FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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(Print or Type Responses)

1. Name and Address of Reporting Person *   DENNER ALEXANDER J 2. Date of Event Requiring Statement (Month/Day/Year) 02/02/2016 3. Issuer Name and Ticker or Trading Symbol MEDICINES CO /DE [MDCO] (Last) (First) (Middle) C/O SARISSA CAPITAL MANAGEMENT LP, 660 STEAMBOAT ROAD 4. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director _____ 10% Owner _____ Officer (give title below) _____ Other (specify below) 5. If Amendment, Date Original Filed(Month/Day/Year) (Street) GREENWICH, CT 06830 6. Individual or Joint/Group Filing(Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Beneficially Owned

1.Title of Security (Instr. 4) 2. Amount of Securities Beneficially Owned (Instr. 4) 3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5) 4. Nature of Indirect Beneficial Ownership (Instr. 5) Common Stock 658,595 I Sarissa Capital Offshore Master Fund LP (1) (2) Common Stock 1,093,405 I Sarissa Capital Domestic Fund LP (1) (3)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.			SEC 1473 (7-02)
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Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
DENNER ALEXANDER J C/O SARISSA CAPITAL MANAGEMENT LP 660 STEAMBOAT ROAD GREENWICH, CT 06830	  X	Â	Â	Â

Signatures

/s/ Alexander J. Denner, Ph.D.		02/04/2016
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 5(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	The reporting person is the founding partner and Chief Investment Officer of Sarissa Capital Management L.P., investment advisor to this fund. As such and due to the positions set forth in footnotes (2) and (3), the reporting person may be deemed to beneficially own the securities owned by this fund. The reporting person disclaims any beneficial ownership of these securities, except to the extent of his pecuniary interest therein.
(2)	The reporting person is a partner of Sarissa Capital Fund GP LP, the sole member of the general partner of this fund.
(3)	The reporting person holds limited partnership interests in this fund and is a partner of Sarissa Capital Fund GP LP, the general partner of this fund.

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