13G Filing: Billionaire David Shaw’s D. E. Shaw & Co. and AMAG Pharmaceuticals Inc. (AMAG)

Page 4 of 6 SEC Filing

Item 1.
(a) Name of Issuer
AMAG Pharmaceuticals, Inc.
(b) Address of Issuer’s Principal Executive Offices
1100 Winter Street
Waltham, Massachusetts 02451
Item 2.
(a) Name of Person Filing
D. E. Shaw & Co., L.P.
David E. Shaw
(b) Address of Principal Business Office or, if none, Residence
The business address for each reporting person is:
1166 Avenue of the Americas, 9th Floor
New York, NY 10036
(c) Citizenship
D. E. Shaw & Co., L.P. is a limited partnership organized under the laws of the state of Delaware.
David E. Shaw is a citizen of the United States of America.
(d) Title of Class of Securities
Common Stock, par value $0.01
(e) CUSIP Number
00163U106
Item 3. If this statement is filed pursuant to Rule 13d-1(b) or 13d-2(b) or (c), check whether the person filing is a:
Not Applicable
Item 4. Ownership

As of January 4, 2016:

(a) Amount beneficially owned:

D. E. Shaw & Co., L.P.:

1,735,509 shares

This is composed of (i) 1,051,098 shares in the name of D. E. Shaw
Valence Portfolios, L.L.C., (ii) 597,677 shares in the name of D. E. Shaw Oculus Portfolios, L.L.C., (iii) 1,500 shares in the
name of D. E. Shaw Heliant Capital, L.L.C., and (iv) 85,234 shares under the management of D. E. Shaw Investment Management,
L.L.C.

David E. Shaw:

1,735,509 shares

This is composed of (i) 1,051,098 shares in the name of D. E. Shaw
Valence Portfolios, L.L.C., (ii) 597,677 shares in the name of D. E. Shaw Oculus Portfolios, L.L.C., (iii) 1,500 shares in the
name of D. E. Shaw Heliant Capital, L.L.C., and (iv) 85,234 shares under the management of D. E. Shaw Investment Management,
L.L.C.

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