SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of report (Date of earliest event reported): April 5, 2002 REPLIGEN CORPORATION (Exact Name of Registrant as Specified in its Charter) DELAWARE 000-14656 04-2729386 (State or Other Jurisdiction of Commission (I.R.S. Employer Incorporation) File Number) Identification No.) 117 Fourth Avenue, Needham, Massachusetts 02494 (Address of principal executive offices) (Zip Code) Registrant's telephone number, including area code: (781) 449-9560 No change since last report (Former Name or Former Address, if Changed Since Last Report) Item 5. Other Events. On April 5, 2002, Repligen Corporation announced that the United States Food and Drug Administration (FDA) has granted approval to market SecreFlo(TM) (synthetic porcine secretin), the first synthetic version of the hormone secretin. SecreFlo(TM) has been approved for stimulation of pancreatic secretions. Item 7. Financial Statements, Pro Forma Financial Information and Exhibits. (a) Financial Statements of Business Acquired: None required. (b) Pro Forma Financial Information: None required. (c) Exhibits: Exhibit No. Description ----------- ----------- 99.1 Press release of the Company dated April 5, 2002. SIGNATURE Pursuant to the requirements 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. REPLIGEN CORPORATION By: /s/ Walter C. Herlihy ------------------------- Name: Walter C. Herlihy Title: President and Chief Executive Officer Date: April 9, 2002 -2- EXHIBIT INDEX Exhibit No. Description ----------- ----------- 99.1 Press release of the Company dated April 5, 2002. -3-