schedule13d_a2.htm
UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
 
SCHEDULE 13D
 
Under the Securities Exchange Act of 1934
 
(Amendment No. 2)*

AMAG Pharmaceuticals, Inc.

(Name of Issuer)

Common Stock, par value $0.01 per share

(Title of Class of Securities)

00163U106

(CUSIP Number)

Paul S. Scrivano, Esq.
O’Melveny & Myers LLP
Times Square Tower
7 Times Square
New York, New York 10036
(212) 326-2000

(Name, Address and Telephone Number of Person
Authorized to Receive Notices and Communications)

December 22, 2010

(Date of Event Which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of sections 240.13d-1(e), 240.13d-1(f) or 140.13d-1(g), check the following box.  [ X ]
 
Note:  Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits.  See section 240.13d-7 for other parties to whom copies are to be sent.
 
* The remainder of this cover page shall be filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter the disclosures provided in a prior cover page.
 
The information required in the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).
 
Page 1of 7
 
 
1.
Names of Reporting Persons

 
Palo Alto Investors, Inc.
 
 
2.
Check the Appropriate Box if a Member of a Group (See Instructions)
 
 
  (a)
 
 
 
  (b)
  X
 
 
3.
SEC Use Only
  
 
 
4.
Source of Funds (See Instructions) 
AF
 
 
5.
Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e) ____
 
 
6.
  Citizenship or Place of Organization 
California

Number of
Shares
Beneficially
Owned by
Each Reporting
Person With
7.           Sole Voting Power                                                               0
8.           Shared Voting Power                                                      2,547,739
9.           Sole Dispositive Power                                                      0
10.           Shared Dispositive Power                                           2,547,739

 
11.
Aggregate Amount Beneficially Owned by Each Reporting Person 
2,547,739
 
 
12.
Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions)

 
13.
Percent of Class Represented by Amount in Row (11) 
12.1%
 
 
14.
Type of Reporting Person (See Instructions) 
CO, HC
 
 
Page 2of 7
 
 
1.
Names of Reporting Persons

 
Palo Alto Investors, LLC
 
 
2.
Check the Appropriate Box if a Member of a Group (See Instructions)
 
 
   (a)
 
 
 
   (b)
 X
 
 
3.
SEC Use Only
  
 
 
4.
Source of Funds (See Instructions) 
AF
 
 
5.
Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e) ______
 
 
6.
Citizenship or Place of Organization 
California

Number of
Shares
Beneficially
Owned by
Each Reporting
Person With
7.           Sole Voting Power                                                              0
8.           Shared Voting Power                                                      2,547,739
9.           Sole Dispositive Power                                                      0
10.           Shared Dispositive Power                                           2,547,739

 
11.
Aggregate Amount Beneficially Owned by Each Reporting Person 
2,547,739
 
 
12.
Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions)
 
 
13.
Percent of Class Represented by Amount in Row (11) 
12.1%
 
 
14.
Type of Reporting Person (See Instructions) 
IA, OO
 
 
Page 3of 7
 
 
1.
Names of Reporting Persons

 
William Leland Edwards
 
 
2.
Check the Appropriate Box if a Member of a Group (See Instructions)
 
 
   (a)
 
 
 
   (b)
X
 
 
3.
SEC Use Only
  
 
 
4.
Source of Funds (See Instructions) 
AF
 
 
5.
Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e) ____ 
 
 
6.
Citizenship or Place of Organization 
U.S.A.

Number of
Shares
Beneficially
Owned by
Each Reporting
Person With
7.           Sole Voting Power                                                              4,700
8.           Shared Voting Power                                                      2,547,739
9.           Sole Dispositive Power                                                      4,700
10.           Shared Dispositive Power                                           2,547,739

 
11.
Aggregate Amount Beneficially Owned by Each Reporting Person 
2,552,439
 
 
12.
Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions)
 
 
13.
Percent of Class Represented by Amount in Row (11) 
12.1%
 
 
14.
Type of Reporting Person (See Instructions) 
IN, HC

 
 
Page 4of 7
 
 
1.
Names of Reporting Persons

 
Anthony Joonkyoo Yun, MD
 
 
2.
Check the Appropriate Box if a Member of a Group (See Instructions)
 
 
   (a)
 
 
 
   (b)
 X
 
 
3.
SEC Use Only
  
 
 
4.
Source of Funds (See Instructions) 
AF

 
5.
Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e) ____
 
 
6.
Citizenship or Place of Organization 
U.S.A.

Number of
Shares
Beneficially
Owned by
Each Reporting
Person With
7.           Sole Voting Power                                                              0
8.           Shared Voting Power                                                      2,547,739
9.           Sole Dispositive Power                                                      0
10.           Shared Dispositive Power                                           2,547,739

 
11.
Aggregate Amount Beneficially Owned by Each Reporting Person 
2,547,739
 
 
12.
Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions)
 
 
13.
Percent of Class Represented by Amount in Row (11) 
12.1%
 
 
14.
Type of Reporting Person (See Instructions) 
IN, HC
 
 
 
Page 5of 7
 
 
This Amendment No. 2 (this “Amendment No. 2”) amends and supplements the Schedule 13D originally filed with the Securities and Exchange Commission (the “SEC”) on November 22, 2010 (the “Original Statement”), as amended by Amendment No. 1 filed with the SEC on December 9, 2010 (the Original Statement and such amendment, together with this Amendment No. 2, are collectively referred to herein as the “Statement”), by William Leland Edwards, Palo Alto Investors, LLC (“PAI LLC”), Palo Alto Investors, Inc. (“PAI Corp”), and Anthony Joonkyoo Yun, MD (collectively, the “Filers”).  Except as set forth in this Amendment No. 2, all information set forth in the Statement remains unchanged and capitalized terms used but not defined in this Amendment No. 2 shall have the meanings ascribed to such terms in the Original Statement.

Item 3.                      Source and Amount of Funds or Other Consideration
 
Item 3 is amended and restated in its entirety to read as follows:
 
The source and amount of funds used in purchasing the Stock were as follows:
 
Purchaser
Source of Funds
Amount
PAI LLC
Funds Under Management
$75,31,251


Item 5.                      Interest in Securities of the Issuer
 
Item 5(c) is amended and supplemented to add the following at the end thereof:
 
Person Effecting Transaction
Date
Purchase or Sale
 Quantity
 Price per Share
PAI LLC   12/8/2010                             purchase 19,500   $15.77
PAI LLC
12/9/2010
purchase
                   19,700
                        $15.96
PAI LLC
12/10/2010
purchase
                    11,500
                          $16.45
PAI LLC
12/13/2010
purchase
                    18,900
                         $16.23
PAI LLC
12/14/2010
purchase
                    13,700
                          $16.25
PAI LLC
12/15/2010
purchase
                    15,000
                         $16.37
PAI LLC
12/16/2010
purchase
                      7,900
                          $16.61
PAI LLC
12/17/2010
purchase
                    25,000
                          $17.44
PAI LLC
12/20/2010
purchase
                    23,600
                          $17.33
PAI LLC
12/21/2010
purchase
                    75,800
                          $17.72
PAI LLC
12/22/2010
purchase
                    97,700
 $18.07
PAILLC  12/23/2010                         purchase 50,000 $17.76
 
 
Page 6of 7
 
SIGNATURES

After reasonable inquiry and to the best of my knowledge, I certify that the information set forth in this statement is true, complete and correct.

Dated:              December 23, 2010

PALO ALTO INVESTORS, INC.
 
 
By:           /s/ Mark Shamia                                           
Mark Shamia, Chief Operating Officer
 
PALO ALTO INVESTORS, LLC
 
 
By:           /s/ Mark Shamia                                           
Mark Shamia, Chief Operating Officer
 
/s/ Anthony Joonkyoo Yun                                                      
Anthony Joonkyoo Yun, MD
 
/s/ William Leland Edwards                                                      
William Leland Edwards