- Initial Statement of Beneficial Ownership (3)

FORM 3	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES	OMB APPROVAL OMB Number: 3235-0104 Expires: February 28, 2011 Estimated average burden hours per response... 0.5
	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

1. Name and Address of Reporting Person * Astellas Pharma Inc.	2. Date of Event Requiring Statement (MM/DD/YYYY) 6/3/2010	3. Issuer Name and Ticker or Trading Symbol OSI PHARMACEUTICALS INC [OSIP]
(Last)        (First)        (Middle) 3-11, NIHONBASHI-HONCHO, 2-CHOME, CHUO-KU	4. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director                            ___ X ___ 10% Owner _____ Officer (give title below)          _____ Other (specify below)
(Street) TOKYO, M0 103-8411        (City)              (State)              (Zip)	5. If Amendment, Date Original Filed (MM/DD/YYYY)	6. Individual or Joint/Group Filing (Check Applicable Line) ___ Form filed by One Reporting Person _ X _ Form filed by More than One Reporting Person

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, par value $0.01 per share	49669036	I	See footnotes   (1) (2)

Table II - Derivative Securities Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities)
1. Title of Derivate Security (Instr. 4)	2. Date Exercisable and Expiration Date (MM/DD/YYYY)		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

Explanation of Responses:
( 1)	Astellas Pharma Inc. ("Astellas"), Astellas US Holding, Inc., a wholly-owned subsidiary of Astellas ("AUSH"), Ruby Acquisition, Inc., a wholly-owned subsidiary of AUSH ("Purchaser") and OSI Pharmaceuticals, Inc. (the "Issuer"), entered into an Agreement and Plan of Merger, dated as of May 16, 2010, pursuant to which Purchaser conducted a cash tender offer (the "Offer") to purchase all outstanding shares (the "Shares") of common stock, par value $0.01 per Share, of the Issuer, at a price of $57.50 per Share, net to the seller in cash, and subject to the terms and conditions set forth in the Offer to Purchase, dated March 2, 2010, as amended and including the Amendment and Supplement to the Offer to Purchase attached as an exhibit to the Tender Offer Statement on Schedule TO filed by Astellas, AUSH and Purchaser with the Securities and Exchange Commission on May 19, 2010.
( 2)	The Offer expired at 12:00 midnight, New York City time on June 2, 2010. An aggregate of 54,176,003 Shares were validly tendered and not withdrawn (including certain Shares tendered under guaranteed delivery procedures), representing approximately 88% of the Issuer's ourstanding Shares. On June 3, 2010, Purchaser accepted for payment all validly tendered and not withdrawn Shares (excluding certain Shares tendered under guaranteed delivery procedures). Purchaser is the owner of the Shares purchased in the Offer. Prior to the commencement of the Offer on February 18, 2010, AUSH acquired 1,000 Shares through ordinary brokerage transactions at prevailing market prices. Astellas may be deemed to be the indirect beneficial owner of such shares of common stock of the Issuer held by Purchaser and AUSH.

Reporting Owners
Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Astellas Pharma Inc. 3-11, NIHONBASHI-HONCHO 2-CHOME, CHUO-KU TOKYO, M0 103-8411		X
Astellas US Holding, Inc. THREE PARKWAY NORTH DEERFIELD, IL 60015		X
Ruby Acqusition, Inc. THREE PARKWAY NORTH DEERFIELD, IL 60015		X

Signatures
/s/ Linda Friedman, Authorized Officer and Attorney-in-fact		6/3/2010
** Signature of Reporting Person		Date

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
*	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).
Note:	File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
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