U.S. patents are directed to various inventions relating to the product candidate, and corresponding patent applications are pending worldwide.

With regard to our Relistor-related intellectual property, the composition-of-matter patent for the active ingredient of Relistor, methylnaltrexone, was invented in the 1970's and has expired. The University, as well as Progenics and its collaborators, have extended the methylnaltrexone patent estate with additional patents and pending patent applications covering various inventions relating to the product. Salix has listed in the FDA Orange Book four U.S. patents relating to subcutaneous Relistor, which have expiration dates ranging from 2017 to 2030, and one patent (expiring in 2024) with Health Canada. A patent issued in September 2013 provides protection for the oral methylnaltrexone product until 2031.

We are aware of intellectual property rights held by third parties that relate to products or technologies we are developing. For example, we are aware of others investigating and developing technologies and drug candidates directed toward PSMA or related compounds as well as methylnaltrexone and other peripheral opioid antagonists, and of patents and applications held or filed by others in those areas. The validity of issued patents, patentability of claimed inventions in pending applications and applicability of any of them to our programs are uncertain and subject to change, and patent rights asserted against us could adversely affect our ability to commercialize or collaborate with others on specific products.

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Research, development and commercialization of a biopharmaceutical product often require choosing between alternative development and optimization routes at various stages in the development process. Preferred routes depend upon current -- and may be affected by subsequent -- discoveries and test results and cannot be identified with certainty at the outset. There are numerous third-party patents in fields in which we work, and we may need to obtain license under patents of others in order to pursue a preferred development route of one or more of our product candidates. The need to obtain a license would decrease the ultimate value and profitability of an affected product. If we cannot negotiate such a license, we might have to pursue a less desirable development route or terminate the entire program altogether.

Government Regulation

Progenics and its product candidates are subject to comprehensive regulation by the U.S. FDA and comparable authorities in other countries. Pharmaceutical regulation currently is a topic of substantial interest in lawmaking and regulatory bodies in the U.S. and internationally, and numerous proposals exist for changes in FDA and non-U.S. regulation of pre-clinical and clinical testing, approval, safety, effectiveness, manufacturing, storage, recordkeeping, labeling, marketing, export, advertising, promotion and other aspects of biologics, small molecule drugs and medical devices, many of which, if adopted, could significantly alter our business and the current regulatory structure described below. See Risk Factors.

FDA Regulation. FDA approval, which involves review of scientific, clinical and commercial data, manufacturing processes and facilities, is required before a product candidate may be marketed in the U.S. This process is costly, time consuming and subject to unanticipated delays, and a drug candidate may fail to progress at any point.

None of our product candidates other than Relistor has received marketing approval from the FDA or any other regulatory authority. The process required by the FDA before product candidates may be approved for marketing in the U.S. generally involves:

·	pre-clinical laboratory and animal tests;
·	submission to and favorable review by the FDA of an investigational new drug application before clinical trials may begin;
·	adequate and well-controlled human clinical trials to establish the safety and efficacy of the product for its intended indication (animal and other nonclinical studies also are typically conducted during each phase of human clinical trials);
·	submission to the FDA of a marketing application; and
·	FDA review of the marketing application in order to determine, among other things, whether the product is safe and effective for its intended uses.

Pre-clinical tests include laboratory evaluation of product chemistry and animal studies to gain preliminary information about a compound's pharmacology and toxicology and to identify safety problems that would preclude testing in humans. Product candidates must generally be manufactured according to current Good Manufacturing Practices (cGMP), and pre-clinical safety tests must be conducted by laboratories that comply with FDA good laboratory practices regulations.

Results of pre-clinical tests are submitted to the FDA as part of an Investigational New Drug application (IND) which must become effective before clinical trials may commence. The IND submission must include, among other things, a description of the sponsor's investigational plan; protocols for each planned study; chemistry, manufacturing and control information; pharmacology and toxicology information and a summary of previous human experience with the investigational drug. Unless the FDA objects to, makes comments or raises questions concerning an IND, it becomes effective 30 days following submission, and initial clinical studies may begin. Companies often obtain affirmative FDA approval, however, before beginning such studies.

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Clinical trials involve the administration of the investigational new drug to healthy volunteers or to individuals under the supervision of a qualified principal investigator. Clinical trials must be conducted in accordance with the FDA's Good Clinical Practice requirements under protocols submitted to the FDA that detail, among other things, the objectives of the study, parameters used to monitor safety and effectiveness criteria to be evaluated. Each clinical study must be conducted under the auspices of an Institutional Review Board, which considers, among other things, ethical factors, safety of human subjects, possible liability of the institution and informed consent disclosure which must be made to participants in the trial.

Clinical trials are typically conducted in three sequential phases, which may overlap. During phase 1, when the drug is initially administered to human subjects, the product is tested for safety, dosage tolerance, absorption, metabolism, distribution and excretion. Phase 2 involves studies in a limited population to evaluate preliminarily the efficacy of the product for specific, targeted indications, determine dosage tolerance and optimal dosage and identify possible adverse effects and safety risks.

When a product candidate is found in phase 2 evaluation to have an effect and an acceptable safety profile, phase 3 trials are undertaken in order to further evaluate clinical efficacy and test for safety within an expanded population. Safety studies are conducted in accordance with the FDA's International Conference on Harmonization (ICH) Guidelines. Phase 2 results do not guarantee a similar outcome in phase 3 trials. The FDA may suspend clinical trials at any point in this process if it concludes that clinical subjects are being exposed to an unacceptable health risk.

A New Drug Application, or NDA, is an application to the FDA to market a new drug. A Biologic License Application, or BLA, is an application to market a biological product. The new drug or biological product may not be marketed in the U.S. until the FDA has approved the NDA or issued a biologic license. The NDA must contain, among other things, information on chemistry, manufacturing and controls; non-clinical pharmacology and toxicology; human pharmacokinetics and bioavailability; and clinical data. The BLA must contain, among other things, data derived from nonclinical laboratory and clinical studies which demonstrate that the product meets prescribed standards of safety, purity and potency, and a full description of manufacturing methods. Supplemental NDAs (sNDAs) are submitted to obtain regulatory approval for additional indications for a previously approved drug, and are reviewed by the FDA in a similar manner.

The results of the pre-clinical studies and clinical studies, the chemistry and manufacturing data, and the proposed labeling, among other things, are submitted to the FDA in the form of an NDA or BLA. The FDA may refuse to accept the application for filing if certain administrative and content criteria are not satisfied, and even after accepting the application for review, the FDA may require additional testing or information before approval of the application, in either case based upon changes in applicable law or FDA policy during the period of product development and FDA regulatory review. The applicant's analysis of the results of clinical studies is subject to review and interpretation by the FDA, which may differ from the applicant's analysis, and in any event, the FDA must deny an NDA or BLA if applicable regulatory requirements are not ultimately satisfied. If regulatory approval of a product is granted, such approval may be made subject to various conditions, including post-marketing testing and surveillance to monitor the safety of the product, or may entail limitations on the indicated uses for which it may be marketed. Product approvals may also be withdrawn if compliance with regulatory standards is not maintained or if problems occur following initial marketing.

Underlying this process are FDA regulations relating to drug approval which are complex and multi-faceted. Two such policies which may apply to some of our current or future product candidates are "Fast Track" approval for new drugs or biologics intended for the treatment of serious or life-threatening conditions which demonstrate the potential to address unmet medical needs, and Orphan Drug designation, available under U.S., E.U. and other laws, for drug candidates intended to treat rare diseases or conditions, and which if approved are granted a period of market exclusivity, subject to various conditions. Orphan Drug designation does not shorten or otherwise convey any advantage in the regulatory approval process.

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Both before and after approval is obtained, a product, its manufacturer and the sponsor of the marketing application for the product are subject to comprehensive regulatory oversight. Violations of existing or newly-adopted regulatory requirements at any stage, including the pre-clinical and clinical testing process, the approval process, or thereafter, may result in various adverse consequences, including FDA delay in approving or refusal to approve a product, withdrawal of an approved product from the market or the imposition of criminal penalties against the manufacturer or sponsor. Later discovery of previously unknown problems may result in restrictions on the product, manufacturer or sponsor, including withdrawal of the product from the market.

Regulation Outside the U.S. Whether or not FDA approval has been obtained, approval of a pharmaceutical product by comparable government regulatory authorities abroad must be obtained prior to marketing the product there. The approval procedure varies from country to country, and the time required may be longer or shorter than that required for FDA approval. The requirements for regulatory approval by governmental agencies in other countries prior to commercialization of products there can be rigorous, costly and uncertain, and approvals may not be granted on a timely basis or at all.

In E.U. countries, Canada, Australia and Japan, regulatory requirements and approval processes are similar in principle to those in the U.S. Regulatory approval in Japan requires that clinical trials of new drugs be conducted in Japanese patients. Depending on the type of drug for which approval is sought, there are currently two potential tracks for marketing approval in the E.U. countries: mutual recognition and the centralized procedure. These review mechanisms may ultimately lead to approval in all E.U. countries, but each method grants all participating countries some decision-making authority in product approval. The centralized procedure, which is mandatory for biotechnology derived products, results in a recommendation in all member states, while the E.U. mutual recognition process involves country-by-country approval.

In other countries, regulatory requirements may require additional pre-clinical or clinical testing regardless of whether FDA or European approval has been obtained. This is the case in Japan, where Ono is responsible for developing and commercializing the subcutaneous form of Relistor and where trials are required to involve patient populations which we and our other collaborators have not examined in detail. If a product is manufactured in the U.S., it is also subject to FDA and other U.S. export provisions. In most countries outside the U.S., coverage, pricing and reimbursement approvals are also required, which may affect the profitability of the affected product.

Other Regulation. In addition to regulations enforced by the FDA, we are also subject to regulation under the U.S. Occupational Safety and Health Act, Environmental Protection Act, Toxic Substances Control Act, Resource Conservation and Recovery Act and various other current and potential future U.S. federal, state or local regulations. In addition, Molecular Insight's research is dependent on maintenance of licenses from various authorities permitting the acquisition, use and storage of quantities of radioactive isotopes that are critical for its manufacture and testing of research products. Biopharmaceutical research and development generally involves the controlled use of hazardous materials, chemicals, viruses and various radioactive compounds. Even strict compliance with safety procedures for storing, handling, using and disposing of such materials prescribed by applicable regulations cannot completely eliminate the risk of accidental contaminations or injury from these materials, which may result in liability for resulting legal and regulatory violations as well as damages.

Manufacturing

Under our License Agreement, Salix is responsible for the manufacture and supply, at its expense, of all active pharmaceutical ingredient (API) and finished and packaged products for its Relistor commercialization efforts, including contracting with contract manufacturing organizations (CMOs) for supply of Relistor API and subcutaneous and oral finished drug product. See Risk Factors.

We expect to engage third-party CMOs to manufacture additional clinical trial supplies of our PSMA monoclonal antibody and to continue using CMOs for other portions of the PSMA ADC manufacturing process. If we are unable to arrange for satisfactory CMO services, or otherwise were to determine to establish a new manufacturing capacity, we would need to expand our manufacturing staff and facilities or obtain new facilities. In order to establish a full-scale commercial manufacturing facility for any of our product candidates, we would need to spend substantial additional funds, hire and train significant numbers of employees and comply with the extensive FDA regulations applicable to such a facility.

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Sales and Marketing

We from time to time seek strategic collaborations and other funding support for product candidates in our pipeline. We expect that we would market other products for which we obtain regulatory approval through co-marketing, co-promotion, licensing and distribution arrangements with third-party collaborators, and might also consider contracting with professional detailing and sales organizations to perform promotional and/or medical-scientific support functions for them. See Risk Factors.

Competition

Competition in the biopharmaceutical industry is intense and characterized by ongoing research and development and technological change. We face competition from many for-profit companies and major universities and research institutions in the U.S. and abroad. We face competition from companies marketing existing products or developing new products for diseases targeted by our technologies. Many of our competitors have substantially greater resources, experience in conducting pre-clinical studies and clinical trials and obtaining regulatory approvals for their products, operating experience, research and development and marketing capabilities and production capabilities than we do. Our products and product candidates under development may not compete successfully with existing products or products under development by other companies, universities and other institutions. Drug manufacturers that are first in the market with a therapeutic for a specific indication generally obtain and maintain a significant competitive advantage over later entrants and therefore, the speed with which industry participants move to develop products, complete clinical trials, approve processes and commercialize products is an important competitive factor.

Relistor is the first FDA-approved product for any indication involving OIC. We are, however, aware of approved and marketed products, as well as candidates in pre-clinical or clinical development, that target the side effects of opioid pain therapy. Cubist Pharmaceuticals, which acquired Adolor Corporation in 2011, markets ENTEREG^® (alvimopan) for the treatment of postoperative ileus, and is in phase 3 testing of a compound for OIC in chronic-pain patients. Sucampo Pharmaceuticals, Inc., in collaboration with Takeda Pharmaceutical Company Limited, markets AMITIZA^®(lubiprostone), a selective chloride channel activator, for chronic idiopathic (non-opioid related) constipation, and has filed an sNDA, which has been granted priority review by the FDA, for approval of this drug for opioid-induced constipation. A Nektar Therapeutics-AstraZeneca PLC collaboration is conducting phase 3 efficacy and safety studies of an oral peripheral mu-opioid receptor antagonist in patients with OIC, and has a related combination product in early stage development. Theravance, Inc. has completed phase 2 clinical testing of an oral peripheral mu-opioid antagonist. In Europe, Mundipharma International Limited markets TARGIN^® (oxycodone/naloxone), a combination of an opioid and a systemic opioid antagonist. Other prescription as well as over-the-counter (OTC) constipation products are also prescribed first line for OIC.

As to our oncology pipeline, radiation and surgery are two traditional forms of treatment for prostate cancer. If the disease spreads, hormone (androgen) suppression therapy is often used to slow the cancer's progression, but this form of treatment can eventually become ineffective. We are aware of several competitors who are developing or have received approval for alternative treatments for castration-resistant prostate cancer, some of which are directed against PSMA, including Johnson & Johnson subsidiary Janssen Biotech, Inc.'s Zytiga^® (abiraterone acetate), approved in 2011 for use in combination with prednisone as a second-line (after treatment with docetaxel) advanced prostate cancer treatment, and in December 2012 for use with prednisone for metastatic castration-resistant disease before the use of chemotherapy); Medivation, Inc.'s Xtandi^® (enzalutamide), approved in August 2012 for patients with metastatic castration-resistant prostate cancer previously treated with docetaxel; and Algeta ASA's Alpharadin^® (radium-223 chloride), submitted in late 2012 for marketing authorization for therapy of bone metastases in prostate cancer patients. A competitive product to MIP-1404 is Jazz Pharmaceuticals' ProstaScint^®, which is approved for detection of metastatic prostate cancer or relapsed or high-risk prostate cancer patients.

A significant amount of research in the biopharmaceutical field is carried out at academic and government institutions. An element of our research and development strategy has been to in-license technology and product candidates from academic and government institutions. These institutions are sensitive to the commercial value of their findings and pursue patent protection and negotiate licensing arrangements to collect royalties for use of technology they develop. They may also market competitive commercial products on their own or in collaboration with competitors and compete with us in recruiting highly qualified scientific personnel, which may result in increased costs or decreased availability of technology or product candidates from these institutions to other industry participants.

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Product Liability

The testing, manufacturing and marketing of our product candidates and products involves an inherent risk of product liability attributable to unwanted and potentially serious health effects. To the extent we elect to test, manufacture or market product candidates and products independently, we bear the risk of product liability directly. We maintain product liability insurance coverage in the amount of $10.0 million per occurrence, subject to a deductible and a $10.0 million aggregate limitation. Where local statutory requirements exceed the limits of our existing insurance or local policies of insurance are required, we maintain additional clinical trial liability insurance to meet these requirements. This insurance is subject to deductibles and coverage limitations. The availability and cost of maintaining insurance may change over time.

Human Resources

At December 31, 2012, we had 76 full-time employees, 15 of whom hold Ph.D. degrees and one an M.D. degree. At that date, 57 employees were engaged in research and development, medical, regulatory affairs and manufacturing related activities and 19 were engaged in finance, legal, administration and business development. We consider our relations with our employees to be good. None of our employees is covered by a collective bargaining agreement.

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Item 1A. Risk Factors

The future of our business and operations depends on the success of our Relistor collaborations and our oncology research and development programs, including the programs and product candidates we have recently acquired in the Molecular Insight transaction.

Our business and operations entail a variety of serious risks and uncertainties and are inherently risky. The research and development programs on which we focus, including those we have recently acquired in the Molecular Insight transaction, involve novel approaches to human therapeutics. Our product candidates, including those we have recently acquired as part of MIP, are in pre-clinical or clinical development, and in some respects involve technologies with which we have limited prior experience. We are subject to the risks of failure inherent in the development of product candidates based on new technologies. There is little precedent for the successful commercialization of products based on our technologies, and there are a number of technological challenges that we must overcome to complete most of our development efforts. We may not be able successfully to develop further any of our product candidates. We and our Relistor and other collaborators must successfully complete clinical trials and obtain regulatory approvals for potential commercial products. Once approved, if at all, commercial product sales are subject to general and industry-specific local and international economic pressures such as those experienced worldwide over the recent past. With our strategy to focus on oncology research and development, these risks continue to be significant and may increase to the extent the oncology space becomes more competitive or less favored in the commercial marketplace.

Our integration of the Molecular Insight acquisition will continue to require significant efforts, including coordination of research and development, as well as finance, accounting, and information technology and other functions, all of which involve expense and significant management time. The success of this acquisition will depend on, among other things, the strength of MIP's product candidates and their underlying technologies; results of clinical trials, regulatory applications and approvals; and our ability to fund or otherwise develop acquired candidates and programs, achieve available cost savings, efficiencies and synergies, and attract and retain employees and consultants with expertise and experience appropriate to these efforts. Our failure to manage successfully the MIP acquisition or any of the acquired product candidates, technologies or programs could have an adverse impact on our business, and on the price of our stock.

We are dependent on Salix, Ono and other business partners to develop and commercialize Relistor, exposing us to significant risks.

We rely on Salix to complete development and obtain regulatory approvals for additional formulations of and indications for Relistor and, in the Japanese market, we rely on Ono to conduct clinical trials and obtain regulatory approvals. We are and will be dependent upon Salix, Ono and any other business partners with which we may collaborate in the future to perform and fund development, including clinical testing of Relistor, make related regulatory filings and manufacture and market products, including for new indications and in new formulations, in their respective territories. Revenue from the sale of Relistor depends entirely upon the efforts of Salix and its sublicensees, which have significant discretion in determining the efforts and resources they apply to sales of Relistor. Ono will have similar discretion with respect to sales in Japan. Neither may be effective in obtaining approvals for new indications or formulations, marketing existing or future products or arranging for necessary sublicense or distribution relationships. Our business relationships with Salix, Ono and other partners may not be scientifically, clinically or commercially successful. For example, Salix has a variety of marketed products. Salix is not, however, a large diversified pharmaceutical company and does not have resources commensurate with such companies. Salix has its own corporate objectives, which may not be consistent with our best interests, and may change its strategic focus or pursue alternative technologies in a manner that results in reduced or delayed revenue to us. Changes of this nature might also occur if Salix were acquired or if its management changed. We may have future disagreements with Salix or Ono, both of which have significantly greater financial and managerial resources which either could draw upon in the event of a dispute. Such disagreements could lead to lengthy and expensive litigation or other dispute-resolution proceedings as well as extensive financial and operational consequences to us and have a material adverse effect on our business, results of operations and financial condition. In addition, independent actions may be taken by Salix and/or Ono concerning product development, marketing strategies, manufacturing and supply issues, and rights relating to intellectual property, including, as discussed below, Relistor's path forward in light of the July, 2012 Complete Response Letter from the FDA.

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Progenics in October 2013 commenced an arbitration with Ono under the provisions of the parties' License Agreement for development and commercialization of subcutaneous Relistor in Japan, following a communication from Ono that it has determined to discontinue development because of "commercial concerns" that Ono contends would permit it to cease development and terminate the Agreement. Ono's discontinuation of development and/or protracted dispute resolution proceedings could result in reduced or delayed, or in the elimination of, milestone and/or royalty revenue from subcutaneous Relistor development in Japan. Under our License Agreement with Salix, in the event our Agreement with Ono terminates or rights thereunder otherwise revert to Progenics, the Salix Agreement automatically without payment by Salix extends to the license grants, territory and other rights provided in the Ono Agreement, as a result of which Salix and not Progenics would receive such rights.

As a result of the FDA's Complete Response Letter on Relistor for chronic pain, the Relistor program may be discontinued or otherwise at risk.

As previously announced, and noted elsewhere in this document, the FDA in July 2012 issued a Complete Response Letter in response to Salix's supplemental New Drug Application for Relistor for the treatment of OIC in adult patients with chronic, non-cancer pain. This development may result in Salix and/or Ono taking independent actions concerning product development, marketing strategies or other matters for Relistor, including termination of their efforts to develop and commercialize the drug. At an End-of-Review meeting in October 2012, the FDA's Division of Gastroenterology and Inborn Errors Products has expressed a concern that there may be a risk associated with the chronic use of mu-opioid receptor antagonists in patients who are taking opioids for chronic pain, and, in order to understand this potential risk, the Division communicated that a very large, well-controlled, chronic administration trial will have to be conducted to assess the safety of any mu-opioid receptor antagonist prior to market approval for the treatment of patients with OIC who are taking opioids for chronic, non-cancer pain. In addition, the FDA informed Salix and Progenics in June 2013 that it will seek input from an Advisory Committee, which is now expected to convene on March 10-11, 2014, and at that time expressed our belief that some of the areas being considered for discussion during the meeting would include the potential for drugs in Relistor's class to cause withdrawal symptoms; the strength of a potential cardiovascular signal seen with another drug in this class of drugs and the available safety data with Relistor in regards to a potential cardiovascular (CV) signal; and the need and timing (pre-approval vs. post-approval) of major adverse cardiac events (MACE) studies with drugs of this class.

Salix has disclosed in regulatory filings that it might terminate its development program for Relistor subcutaneous injection for treatment of OIC in chronic non-cancer pain patients, and that additional information and additional guidance from the FDA could result in the termination of its oral OIC Relistor development program. As noted in our risk factor on regulatory approvals below, if clinical trials indicate, or regulatory bodies are concerned about, actual or possible serious problems with the safety or efficacy of a product candidate, such as the concerns expressed in the FDA's CRL and as described above, we or our collaborators may stop or significantly slow development or commercialization of affected products. As a result of such concerns, the development programs for subcutaneous and/or oral Relistor for chronic, non-cancer pain patients may be significantly delayed or terminated altogether. In such an event, we could be faced with either further developing and commercializing the drug on our own or with one or more substitute collaborators, either of which paths would subject us to the development, commercialization, collaboration and/or financing risks discussed in these risk factors. Any such significant action adverse to development and commercialization of Relistor could have a material adverse impact on our business, and on the price of our stock.

We are subject to extensive regulation, which can be costly and time consuming, may not lead to marketing approval for our product candidates, and can subject us to unanticipated limitations, restrictions, delays and fines.

Our business, products and product candidates are subject to comprehensive regulation by the FDA and comparable authorities in other countries. These agencies and other entities regulate the pre-clinical and clinical testing, safety, effectiveness, approval, manufacture, labeling, marketing, export, storage, recordkeeping, advertising, promotion and other aspects of our products and product candidates. We cannot guarantee that approvals of product candidates, processes or facilities will be granted on a timely basis, or at all. If we experience delays or failures in obtaining approvals, commercialization of our product candidates will be slowed or stopped.

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For example, as described in Business – Clinical Trial Activities, in clinical studies of one of our principal product candidates, PSMA ADC, investigators have reported serious adverse events (SAEs), including three deaths, in a small proportion of patients treated with the drug. Based on data currently available to us, the Company is continuing development of PSMA ADC and has not determined what effects, if any, treatment-related SAEs reported to date or that may be reported in the future may have on the development of PSMA ADC going forward. If, however, we, together with or independently of investigators participating in our clinical trials, or regulators evaluating PSMA ADC were to determine that this candidate cannot safely be administered to patients with sufficient therapeutic effect, we may determine to attempt to reformulate or otherwise change the candidate and/or its administration to alleviate such concerns, which could result in costs and delays that could impair the value of the candidate. If such costs and delays were sufficiently large, we could determine to abandon the PSMA ADC program. Concerns about the safety and/or efficacy of PSMA ADC could also make it more difficult or impossible for us to enter into licensing, collaboration or other arrangements with third parties for further development and commercialization of PSMA ADC. Any of these possibilities could have material adverse effects on Progenics' business, its financial condition, and/or the price of our stock.

Even if we obtain regulatory approval for a product candidate, the approval may include significant limitations on indicated uses for which the product could be marketed or other significant marketing restrictions, such as a Risk Evaluation and Mitigation Strategy (REMS). For example, Relistor is only approved for OIC in patients with advanced illness and not for chronic, non-cancer pain, and our product candidates, if approved at all, may be subject to those or other such limitations and restrictions.

If we or our collaborators violate regulatory requirements at any stage, whether before or after marketing approval is obtained, we or they may be subject to forced removal of a product from the market, product seizure, civil and criminal penalties and other adverse consequences. Under our license agreement with Salix, we are dependent on Salix for compliance with these regulatory requirements as they apply to Relistor. Salix has disclosed that in February it received a subpoena from the U.S. Attorney's Office for the Southern District of New York requesting documents regarding its sales and promotional practices for Relistor and certain of its other products, that it is in the process of responding to the subpoena and intends to cooperate fully with the subpoena and related government investigation, that at the time of its disclosure it cannot predict or determine the timing or outcome of the inquiry or its impact on Salix's financial condition or results of operations, and that the laws and regulations regarding off-label promotion and the authorities' interpretation of them might increase its expenses, impair its ability to effectively market its products, and limit its revenue.

Our products may face regulatory, legal or commercial challenges even after approval.

Even if a product receives regulatory approval:

It might not obtain labeling claims necessary to make the product commercially viable (in general, labeling claims define the medical conditions for which a drug product may be marketed, and are therefore very important to the commercial success of a product), or may be required to carry Boxed or other warnings that adversely affect its commercial success.

Approval may be limited to uses of the product for treatment or prevention of diseases or conditions that are relatively less financially advantageous to us than approval of greater or different scope or subject to an FDA-imposed REMS that imposes limits on the distribution or use of the product.

Side effects (including different or aggravated effects such as SAEs encountered in our PSMA ADC program) identified after the product is on the market might hurt sales or result in mandatory safety labeling changes, additional pre-clinical testing or clinical trials, imposition of a REMS, product recalls or withdrawals from the market.

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Efficacy or safety concerns (including those arising from SAEs heretofore or hereafter encountered in our PSMA ADC program) regarding a marketed product, or manufacturing or other problems, may lead to a recall, withdrawal of marketing approval, reformulation of the product, additional pre-clinical testing or clinical trials, changes in labeling, imposition of a REMS, the need for additional marketing applications, declining sales or other adverse events. These potential consequences may occur whether or not the concerns originate from subsequent testing or other activities by us, governmental regulators, other entities or organizations or otherwise, and whether or not they are scientifically justified. If products lose previously received marketing and other approvals, our business, results of operations and financial condition would be materially adversely affected.

We or our collaborators will be subject to ongoing FDA obligations and continuous regulatory review, and might be required to undertake post-marketing trials to verify the product's efficacy or safety or other regulatory obligations.

Competing products in development may adversely affect acceptance of our products.

We are aware of a number of products and product candidates described in this Annual Report under Business – Competition which compete or may potentially compete with Relistor. Any of these approved products or product candidates, or others which may be developed in the future may achieve a significant competitive advantage relative to Relistor, and, in any event, the existing or future marketing and sales capabilities of these competitors may impair Salix's and/or Ono's ability to compete effectively in the market.

We are also aware of competitors, including those described under Business – Competition, which are developing alternative treatments for disease targets to which our research and development programs are directed, any of which – or others which may be developed in the future – may achieve a significant competitive advantage relative to any product we may develop.

Developing product candidates, including those we have acquired in the Molecular Insight transaction, will require us to obtain additional financing. Our access to capital funding is uncertain.

We expect to continue to incur significant development expenditures for our product candidates, and such expenditures will increase as a result of the Molecular Insight acquisition. We do not have committed external sources of funding for most of these projects. Our expenditures will be funded from cash on hand, or we may seek additional external funding for them, most likely through collaborative, license or royalty financing agreements with one or more pharmaceutical companies, equity securities issuances, debt financings, or government grants or contracts. To the extent we raise additional capital by issuing equity securities in the future, existing stockholders could experience substantial dilution in addition to the dilution experienced as a result of our recent equity offering and the Molecular Insight acquisition, and new investors could have rights superior to existing stockholders. Any debt financing that we are able to obtain may involve operating covenants that restrict our business and significant repayment obligations. To the extent that we raise additional funds through any new collaboration and licensing arrangements, we may be required to relinquish some rights to our technologies or product candidates, or grant licenses on terms that are not favorable to us.

We cannot predict when we will need additional funds, how much we will need, the form any financing may take or whether additional funds will be available at all, especially in light of current conditions in global credit and financial markets. Our need for future funding will depend on numerous factors, such as the availability of new product development projects; the achievement of events identified in our collaboration agreements that trigger payments to us from our collaboration partners, most of which are out of our control and rely entirely on the efforts of our partners; the progress and success of clinical trials and pre-clinical activities (including studies and manufacture of materials) of our product candidates conducted by our collaborators or us; the progress of research programs carried out by us; any changes in the breadth of our research and development programs; the progress of the research and development efforts of our collaborators; our ability to acquire or license other technologies or compounds that we seek to pursue; competing technological and market developments; the costs and timing of obtaining, enforcing and defending our patent and intellectual property rights; the costs and timing of regulatory approvals and filings by us and our collaborators; our ability to manage our growth; and any unforeseen litigation. These factors may be more important with respect to product candidates and programs that involve technologies with which we have limited prior experience, such as those we have acquired in the Molecular Insight transaction. Insufficient funds may require us to delay, scale back or eliminate some or all of our research and development programs, to lose rights under existing licenses or to relinquish greater or all rights to product candidates at an earlier stage of development or on less favorable terms than we would otherwise choose or may adversely affect our ability to operate as a going concern. We may not be able at the necessary time to obtain additional funding on acceptable terms, or at all. Our inability to raise additional capital on terms reasonably acceptable to us would seriously jeopardize our business.

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If we are unable to negotiate collaboration agreements, our cash burn rate could increase and our rate of product development could decrease.

Our ability to generate revenue in the near term depends on the timing of achievement, if any, of certain payment triggering events under our existing collaboration agreements and our ability to enter into additional collaboration agreements with third parties. We may not be successful in negotiating additional collaboration arrangements with pharmaceutical and biotechnology companies to develop and commercialize product candidates and technologies. If we do not enter into new collaboration arrangements, we would have to devote more of our resources to clinical product development and product launch activities, the volume of which will increase as we continue research and development of candidates and programs acquired in the Molecular Insight transaction, and to seeking additional sources of capital to fund those activities. If we were not successful in seeking such capital, our cash burn rate would increase or we would need to take steps to reduce our rate of product development. Our ability to enter into new collaborations may be dependent on many factors, such as the results of clinical trials, competitive factors and the fit of our programs with the risk tolerance of a potential collaborator, including in relation to regulatory issues, the patent portfolio, the clinical pipeline, the stage of the available data, overall corporate goals and financial position. If we are not able to generate revenue under our collaborations when and in accordance with our expectations or the expectations of industry analysts, this failure could harm our business and have an immediate adverse effect on the trading price of our common stock.

Drug development is a long and inherently uncertain process with a high risk of failure at every stage of development.

Drug development is a highly uncertain scientific and medical endeavor, and failure can unexpectedly occur at any stage of clinical development. Typically, there is a high rate of attrition for product candidates in preclinical and clinical trials due to scientific feasibility, safety, efficacy, changing standards of medical care and other variables. The risk of failure increases for our product candidates that are based on new technologies, as well as technologies with which we have limited prior experience, such as those we have acquired in the Molecular Insight transaction. Pre-clinical studies and clinical trials are long, expensive and highly uncertain processes that can take many years. It will take us, or our collaborators, several years to complete clinical trials and the time required for completing testing and obtaining approvals is uncertain. The start or end of a clinical trial is often delayed or halted due to changing regulatory requirements, manufacturing challenges, required clinical trial administrative actions, slower than anticipated patient enrollment, changing standards of care, availability or prevalence of use of a comparator drug or required prior therapy, clinical outcomes, or our and our partners' financial constraints. The FDA and other U.S. and foreign regulatory agencies have substantial discretion, at any phase of development, to terminate clinical trials, require additional clinical development or other testing, delay or withhold registration and marketing approval and mandate product withdrawals, including recalls. Results attained in early human clinical trials may not be indicative of results in later clinical trials. In addition, many of our investigational or experimental drugs are at an early stage of development, and successful commercialization of early stage product candidates requires significant research, development, testing and approvals by regulators, and additional investment. Our products in the research or pre-clinical development stage may not yield results that would permit or justify clinical testing. Our failure to demonstrate adequately the safety and efficacy of a product under development would delay or prevent marketing approval, which could adversely affect our operating results and credibility. The failure of one or more of our product candidates could have a material adverse effect on our business, financial condition and results of operations.

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If we or our collaborators do not obtain regulatory approval for our product candidates on a timely basis, or at all, or if the terms of any approval impose significant restrictions or limitations on use, our business, results of operations and financial condition will be adversely affected. Setbacks in clinical development programs could have a material adverse effect on our business.

Regulatory approvals are necessary to market product candidates and require demonstration of a product's safety and efficacy through extensive pre-clinical and clinical trials. We or our collaborators may not obtain regulatory approval for product candidates on a timely basis, or at all, and the terms of any approval (which in some countries includes pricing approval) may impose significant restrictions, limitations on use or other commercially unattractive conditions. We, our collaborators or regulators may also amend, suspend or terminate clinical trials if we or they believe that the participating subjects are being exposed to unacceptable health risks, and after reviewing trial results, we or our collaborators may abandon projects which we previously believed to be promising for commercial or other reasons unrelated to patient risks. During this process, we may find, for example, that results of pre-clinical studies are inconclusive or not indicative of results in human clinical trials, clinical investigators or contract research organizations do not comply with protocols or applicable regulatory requirements, or that product candidates do not have the desired efficacy or have undesirable side effects or other characteristics that preclude marketing approval or limit their potential commercial use if approved. In such circumstances, the entire development program for that product candidate could be adversely affected, resulting in delays in trials or regulatory filings for further marketing approval and a possible need to reconfigure our clinical trial programs to conduct additional trials or abandon the program involved. Conducting additional clinical trials or making significant revisions to a clinical development plan would lead to delays in regulatory filings. If clinical trials indicate, or regulatory bodies are concerned about, actual or possible serious problems with the safety or efficacy of a product candidate, such as the concerns expressed in the FDA's July 2012 Complete Response Letter or during consideration of the oral Relistor development program, we or our collaborators may stop or significantly slow development or commercialization of affected products. As a result of such concerns, the development programs for subcutaneous and/or oral Relistor for chronic, non-cancer pain patients may be significantly delayed or terminated altogether.

Even if we agree to a path forward with Salix and the FDA, if the results of any future Relistor trials are not satisfactory or we or our collaborators encounter problems enrolling subjects, clinical trial supply issues, setbacks in developing drug formulations, including raw material-supply, manufacturing, stability or other difficulties, or issues complying with protocols or applicable regulatory requirements, the entire development program for Relistor could be adversely affected in a material manner. Such scenarios could also befall our other clinical-stage product candidates. If any of our collaborators breach or terminate its agreement with us or otherwise fail to conduct successfully and in a timely manner the collaborative activities for which they are responsible, the preclinical or clinical development or commercialization of the affected product candidate or research program could be delayed or terminated. We generally do not control the amount and timing of resources that our collaborators devote to our programs or product candidates. We also do not know whether current or future collaboration partners, if any, might pursue alternative technologies or develop alternative products either on their own or in collaboration with others, including our competitors, as a means for developing treatments for the diseases or conditions targeted by our collaborative arrangements. Setbacks of these types could have a material adverse effect on our business, results of operations and financial condition.

We or our collaborators must design and conduct successful clinical trials for our product candidates to obtain regulatory approval. We rely on third parties for conduct of clinical trials, which reduces our control over them and may expose us to conflicts of interest. Clinical trial results may be unfavorable or inconclusive, and often take longer than expected.

We have limited experience in conducting clinical trials, and we rely on or obtain the assistance of others to design, conduct, supervise or monitor some or all aspects of some of our clinical trials, including our ongoing phase 2 trial of PSMA ADC. We have less control over the timing and other aspects of clinical trials for which we rely on third parties, such as CROs, clinical data management organizations, medical institutions or clinical investigators, than if we conducted them entirely on our own. These third parties may also have relationships with other entities, some of which may be our competitors. In all events, we are responsible for ensuring that each of our clinical trials is conducted in accordance with the general investigational plan and protocols for the trial. The FDA requires us to comply with good clinical practices for conducting and recording and reporting the results of clinical trials to assure that data and reported results are credible and accurate and that the rights, integrity and confidentiality of trial participants are protected. Our reliance on third parties that we do not control does not relieve us of these responsibilities and requirements.

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To obtain regulatory approval of drug candidates, we must demonstrate through preclinical studies and clinical trials that they are safe and effective. Adverse or inconclusive clinical trial results concerning any of our drug candidates, or trials which regulators find deficient in scope, design or one or more other material respects, could require additional trials, resulting in increased costs, significant delays in submissions of approval applications, approvals in narrower indications than originally sought, or denials of approval, none of which we can predict. As a result, any projections that we publicly announce of commencement and duration of clinical trials are not certain. We have experienced clinical trial delays in the past as a result of slower than anticipated enrollment and such delays may recur. Delays can be caused by, among other things, deaths or other adverse medical events; regulatory or patent issues; interim or final results of ongoing clinical trials; failure to enroll clinical sites as expected; competition for enrollment from other clinical trials; scheduling conflicts with participating clinicians and institutions; disagreements, disputes or other matters arising from collaborations; our inability to obtain necessary funding; or manufacturing problems.

Under our license agreement, Salix generally has responsibility for conducting Relistor clinical trials, including all trials outside of the U.S. other than Japan, where Ono has the responsibility for clinical trials. In addition, certain clinical trials for our product candidates may be conducted by government-sponsored agencies, and consequently will be dependent on governmental participation and funding. These arrangements expose us to the same considerations we face when contracting with third parties for our own trials.

Our product candidates may not obtain regulatory approvals needed for marketing.

None of our product candidates, other than Relistor for the treatment of OIC in patients with advanced illnesses, has been approved by applicable regulatory authorities for marketing. The process of obtaining FDA and foreign regulatory approvals often takes many years and can vary substantially based upon the type, complexity and novelty of the products involved. We have had only limited experience in filing and pursuing applications and other submissions necessary to gain marketing approvals. Products under development may never obtain marketing approval from the FDA or other regulatory authorities necessary for commercialization.

Even if our product candidates obtain marketing approval, our ability to generate revenue will be diminished if our products are not accepted in the marketplace or our collaboration partners fail to obtain acceptable prices or an adequate level of reimbursement for products from third-party payors or government agencies.

The commercial success of our products will depend upon their acceptance by the medical community and third-party payors as clinically useful, cost effective and safe. Market acceptance of approved products, such as Relistor for patients with advanced illnesses, is affected by the timing of regulatory approvals, product launches and reimbursement programs for existing and expanded uses or generic, over-the-counter or other competitors; price increases for the product and relative prices of competing products; product development efforts for new indications; availability of sufficient commercial quantities of the product; success in arranging for necessary sublicense or distribution relationships; and general and industry-specific local and international economic pressures such as those experienced worldwide over the last five years. If health care providers believe that patients can be managed adequately with alternative, currently available therapies, they may not prescribe our products, especially if the alternative therapies are viewed as more effective, as having a better safety or tolerability profile, as being more convenient to the patient or health care providers or as being less expensive. Third- party insurance coverage may not be available to patients for any products we develop, alone or with collaborators. For pharmaceuticals administered in an institutional setting, the ability of the institution to be adequately reimbursed from government and health administration authorities, private health insurers and other third-party payors could also play a significant role in demand for our products. Significant uncertainty exists as to the reimbursement status of newly-approved pharmaceuticals. Government and other third-party payors increasingly are attempting to contain healthcare costs by limiting both coverage and the level of reimbursement for new drugs and by refusing, in some cases, to provide coverage for uses of approved products for indications for which the FDA has not granted labeling approval. In some foreign markets, pricing and profitability of prescription pharmaceuticals are subject to government control. In the U.S., we expect that there will continue to be a number of federal and state proposals to implement similar government control and that the emphasis on managed care in the U.S. will continue to put pressure on the pricing of pharmaceutical products. Cost control initiatives could decrease the price that our collaborators receive for any products in the future and adversely affect the ability of our collaborators to commercialize our products and our realization of royalties from commercialization. If any of our products do not achieve market acceptance, we will likely lose our entire investment in that product.

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Marketplace acceptance depends in part on competition in our industry, which is intense, and competing products in development may adversely affect acceptance of our products.

The extent to which any of our products achieves market acceptance will depend on competitive factors. Competition in the biopharmaceutical industry is intense and characterized by ongoing research and development and technological change. We face competition from many for-profit companies and major universities and research institutions in the U.S. and abroad. We face competition from companies marketing existing products or developing new products for diseases and conditions targeted by our technologies. We are aware of a number of products and product candidates, including those described in this Annual Report under Business – Competition, which compete or may potentially compete with Relistor, PSMA ADC or our other product candidates. For instance, there are product candidates in pre-clinical or clinical development that target the side effects of opioid pain therapy, and a marketed product for the treatment of post-operative ileus could compete with Relistor. We are aware of several competitors, including those described under Business – Competition, which have received approval for or are developing alternative treatments for castration-resistant prostate cancer, some of which are directed against PSMA, MIP-1404 and our other product candidates. Any of these competing approved products or product candidates, or others which may be developed in the future, may achieve a significant competitive advantage relative to Relistor, PSMA ADC or any of our other product candidates.

Competition with respect to our technologies and products is based on, among other things, product efficacy, safety, reliability, method of administration, availability, price and clinical benefit relative to cost; timing and scope of regulatory approval; sales, marketing and manufacturing capabilities; collaborator capabilities; insurance and other reimbursement coverage; and patent protection. Competitive disadvantages in any of these factors could materially harm our business and financial condition. Many of our competitors have substantially greater research and development capabilities and experience and greater manufacturing, marketing, financial and managerial resources than we do. These competitors may develop products that are superior to those we are developing and render our products or technologies non-competitive or obsolete. Our products and product candidates under development may not compete successfully with existing products or product candidates under development by other companies, universities and other institutions. Drug manufacturers that are first in the market with a therapeutic for a specific indication generally obtain and maintain a significant competitive advantage over later entrants and therefore, the speed with which industry participants move to develop products, complete clinical trials, approve processes and commercialize products is an important competitive factor. If our product candidates receive marketing approval but cannot compete effectively in the marketplace, our operating results and financial position would suffer.

If we or our collaborators are unable to obtain sufficient quantities of the raw and bulk materials needed to make our product candidates or Relistor, development of our product candidates or commercialization of our approved product could be slowed or stopped.

Salix or Ono may not be able to fulfill manufacturing obligations for Relistor, either on their own or through third-party suppliers. A delay or disruption of supplies of Relistor would have a material adverse effect on the Relistor franchise, and therefore on our business as a whole. Our existing arrangements with suppliers for our other product candidates may not result in the supply of sufficient quantities of our product candidates needed to accomplish our clinical development programs, and we may not have the right and in any event do not currently have the capability to manufacture these products if our suppliers are unable or unwilling to do so. We currently arrange for supplies of critical raw materials used in production of our product candidates from single sources. We do not have long-term contracts with any of these suppliers. Any delay or disruption in the availability of raw materials would slow or stop product development and commercialization of the relevant product.

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Manufacturing resources could limit or adversely affect our ability to commercialize products.

We or our collaborators engage third parties to manufacture our approved product and product candidates. We or our collaborators may not be able to obtain adequate supplies from third-party manufacturers in a timely fashion for development or commercialization purposes, and commercial quantities of products may not be available from contract manufacturers at acceptable costs. Under our license agreement with Salix, Salix is responsible for obtaining supplies of Relistor, including contracting with contract manufacturing organizations for supply of Relistor active pharmaceutical ingredient and subcutaneous and oral finished drug product. These arrangements may not be on terms that are advantageous and, as a result of our royalty and other interests in Relistor's commercial success, will subject us to risks that the counterparties may not perform optimally in terms of quality or reliability. In engaging third parties for these activities, we do not control many aspects of the manufacturing process, including compliance with current Good Manufacturing Practices (cGMP) and other regulatory requirements. In order to commercialize our product candidates successfully, we or our collaborators need to be able to manufacture or arrange for the manufacture of products in commercial quantities, in compliance with regulatory requirements, at acceptable costs and in a timely manner. Manufacture of our product candidates can be complex, difficult to accomplish even in small quantities, difficult to scale-up for large-scale production and subject to delays, inefficiencies and low yields of quality products. The cost of manufacturing some of our product candidates may make them prohibitively expensive. If adequate supplies of any of our product candidates or related materials are not available on a timely basis or at all, our clinical trials could be seriously delayed, since these materials are time consuming to manufacture and cannot be readily obtained from third-party sources. If we were to decide to establish a commercial-scale manufacturing facility in the future, we would require substantial additional funds and be required to hire and train significant numbers of employees and comply with applicable regulations.

Failure of any manufacturer of Relistor or our product candidates to comply with applicable regulatory requirements could subject us to penalties and have a material adverse effect on supplies of our product or products candidates.

Third-party manufacturers are required to comply with cGMP or similar regulatory requirements outside of the U.S. If manufacturers of our product or product candidates cannot successfully manufacture material that conforms to the strict regulatory requirements of the FDA and any applicable foreign regulatory authority, they may not be able to obtain any required approval for their manufacturing facilities. If these facilities are not approved for commercial manufacture, we may need to find alternative manufacturing facilities, which could result in delays of several years in obtaining approval for a product candidate. We do not control the manufacturing process and are completely dependent on our third-party manufacturing partners or contractors for compliance with the applicable regulatory requirements for the manufacture of Relistor and our product candidates. Manufacturers are subject to ongoing periodic unannounced inspections by the FDA and corresponding state and foreign agencies for compliance with cGMP and similar regulatory requirements. Failure of any manufacturer of Relistor or any of our product candidates to comply with applicable cGMP or other regulatory requirements could result in sanctions being imposed on our collaborators or us, including fines, injunctions, civil penalties, delays, suspensions or withdrawals of approvals, operating restrictions, interruptions in supply and criminal prosecutions, any of which could significantly and adversely affect supplies of Relistor or such product candidate and have a material adverse impact on our business, financial condition and results of operations.

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We are dependent on patents and other intellectual property rights.

The validity, enforceability and commercial value of our patents and other intellectual property rights are highly uncertain.

We own or have direct or sub-licenses to a number of issued patents. We must obtain, maintain and enforce patent and other rights to protect our intellectual property. The patent position of biotechnology and pharmaceutical firms is highly uncertain and involves many complex legal and technical issues. There are many laws, regulations and judicial decisions that dictate and otherwise influence the manner in which patent applications are filed and prosecuted and in which patents are granted and enforced, all of which are subject to change from time to time. There is no clear policy involving the breadth of claims allowed, or the degree of protection afforded, under patents in this area. In addition, we are aware of others who have patent applications or patents containing claims similar to or overlapping those in our patents and patent applications. Accordingly, patent applications owned by or licensed to us may not result in patents being issued. Even if we own or license a relevant issued patent, we may not be able to preclude competitors from commercializing drugs that may compete directly with one or more of our products or product candidates, in which event such rights may not provide us with any meaningful competitive advantage. For example, we and Salix have no patent protection outside the U.S. for subcutaneous Relistor, our approved product, although we do have regulatory data exclusivity which provides a competitive barrier to generic entry for limited periods of time. In the absence or upon successful challenge of patent protection, drugs may be subject to generic competition, which could adversely affect pricing and sales volumes of the affected products.

It is generally difficult to determine the relative strength or scope of a biotechnology or pharmaceutical patent position in absolute terms at any given time. The issuance of a patent is not conclusive as to its validity or enforceability, which can be challenged in litigation or via administrative proceedings. The license agreements from which we derive or out-license intellectual property provide for various royalty, milestone and other payment, commercialization, sublicensing, patent prosecution and enforcement, insurance, indemnification and other obligations and rights, and are subject to certain reservations of rights. While we generally have the right to defend and enforce patents licensed to or by us, either in the first instance or if the licensor or licensee chooses not to do so, we must usually bear the cost of doing so. Under our license agreement with Salix, Salix generally has the first right to control the defense and enforcement of our Relistor patents. With respect to Japan, Ono has certain limited rights to prosecute, maintain and enforce relevant intellectual property. We may incur substantial costs in seeking to uphold the validity of patents or to prevent infringement. If the outcome of a dispute or contest is adverse to us, third parties may be able to use our patented invention without payment to us. Third parties may also avoid our patents through design innovation.

Patents have a limited life and expire by law.

In addition to uncertainties as to scope, validity, enforceability and changes in law, patents by law have limited lives. Upon expiration of patent protection, our drug candidates and/or products may be subject to generic competition, which could adversely affect pricing and sales volumes of the affected products.

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We depend on intellectual property licensed from third parties and unpatented technology, trade secrets and confidential information. If we lose any of these rights, including by failing to achieve milestone requirements or to satisfy other conditions, or if they or data embodying or relevant to them are compromised by disruptions or breaches of information or data security, our business, results of operations and financial condition could be harmed.

Most of our product candidates, including Relistor, incorporate intellectual property licensed from third parties. For example, PSMA ADC utilizes technology licensed to us from Sloan-Kettering Institute for Cancer Research, through Cytogen Corporation, and Seattle Genetics, Inc. We can lose the right to patents and other intellectual property licensed to us if the related license agreement is terminated due to a breach by us or otherwise. Our ability, and that of our collaboration partners, to commercialize products incorporating licensed intellectual property would be impaired if the related license agreements were terminated. In addition, we are required to make substantial cash payments, achieve milestones and satisfy other conditions, including filing for and obtaining marketing approvals and introducing products, to maintain rights under our intellectual property licenses. Due to the nature of these agreements and the uncertainties of research and development, we may not be able to achieve milestones or satisfy conditions to which we have contractually committed, and as a result may be unable to maintain our rights under these licenses. If we do not comply with our license agreements, the licensors may terminate them, which could result in our losing our rights to, and therefore being unable to commercialize, related products.

We also rely on unpatented technology, trade secrets and confidential information. Third parties may independently develop substantially equivalent information and techniques or otherwise gain access to our technology or disclose our technology, and we may be unable to effectively protect our rights in unpatented technology, trade secrets and confidential information. We require each of our employees, consultants and advisors to execute a confidentiality agreement at the commencement of an employment or consulting relationship with us. These agreements may, however, not provide effective protection in the event of unauthorized use or disclosure of confidential information. Any loss of trade secret protection or other unpatented technology rights could harm our business, results of operations and financial condition.

Progenics and other businesses and organizations worldwide, and in particular technology-intensive activities such as biotechnology research and development, are increasingly dependent on critical, complex and interdependent information technology systems, including Internet-based systems, to facilitate or perform basic research and development functions, business processes, internal and external communications, and other critical functions. Progenics relies on such systems for most aspects of its business. The size and complexity of computer, communications and other electronic networked data generation, storage and transfer systems make them potentially vulnerable to breakdown, malicious intrusion, computer viruses and data security breaches by unauthorized third parties, employees or others. Such events may permit unauthorized persons to access, misappropriate and/or destroy sensitive data and result in the impairment or disruption of important business processes, loss of trade secrets or other proprietary intellectual property or public exposure of personal information (including sensitive personal information) of employees, business partners, clinical trial patients, customers and others. Any of the foregoing could have a material adverse effect on our business, prospects, operating results, and financial condition.

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If we do not achieve milestones or satisfy conditions regarding some of our product candidates, we may not maintain our rights under related licenses.

We are required to make substantial cash payments, achieve milestones and satisfy other conditions, including filing for and obtaining marketing approvals and introducing products, to maintain rights under our intellectual property licenses. Due to the nature of these agreements and the uncertainties of research and development, we may not be able to achieve milestones or satisfy conditions to which we have contractually committed, and as a result may be unable to maintain our rights under these licenses. If we do not comply with our license agreements, the licensors may terminate them, which could result in our losing our rights to, and therefore being unable to commercialize, related products.

If we infringe third-party patent or other intellectual property rights, we may need to alter or terminate a product development program.

There may be patent or other intellectual property rights belonging to others that require us to alter our products, pay licensing fees or cease certain activities. If our products infringe patent or other intellectual property rights of others, the owners of those rights could bring legal actions against us claiming damages and seeking to enjoin manufacturing and marketing of the affected products. If these legal actions are successful, in addition to any potential liability for damages, we could be required to obtain a license in order to continue to manufacture or market the affected products. We may not prevail in any action brought against us, and any license required under any rights that we infringe may not be available on acceptable terms or at all. We are aware of intellectual property rights held by third parties that relate to products or technologies we are developing. For example, we are aware of other groups investigating PSMA or related compounds, monoclonal antibodies directed at PSMA and targets relevant to PSMA ADC, and methylnaltrexone and other peripheral opioid antagonists, and of patents held, and patent applications filed, by these groups in those areas. While the validity of these issued patents, patentability of these pending patent applications and applicability of any of them to our programs are uncertain, if asserted against us, any related patent or other intellectual property rights could adversely affect our ability to commercialize our products.

Research, development and commercialization of a biopharmaceutical often requires choosing between alternative development and optimization routes at various stages in the development process. Preferred routes depend on subsequent discoveries and test results and cannot be predicted with certainty at the outset. There are numerous third-party patents in our field, and we may need to obtain a license under a patent in order to pursue the preferred development route of one or more of our products or product candidates. The need to obtain a license would decrease the ultimate profitability of the applicable product. If we cannot negotiate a license, we might have to pursue a less desirable development route or terminate the program altogether.

We are dependent upon third parties for a variety of functions. These arrangements may not provide us with the benefits we expect.

We rely on third parties to perform a variety of functions. We are party to numerous agreements which place substantial responsibility on clinical research organizations, consultants and other service providers for the development of our approved product and our product candidates. We also rely on medical and academic institutions to perform aspects of our clinical trials of product candidates. In addition, an element of our research and development strategy has been to in-license technology and product candidates from academic and government institutions in order to minimize investments in early research. We have entered into agreements under which we are now dependent on Ono and Salix for the commercialization and development of Relistor. We may not be able to maintain our relationships with them, or establish new ones for Relistor or other product candidates on beneficial terms. We may not be able to enter new arrangements without undue delays or expenditures, and these arrangements may not allow us to compete successfully. Moreover, if third parties do not successfully carry out their contractual duties, meet expected deadlines or conduct clinical trials in accordance with regulatory requirements or applicable protocols, our product candidates may not be approved for marketing and commercialization or such approval may be delayed. If that occurs, we or our collaborators will not be able, or may be delayed in our efforts, to commercialize our product candidates.

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We lack sales and marketing infrastructure and related staff, which will require significant investment to establish and in the meantime may make us dependent on third parties for their expertise in this area.

We have no established sales, marketing or distribution infrastructure. If we receive marketing approval for a pharmaceutical product, significant investment, time and managerial resources will be required to build the commercial infrastructure required to market, sell and support it. Should we choose to commercialize a product directly, we may not be successful in developing an effective commercial infrastructure or in achieving sufficient market acceptance. Alternatively, we may choose to market and sell products through distribution, co-marketing, co-promotion or licensing arrangements with third parties. We may also consider contracting with a third party professional pharmaceutical detailing and sales organization to perform the marketing function for one or more products. To the extent that we enter into distribution, co-marketing, co-promotion, detailing or licensing arrangements for the marketing and sale of product candidates, any revenues we receive will depend primarily on the efforts of third parties. We will not control the amount and timing of marketing resources these third parties devote to our products.

We are exposed to product liability claims, and in the future may not be able to obtain insurance against claims at a reasonable cost or at all.

Our business exposes us to product liability risks, which are inherent in the testing, manufacturing, marketing and sale of pharmaceutical products. We may not be able to avoid product liability exposure. If a product liability claim is successfully brought against us, our financial position may be adversely affected. Under our license agreement with Salix, we are responsible for product liability claims arising out of clinical trials that were conducted under our supervision. We are indemnified by Salix under our license agreement with Salix for product liability exposure arising from its marketing and sales of Relistor, and maintain our own product liability insurance coverage in the amount of $10.0 million per occurrence, subject to a deductible and a $10.0 million annual aggregate limitation and other clinical trial or other insurance as required by contract and local laws. Pursuant to our transition agreement with Wyeth Pharmaceuticals, we released Wyeth from its indemnification responsibility for product liability exposure arising from its marketing and sales of Relistor. Product liability insurance for the biopharmaceutical industry is generally expensive, when available at all, and may not be available to us at a reasonable cost in the future. Our current insurance coverage and indemnification arrangements may not be adequate to cover claims brought against us, and are in any event subject to the insuring or indemnifying entity discharging its obligations to us.

We handle hazardous materials and must comply with environmental laws and regulations, which can be expensive and restrict how we do business. If we are involved in a hazardous waste spill or other accident, we could be liable for damages, penalties or other forms of censure.

Our research and development work and manufacturing processes involve the use of hazardous, controlled and radioactive materials. We are subject to federal, state and local laws and regulations governing the use, manufacture, storage, handling and disposal of these materials. Despite procedures that we implement for handling and disposing of these materials, we cannot eliminate the risk of accidental contamination or injury. In the event of a hazardous waste spill or other accident, we could be liable for damages, penalties or other forms of censure. We may be required to incur significant costs to comply with environmental laws and regulations in the future.

If we lose key management and scientific personnel on whom we depend, our business could suffer.

We are dependent upon our key management and scientific personnel, the loss of whom could require us to identify and engage qualified replacements, and could cause our management and operations to suffer in the interim. Competition for qualified employees among companies in the biopharmaceutical industry is intense. Future success in our industry depends in significant part on the ability to attract, retain and motivate highly skilled employees, which we may not be successful in doing.

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Heath care reform measures could adversely affect our operating results and our ability to obtain marketing approval of and to commercialize our product candidates.

In the U.S. and some foreign jurisdictions, there have been a number of legislative and regulatory changes and proposed changes regarding the health care system that could prevent or delay marketing approval of our product candidates, restrict or regulate post-approval activities and affect our ability to profitably sell any product candidates for which we obtain marketing approval. Legislative and regulatory proposals have been made to expand post-approval requirements and restrict sales and promotional activities for pharmaceutical products. In addition, increased scrutiny by the U.S. Congress of the FDA's approval process may significantly delay or prevent marketing approval, as well as subject us to more stringent product labeling and post-marketing testing and other requirements. In the U.S., federal legislation has changed the way Medicare covers and pays for pharmaceutical products. Cost reduction initiatives and other provisions of legislation have decreased coverage and reimbursement. Though such legislation applies only to drug benefits for Medicare beneficiaries, private payors often follow Medicare coverage policy and payment limitations in setting their own reimbursement rates. More recent legislation is intended to broaden access to health insurance, further reduce or constrain the growth of healthcare spending, enhance remedies against fraud and abuse, add new transparency requirements for health care and health insurance industries, and impose new taxes and fees on the health industry and additional health policy reforms. New laws impose significant annual fees on companies that manufacture or import branded prescription drug products, and contain substantial new compliance provisions, which in each case may affect our business practices with health care practitioners. Subject to federal and state agencies issuing regulations or guidance, it appears likely that new laws will continue to pressure pharmaceutical pricing, especially under the Medicare program, and may also increase regulatory burdens and operating costs. We cannot be sure whether additional legislative changes will be enacted, whether the FDA regulations, guidance or interpretations will be changed or what the impact of such changes on the marketing approvals of our product candidates, if any, may be.

Our and/or our collaborators' relationships with customers and third-party payors will be subject to applicable anti-kickback, fraud and abuse and other healthcare laws and regulations, which could expose us or them to criminal sanctions, civil penalties, program exclusion, contractual damages, reputational harm and diminished profits and future earnings.

Health care providers, physicians and third-party payors play a primary role in the recommendation and prescription of any product candidates for which we obtain marketing approval. Our or our collaborators future arrangements with third-party payors and customers may expose us or them to broadly applicable fraud and abuse and other health care laws and regulations that may constrain the business or financial arrangements and relationships through which we or our collaborators market, sell and distribute our products that obtain marketing approval. Efforts to ensure that business arrangements comply with applicable health care laws and regulations involve substantial costs. It is possible that governmental authorities will conclude that our or our collaborators' business practices may not comply with current or future statutes, regulations or case law involving applicable fraud and abuse or other healthcare laws and regulations. If such operations are found to be in violation of any of these laws or other applicable governmental regulations, we or the collaborator may be subject to significant civil, criminal and administrative penalties, damages, fines, exclusion from government funded healthcare programs, such as Medicare and Medicaid, and the curtailment or restructuring of related operations. If physicians or other providers or entities involved with our products are found to be not in compliance with applicable laws, they may be subject to criminal, civil or administrative sanctions, including exclusions from government funded healthcare programs, which may adversely affect us.

We cannot rely on federal government grants and research contracts as a continuing source of funds.

Federal government grants and research contracts, in particular from the National Institutes of Health, have in the past generally been available for biotechnology research and development in various areas. Funds available under such grants or contracts, however, must be applied for, if awarded must be used to fund qualifying research and development programs specified in the application, and are subject to adjustment based on the results of periodic audits. The government's obligation to make payments under these grants and/or contracts is subject to appropriation by the U.S. Congress for funding in each year, which is subject to changes due to budgetary constraints, policy changes and other factors. While we have been awarded such grants and contracts in the past, we do not currently have significant funding from such sources, and in any event cannot rely on them as a continuing source of funds.

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Our future depends on the proper management of our current and future business operations, including those of Molecular Insight, and their associated expenses.

Our business strategy requires us to manage our business to provide for the continued development and potential commercialization of our proprietary and partnered product candidates. Our strategy also calls for us to undertake increased research and development activities and to manage an increasing number of relationships with partners and other third parties, while simultaneously managing the capital necessary to support this strategy. These tasks are significantly increased as a result of our acquisition of Molecular Insight. If we are unable to manage effectively our current operations and any growth we may experience, our business, financial condition and results of operations may be adversely affected. If we are unable to effectively manage our expenses, we may find it necessary to reduce our personnel-related costs through reductions in our workforce, which could harm our operations, employee morale and impair our ability to retain and recruit talent. Furthermore, if adequate funds are not available, we may be required to obtain funds through arrangements with partners or other sources that may require us to relinquish rights to certain of our technologies, products or future economic rights that we would not otherwise relinquish or require us to enter into other financing arrangements on unfavorable terms.

Progenics has a history of operating losses, as does Molecular Insight, which has also been reorganized under the U.S. Bankruptcy Code.

Progenics has incurred substantial losses throughout its history. A large portion of our revenue has historically consisted of upfront and milestone from licensing transactions. We reported an operating loss for 2012 and while we reported operating income for 2011, as a result of a one-time upfront payment from Salix, the timing and amount of any similar transactions in the future is highly unpredictable and uncertain. Without upfront or other such payments, we operate at a loss, due in large part to the significant research and development expenditures required to identify and validate new product candidates and pursue our development efforts. Moreover, we have derived no significant revenue from product sales and have only in the last several years derived revenue from royalties. We may not achieve significant product sales or royalty revenue for a number of years, if ever. We expect to incur net operating losses and negative cash flow from operations in the future, which could increase significantly if we expand our clinical trial programs and other product development efforts, including those attendant to the product candidates and programs we have acquired in the Molecular Insight transaction. Our ability to achieve and sustain profitability is dependent in part on obtaining regulatory approval for and then commercializing our product candidates, either alone or with others. We may not be able to develop and commercialize products beyond subcutaneous Relistor. Our operations may not be profitable even if any of our other product candidates under development are commercialized.

Molecular Insight has incurred net losses every year from its inception in 1997 and generated no significant revenue from product sales and only limited revenue from licenses. In December, 2010, Molecular Insight filed a voluntary petition in the United States Bankruptcy Court for the District of Massachusetts seeking relief under the provisions of Chapter 11 of the U.S. Bankruptcy Code (Case No. 10-23355). It operated its business and managed its properties as a debtor in possession under bankruptcy protection until emerging from bankruptcy in May, 2011.

Progenics' stock price has a history of volatility and may be affected by selling pressure, including in the event of substantial sales of Progenics stock by former Molecular Insight stockholders. You should consider an investment in Progenics stock as risky and invest only if you can withstand a significant loss.

Our stock price has a history of significant volatility. In 2012, it varied between a high of $11.34 and a low of $1.41. Factors that may have a significant impact on the market price of our common stock include the results of clinical trials and pre-clinical studies undertaken by us or others; delays, terminations or other changes in development programs; developments in marketing approval efforts, such as the FDA's July, 2012 Complete Response Letter with respect to the sNDA for Relistor subcutaneous injection for the treatment of OIC in adult patients with chronic, non-cancer pain; developments in collaborator or other business relationships, particularly regarding Relistor, PSMA ADC or other significant products or programs; technological innovation or product announcements by us, our collaborators or our competitors; patent or other proprietary rights developments; governmental regulation; changes in reimbursement policies or health care legislation; safety and efficacy concerns about products developed by us, our collaborators or our competitors; our ability to fund ongoing operations; fluctuations in our operating results; purchases we may make under a share repurchase program, or discontinuation of any such purchases; and general market conditions. At times, our stock price has been volatile even in the absence of significant news or developments. The stock prices of biotechnology companies and securities markets generally have been subject to dramatic price swings in recent years, and financial and market conditions during that period have resulted in widespread pressures on securities of issuers throughout the world economy.

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Sales of substantial numbers of shares of common stock, including sales by former Molecular Insight stockholders of unregistered Progenics shares they received in the acquisition, could cause a decline in the market price of our stock. We require substantial external funding to finance our research and development programs and may seek such funding through the issuance and sale of our common stock, such as our 2012 follow-on underwritten public offering. We have in place a shelf registration statement which we accessed for that offering and which may be used for additional issuances of common stock, preferred stock, debt securities, warrants and other rights units to investors. We also have in place and utilize registration statements registering shares issuable pursuant to our equity compensation plans. Sales of our securities pursuant to these registration statements could cause the market price of our stock to decline. Any sales by existing stockholders or holders of options, or other rights, may have an adverse effect on our ability to raise capital and may adversely affect the market price of our common stock.

Our principal stockholders are able to exert significant influence over matters submitted to stockholders for approval.

At 2012 year end, our directors and executive officers together beneficially owned or controlled approximately nine percent of our outstanding common shares, and our five largest other stockholders over half. Should these parties choose to act together, they could exert significant influence in determining the outcome of corporate actions requiring stockholder approval and otherwise control our business. This control could, among other things, have the effect of delaying or preventing a change in control of the Company, adversely affecting our stock price.

Anti-takeover provisions may make removal of our Board and/or management more difficult, discouraging hostile bids for control that may be beneficial to our stockholders.

Our Board is authorized, without further stockholder action, to issue from time to time shares of preferred stock in one or more designated series or classes. The issuance of preferred stock, as well as provisions in some outstanding stock options that provide for acceleration of exercisability upon a change of control, and Section 203 and other provisions of the Delaware General Corporation Law could make a takeover or the removal of our Board or management more difficult; discourage hostile bids for control in which stockholders may receive a premium for their shares; and otherwise dilute the rights of common stockholders and depress the market price of our stock.

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PART IV

Item 15. Exhibits, Financial Statement Schedules

The following documents or the portions thereof indicated are filed as a part of this Report.

(c)

Item 601 Exhibits:

Those exhibits required to be filed by Item 601 of Regulation S-K are listed in the Exhibit Index immediately following the signature page hereof and preceding the exhibits filed herewith, which is incorporated herein by this reference.

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SIGNATURES

Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned, hereunto duly authorized.

	PROGENICS PHARMACEUTICALS, INC.
	By:	/s/ ANGELO W. LOVALLO, JR.
		Angelo W. Lovallo, Jr. (Duly authorized officer of the Registrant and Vice President, Finance and Treasurer (Principal Financial Officer))

Date: January 17, 2014

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EXHIBIT INDEX

Exhibit
Number *			Description
3.1(1)			Amended and Restated Certificate of Incorporation of the Registrant.
3.2(2)			Amended and Restated By-laws of the Registrant.
4.1(3)			Specimen Certificate for Common Stock, $0.0013 par value per share, of the Registrant.
10.1(3)			Form of Registration Rights Agreement.
10.2(3)			1989 Non-Qualified Stock Option Plan‡
10.3(3)			1993 Stock Option Plan, as amended‡
10.4(3)			1993 Executive Stock Option Plan‡
10.5(4)			Amended and Restated 1996 Stock Incentive Plan‡
10.6.3(5)			Amended 2005 Stock Incentive Plan ‡
10.6.4(6)			Form of Non-Qualified Stock Option Award Agreement ‡
10.6.5(6)			Form of Restricted Stock Award Agreement ‡
10.7(7)			Form of Indemnification Agreement‡
10.8(8)			Employment Agreement, dated December 31, 2007, between the Registrant and Dr. Paul J. Maddon‡
10.8.1(9)			First Amendment to Employment Agreement, dated March 31, 2011, between the Registrant and Dr. Paul J. Maddon‡
10.8.2(10)			Retirement Agreement, dated as of March 14, 2012, between the Registrant and Dr. Paul J. Maddon‡
10.9(3)			Letter dated August 25, 1994 between the Registrant and Dr. Robert J. Israel‡
10.16(11)†			Development and License Agreement, dated April 30, 1999, between Protein Design Labs, Inc. and the Registrant.
10.16.1(12)			Letter Agreement, dated November 24, 2003, relating to the Development and License Agreement between Protein Design Labs, Inc. and the Registrant.
10.18(13)			Director Stock Option Plan‡
10.19(14)†			Exclusive Sublicense Agreement, dated September 21, 2001, between the Registrant and UR Labs, Inc.
10.19.1(15)			Amendment to Exclusive Sublicense Agreement, dated September 21, 2001, between the Registrant and UR Labs, Inc.
10.21.1(16)			Amended and Restated Agreement of Lease, dated October 28, 2009, between BMR-Landmark at Eastview LLC and the Registrant.
10.23			Information concerning compensation of the Registrant's non-employee directors is included in the Registrant's proxy material for its 2012 Annual Meeting of Stockholders and is incorporated herein by reference.‡
10.25(17) †			Option and License Agreement, dated May 8, 1985, by and between the University of Chicago and UR Labs, Inc., as amended by (i) Amendment to Option and License Agreement, dated September 17, 1987, by and between the University of Chicago and UR Labs, Inc., (ii) Second Amendment to Option and License Agreement, dated March 3, 1989, by and among the University of Chicago, ARCH Development Corporation and UR Labs, Inc., and (iii) Letter Agreement Related to Progenics' Relistor In-License dated, December 22, 2005, by and among the University of Chicago, acting on behalf of itself and ARCH Development Corporation, the Registrant, Progenics Pharmaceuticals Nevada, Inc. and Wyeth, acting through its Wyeth Pharmaceuticals Division.
10.26(18)			Membership Interest Purchase Agreement, dated April 20, 2006, between the Registrant Inc. and Cytogen Corporation.
10.27(18) †			Amended and Restated PSMA/PSMP License Agreement, dated April 20, 2006, by and among the Registrant, Cytogen Corporation and PSMA Development Company LLC.
10.28(19)			Consulting Agreement, dated May 1, 1995, between Active Biotherapies, Inc. and Dr. David A. Scheinberg, M.D., Ph.D., as amended on June 13, 1995, as assigned to the Registrant, and as amended on January 1, 2001‡
10.29(20) †			License Agreement, dated as of October 16, 2008, by and among Ono Pharmaceutical Co., Ltd. and the Registrant.
10.30(20) †			Partial Termination and License Agreement, dated October 16, 2008, by and among Wyeth, acting through Wyeth Pharmaceuticals Division, Wyeth-Whitehall Pharmaceuticals, Inc. and Wyeth-Ayerst Lederle, Inc. and the Registrant and Progenics Pharmaceuticals Nevada, Inc.
10.31(20) †			Consent, Acknowledgment and Agreement, dated as of October 16, 2008, by and among Wyeth, acting through Wyeth Pharmaceuticals Division, Wyeth-Whitehall Pharmaceuticals, Inc. and Wyeth-Ayerst Lederle, Inc., the Registrant and Ono Pharmaceutical Co., Ltd.

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10.32(20) †								2008 Agreement Related to Progenics' MNTX In-License, dated October 16, 2008, by and among the University of Chicago, acting on behalf of itself and ARCH Development Corporation, the Registrant, Progenics Pharmaceuticals Nevada, Inc. and Ono Pharmaceutical Co., Ltd.
10.33(21) †								Termination and Transition Agreement, effective as of October 1, 2009, by and among Wyeth, acting through Wyeth Pharmaceuticals Division, Wyeth-Whitehall Pharmaceuticals, Inc., Wyeth-Ayerst Lederle, Inc., and AHP Manufacturing B.V., and the Registrant, Progenics Pharmaceuticals Nevada, Inc. and Excelsior Life Sciences Ireland Limited.
10.33.1(22) †								First Amendment to Termination and Transition Agreement, effective as of October 1, 2010, by and among Wyeth LLC, acting through Wyeth Pharmaceuticals Division, Wyeth-Whitehall Pharmaceuticals LLC, Wyeth-Ayerst Lederle LLC, and AHP Manufacturing B.V., and the Registrant, Progenics Pharmaceuticals Nevada, Inc. and Excelsior Life Sciences Ireland Limited.
10.34(23) †								Collaboration Agreement, effective June 14, 2005, by and between Seattle Genetics, Inc. and PSMA Development Company, LLC.
10.37(9) †								License Agreement dated as of February 3, 2011, by and between Salix Pharmaceuticals, Inc., the Registrant, Progenics Pharmaceuticals Nevada, Inc. and Excelsior Life Sciences Ireland Limited.
10.37.1(9) †								2010 Agreement Related to Progenics' MNTX In-License, dated February 3, 2011, by and among the University of Chicago, acting on behalf of itself and ARCH Development Corporation, the Registrant, Progenics Pharmaceuticals Nevada, Inc. and Salix Pharmaceuticals, Inc.
12.1								Statement re computation of ratio of earnings (loss) to combined fixed charges and preferred stock dividends.
21.1								Subsidiaries of the Registrant.
23.1								Consent of PricewaterhouseCoopers LLP.
23.2								Consent of Ernst & Young LLP.
31.1								Certification of Mark R. Baker, Chief Executive Officer of the Registrant pursuant to 13a-14(a) and Rule 15d-14(a) under the Securities Exchange Act of 1934, as amended.
31.2								Certification of Angelo W. Lovallo, Jr., Senior Executive Director, Financial Reporting & Treasurer of the Registrant pursuant to 13a-14(a) and Rule 15d-14(a) under the Securities Exchange Act of 1934, as amended.
31.3								Certification of Mark R. Baker, Chief Executive Officer of the Registrant pursuant to 13a-14(a) and Rule 15d-14(a) under the Securities Exchange Act of 1934, as amended.
31.4								Certification of Angelo W. Lovallo, Jr., Vice President, Finance & Treasurer of the Registrant pursuant to 13a-14(a) and Rule 15d-14(a) under the Securities Exchange Act of 1934, as amended.
31.5**								Certification of Mark R. Baker, Chief Executive Officer of the Registrant pursuant to 13a-14(a) and Rule 15d-14(a) under the Securities Exchange Act of 1934, as amended.
31.6**								Certification of Angelo W. Lovallo, Jr., Vice President, Finance & Treasurer of the Registrant pursuant to 13a-14(a) and Rule 15d-14(a) under the Securities Exchange Act of 1934, as amended.
32.1								Certification of Mark R. Baker, Chief Executive Officer of the Registrant pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.
32.2								Certification of Angelo W. Lovallo, Jr., Senior Executive Director, Financial Reporting & Treasurer of the Registrant pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.
32.3								Certification of Mark R. Baker, Chief Executive Officer of the Registrant pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.
32.4								Certification of Angelo W. Lovallo, Jr., Vice President, Finance and Treasurer (Principal Financial and Accounting Officer) of the Registrant pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.
32.5**								Certification of Mark R. Baker, Chief Executive Officer of the Registrant pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.
32.6**								Certification of Angelo W. Lovallo, Jr., Vice President, Finance and Treasurer (Principal Financial and Accounting Officer) of the Registrant pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.
101								Interactive Data File
101.INS								XBRL Instance Document
101.SCH								XBRL Taxonomy Extension Schema
101.CAL								XBRL Taxonomy Extension Calculation Linkbase
101.LAB								XBRL Taxonomy Extension Label Linkbase
101.PRE								XBRL Taxonomy Extension Presentation Linkbase
101.DEF								XBRL Taxonomy Extension Definition Document

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*		Exhibits footnoted as previously filed have been filed as an exhibit to the document of the Registrant referenced in the footnote below, and are incorporated by reference herein. Exhibits not so footnoted and not filed herewith were filed with the Registrant's Annual Report on Form 10-K for the year ended December 31, 2012 filed with the SEC March 15, 2012, or in the case of Exhibits 31.3, 31.4, 32.3 and 32.4, with the Registrant's Amendment No. 1 on Form 10-K/A filed April 30, 2013.

**		Filed herewith.

(1)		Previously filed in Quarterly Report on Form 10-Q for the quarter ended June 30, 2011.
(2)		Previously filed in Current Report on Form 8-K filed on March 16, 2012.
(3)		Previously filed in Registration Statement on Form S-1, Commission File No. 333-13627.
(4)		Previously filed in Registration Statement on Form S-8, Commission File No. 333-120508.
(5)		Previously filed in Current Report on Form 8-K filed on November 28, 2012.
(6)		Previously filed in Current Report on Form 8-K filed on July 8, 2008.
(7)		Previously filed in Quarterly Report on Form 10-Q for the quarterly period ending March 31, 2007
(8)		Previously filed in Annual Report on Form 10-K for the year ended December 31, 2007.
(9)		Previously filed in Quarterly Report on Form 10-Q for the quarter ended March 31, 2011.
(10)		Previously filed in Quarterly Report on Form 10-Q for the quarter ended March 31, 2012.
(11)		Previously filed in Quarterly Report on Form 10-Q for the quarterly period ended June 30, 1999.
(12)		Previously filed in Annual Report on Form 10-K for the year ended December 31, 2004.
(13)		Previously filed in Annual Report on Form 10-K for the year ended December 31, 1999.
(14)		Previously filed in Annual Report on Form 10-K for the year ended December 31, 2002.
(15)		Previously filed in Current Report on Form 8-K filed on September 20, 2004.
(16)		Previously filed in Current Report on Form 8-K filed on November 28, 2012.
(17)		Previously filed in Annual Report on Form 10-K for the year ended December 31, 2005.
(18)		Previously filed in Quarterly Report on Form 10-Q for the quarterly period ending June 30, 2006.
(19)		Previously filed in Annual Report on Form 10-K/A for the year ended December 31, 2006.
(20)		Previously filed in Annual Report on Form 10-K for the year ended December 31, 2008.
(21)		Previously filed in Annual Report on Form 10-K for the year ended December 31, 2009.
(22)		Previously filed in Annual Report on Form 10-K for the year ended December 31, 2010.
(23)		Previously filed in Amendment No. 2 to Annual Report on Form 10-K/A for the year ended December 31, 2009.


†		Confidential treatment granted as to certain portions omitted and filed separately with the Commission.
‡		Management contract or compensatory plan or arrangement.