Ownership Submission
FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN 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 *
ADAGE CAPITAL PARTNERS GP LLC
  2. Issuer Name and Ticker or Trading Symbol
AMAG PHARMACEUTICALS INC. [AMAG]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director __X__ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
(Last)
(First)
(Middle)
200 CLARENDON STREET, 52ND FLOOR
3. Date of Earliest Transaction (Month/Day/Year)
03/04/2009
(Street)

BOSTON, MA 02116
4. If Amendment, Date Original Filed(Month/Day/Year)
6. Individual or Joint/Group Filing(Check Applicable Line)
___ Form filed by One Reporting Person
_X_ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)
2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)
4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)
5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)
6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)
7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Common Stock, par value $.01 per share ("Common Stock") 03/04/2009   P   133,061 A $ 26.6356 2,047,184 I See Footnote (2)
Common Stock 03/05/2009   J/K(1)   100,000 D $ 24.75 1,947,184 I See Footnote (2)
Common Stock 03/05/2009   X/K(1)   100,000 A $ 34.839 2,047,184 I See Footnote (2)
Common Stock 03/05/2009   J/K(1)   477,324 D $ 24.75 1,569,860 I See Footnote (2)
Common Stock 03/05/2009   X/K(1)   477,324 A $ 45.2099 2,047,184 I See Footnote (2)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)
2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)
5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)
6. Date Exercisable and Expiration Date
(Month/Day/Year)
7. Title and Amount of Underlying Securities
(Instr. 3 and 4)
8. Price of Derivative Security
(Instr. 5)
9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)
10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)
11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
Equity Swap (obligation to buy) (1) $ 24.75 03/05/2009   X/K     1 12/08/2008 06/09/2009 Common Stock 100,000 $ 0 0 I See Footnote (2)
Equity Swap (obligation to buy) (1) $ 24.75 03/05/2009   J/K(3)   1   03/05/2009 12/11/2009 Common Stock 100,000 $ 0 1 I See Footnote (2)
Equity Swap (obligation to buy) (1) $ 24.75 03/05/2009   X/K     1 12/08/2008 06/09/2009 Common Stock 477,324 $ 0 0 I See Footnote (2)
Equity Swap (obligation to buy) (1) $ 24.75 03/05/2009   J/K(4)   1   03/05/2009 12/11/2009 Common Stock 477,324 $ 0 1 I See Footnote (2)

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
ADAGE CAPITAL PARTNERS GP LLC
200 CLARENDON STREET
52ND FLOOR
BOSTON, MA 02116
    X    
ADAGE CAPITAL PARTNERS LP
200 CLARENDON STREET
52ND FLOOR
BOSTON, MA 02116
    X    
Adage Capital Advisors, L.L.C.
200 CLARENDON STREET
52ND FLOOR
BOSTON, MA 02116
    X    
Atchinson Robert
200 CLARENDON STREET
52ND FLOOR
BOSTON, MA 02116
    X    
Gross Phillip
200 CLARENDON STREET
52ND FLOOR
BOSTON, MA 02116
    X    

Signatures

 /s/ Adage Capital Partners GP, L.L.C.; By its managing member Adage Capital Advisors, L.L.C.; By its managing member Robert Atchinson   03/06/2009
**Signature of Reporting Person Date

 /s/ Adage Capital Partners, L.P.; By its general partner Adage Capital Partners GP, L.L.C.; By its managing member Adage Capital Advisors, L.L.C.; By its managing member Robert Atchinson   03/06/2009
**Signature of Reporting Person Date

 /s/ Adage Capital Advisors, L.L.C.; By its managing member Robert Atchinson   03/06/2009
**Signature of Reporting Person Date

 /s/ Robert Atchinson   03/06/2009
**Signature of Reporting Person Date

 /s/ Phillip Gross   03/06/2009
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(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 equity swap was settled pursuant to its terms based on the volume weighted average price of the Common Stock of the Issuer on the Transaction Date. The price pursuant to Rule 16b-6(c)(2) is set forth in Column 4 of Table I and Column 2 of Table II. The settlement of the equity swap and the reported purchase of Common Stock in connection therewith are exempt from Section 16(b) of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), pursuant to Rule 16b-6(b) thereunder.
(2) Adage Capital Partners GP, L.L.C., a Delaware limited liability company ("ACPGP"), serves as the general partner of Adage Capital Partners, L.P., a Delaware limited partnership (the "Fund"), and as such has discretion over the portfolio securities beneficially owned by the Fund. Adage Capital Advisors, L.L.C., a Delaware limited liability company ("ACA"), is the managing member of ACPGP and directs ACPGP's operations. Robert Atchinson and Phillip Gross are the managing members of ACPGP and ACA and general partners of the Fund. ACPGP, ACA, Robert Atchinson and Phillip Gross disclaim beneficial ownership of the reported securities except to the extent of their pecuniary interest therein.
(3) On March 5, 2009, the Fund entered into an equity swap agreement with a securities broker under which, upon expiration of the term of the agreement, (i) the Fund will be obligated to pay the broker $24.75 per share for each share of Common Stock that is subject to the agreement, and (ii) the broker will be obligated to pay the Fund the market price of 100,000 shares of Common Stock, as of the end of such term.
(4) On March 5, 2009, the Fund entered into an equity swap agreement with a securities broker under which, upon expiration of the term of the agreement, (i) the Fund will be obligated to pay the broker $24.75 per share for each share of Common Stock that is subject to the agreement, and (ii) the broker will be obligated to pay the Fund the market price of 477,324 shares of Common Stock, as of the end of such term.

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