sc13d07422ari_05122009.htm

BVF PARTNERS L.P. *

BVF Inc., its general partner

/s/ Mark N. Lampert

Mark N. Lampert

President

CUSIP NO. 04033A100

1	NAME OF REPORTING PERSON Biotechnology Value Fund, L.P.
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP		(a) x (b) o
3	SEC USE ONLY
4	SOURCE OF FUNDS WC
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e)		¨
6	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH	7	SOLE VOTING POWER 0
	8	SHARED VOTING POWER 1,969,382 (1)
	9	SOLE DISPOSITIVE POWER 0
	10	SHARED DISPOSITIVE POWER 1,969,382 (1)
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 1,969,382 (1)
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES		o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 2.26%
14	TYPE OF REPORTING PERSON PN

(1) Includes 178,196 shares of Common Stock purchasable upon the exercise of certain warrants.

CUSIP NO. 04033A100

1	NAME OF REPORTING PERSON Biotechnology Value Fund II, L.P.
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP		(a) x (b) o
3	SEC USE ONLY
4	SOURCE OF FUNDS WC
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e)		¨
6	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH	7	SOLE VOTING POWER 0
	8	SHARED VOTING POWER 1,358,566 (1)
	9	SOLE DISPOSITIVE POWER 0
	10	SHARED DISPOSITIVE POWER 1,358,566 (1)
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 1,358,566 (1)
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES		o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 1.56%
14	TYPE OF REPORTING PERSON PN

(1) Includes 124,957 shares of Common Stock purchasable upon the exercise of certain warrants.

CUSIP NO. 04033A100

1	NAME OF REPORTING PERSON BVF Investments, L.L.C.
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP		(a) x (b) o
3	SEC USE ONLY
4	SOURCE OF FUNDS WC
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e)		¨
6	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH	7	SOLE VOTING POWER 0
	8	SHARED VOTING POWER 4,754,737 (1)
	9	SOLE DISPOSITIVE POWER 0
	10	SHARED DISPOSITIVE POWER 4,754,737 (1)
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 4,754,737 (1)
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES		o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 5.45%
14	TYPE OF REPORTING PERSON OO

(1) Includes 449,887 shares of Common Stock purchasable upon the exercise of certain warrants.

CUSIP NO. 04033A100

1	NAME OF REPORTING PERSON Investment 10, L.L.C.
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP		(a) x (b) o
3	SEC USE ONLY
4	SOURCE OF FUNDS WC
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e)		¨
6	CITIZENSHIP OR PLACE OF ORGANIZATION Illinois
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH	7	SOLE VOTING POWER 0
	8	SHARED VOTING POWER 568,810 (1)
	9	SOLE DISPOSITIVE POWER 0
	10	SHARED DISPOSITIVE POWER 568,810 (1)
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 568,810 (1)
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES		o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 0.65%
14	TYPE OF REPORTING PERSON OO

(1) Includes 45,776 shares of Common Stock purchasable upon the exercise of certain warrants.

CUSIP NO. 04033A100

1	NAME OF REPORTING PERSON BVF Partners L.P.
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP		(a) x (b) o
3	SEC USE ONLY
4	SOURCE OF FUNDS OO
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e)		¨
6	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH	7	SOLE VOTING POWER 0
	8	SHARED VOTING POWER 8,651,495 (1)
	9	SOLE DISPOSITIVE POWER 0
	10	SHARED DISPOSITIVE POWER 8,651,495 (1)
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 8,651,495 (1)
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES		o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 9.87%
14	TYPE OF REPORTING PERSON PN, HC

(1) Includes 798,816 shares of Common Stock purchasable upon the exercise of certain warrants.

CUSIP NO. 04033A100

1	NAME OF REPORTING PERSON BVF Inc.
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP		(a) x (b) o
3	SEC USE ONLY
4	SOURCE OF FUNDS OO
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e)		¨
6	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH	7	SOLE VOTING POWER 0
	8	SHARED VOTING POWER 8,651,495 (1)
	9	SOLE DISPOSITIVE POWER 0
	10	SHARED DISPOSITIVE POWER 8,651,495 (1)
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 8,651,495 (1)
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES		o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 9.87%
14	TYPE OF REPORTING PERSON HC, CO

(1) Includes 798,816 shares of Common Stock purchasable upon the exercise of certain warrants.

CUSIP NO. 04033A100

1	NAME OF REPORTING PERSON Mark N. Lampert
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP		(a) x (b) o
3	SEC USE ONLY
4	SOURCE OF FUNDS OO
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e)		¨
6	CITIZENSHIP OR PLACE OF ORGANIZATION USA
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH	7	SOLE VOTING POWER 0
	8	SHARED VOTING POWER 8,651,495 (1)
	9	SOLE DISPOSITIVE POWER 0
	10	SHARED DISPOSITIVE POWER 8,651,495 (1)
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 8,651,495 (1)
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES		o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 9.87%
14	TYPE OF REPORTING PERSON IN

(1) Includes 798,816 shares of Common Stock purchasable upon the exercise of certain warrants.

CUSIP NO. 04033A100

ITEM 1. Security and Issuer

This Schedule 13D is being filed with respect to the common stock, par value $0.001 per share ("Common Stock"), of ARIAD Pharmaceuticals, Inc., a Massachusetts corporation (“ARIAD” or the “Issuer”). The Reporting Persons' percentage ownership of Common Stock is based on 7,852,679 shares of Common Stock owned by the Reporting Persons and 798,816 shares of Common Stock purchasable by the Reporting Persons upon the exercise of certain warrants (the “Warrants”). The principal executive office of ARIAD is located at 26 Lansdowne Street, Cambridge, Massachusetts 02139.

ITEM 2. Identity and Background.

The persons filing this Statement, the persons enumerated in Instruction C of this Statement and, where applicable, their respective places of organization, principal office, general partners, managers, directors, executive officers, controlling persons and certain information regarding each of them, are as follows:

(a) Biotechnology Value Fund, L.P., a Delaware limited partnership ("BVF"), Biotechnology Value Fund II, L.P., a Delaware limited partnership ("BVF2"), BVF Investments, L.L.C., a Delaware limited liability company ("BVLLC"), Investment 10, L.L.C., an Illinois limited liability company ("ILL10"), BVF Partners L.P., a Delaware limited partnership ("Partners") and BVF Inc., a Delaware corporation ("BVF Inc."). Mark N. Lampert, an individual, ("Lampert"), is the sole shareholder, sole director and an officer of BVF Inc.

Each of the foregoing is referred to as a "Reporting Person" and collectively as the “Reporting Persons.” Each of the Reporting Persons is party to that certain Joint Filing Agreement, as further described in Item 6. Accordingly, the Reporting Persons are hereby filing a joint Schedule 13D.

(b) The business address of BVF, BVF2, BVLLC, ILL10 and Partners is 900 North Michigan Avenue, Suite 1100, Chicago, Illinois 60611. The business address of BVF Inc. and Lampert is One Sansome Street, 30th Floor, San Francisco, California 94104.

(c) Each of BVF, BVF2, BVLLC, ILL10, Partners and BVF Inc. specializes in holding biotechnology stocks for investment purposes. Partners is the general partner of BVF and BVF2, which are investment funds. Partners also is the manager of BVLLC, which is also an investment fund. ILL10 is a managed account, which Partners advises pursuant to an investment management agreement. BVF Inc. is an investment adviser to and general partner of Partners. For Lampert's occupation, please refer to (a) above.

(d) During the last five years, none of the Reporting Persons has been convicted in a criminal proceeding (excluding traffic violations and similar misdemeanors).

(e) During the last five years, none of the Reporting Persons has been a party to a civil proceeding of a judicial or administrative body of competent jurisdiction nor, as a result of such proceeding, was or is subject to a judgment, decree or final order enjoining future violations of, or prohibiting or mandating activities subject to, federal or state securities laws or finding any violation with respect to such laws.

(f) Lampert is a citizen of the United States of America. For the citizenship of each of BVF, BVF2, BVLLC, ILL10, Partners and BVF Inc., please refer to (a) above.

CUSIP NO. 04033A100

ITEM 3. Source and Amount of Funds or Other Consideration

Partners, in its capacity as (i) general partner of BVF, has purchased on behalf of such limited partnership an aggregate number of 1,969,382 shares of Common Stock for an aggregate consideration of $5,594,687.00, (ii) general partner of BVF2, has purchased on behalf of such limited partnership an aggregate number of 1,358,566 shares of Common Stock for an aggregate consideration of $3,844,788.00, (iii) manager of BVLLC, has purchased on behalf of such limited liability company an aggregate number of 4,754,737 shares of Common Stock for an aggregate consideration of $13,387,527.00, and (iv) investment adviser to ILL10, purchased on behalf of such limited liability company an aggregate of 568,810 shares of Common Stock for an aggregate consideration of $1,653,838.00. Each of BVF, BVF2, BVLLC and ILL10 purchased the shares of Common Stock held by it using its own working capital. No borrowed funds were used to purchase the Common Stock other than any borrowed funds used for working capital purposes in the ordinary course of business.

ITEM 4. Purpose of Transaction

The Reporting Persons intend to review their investment in the Issuer on a continuing basis and may engage in discussions with management and the board of directors of the Issuer, other holders of Common Stock and other relevant parties concerning the business, operations, governance, strategy, capitalization, ownership and future plans of the Issuer.

The Reporting Persons purchased the shares of Common Stock based on the Reporting Persons’ belief that the shares of Common Stock, when purchased, were undervalued and represented an attractive investment opportunity. No Reporting Person has any present plan or proposal which would relate to or result in any of the matters set forth in subparagraphs (a) - (j) of Item 4 of Schedule 13D except as set forth herein or such as would occur upon completion of any of the actions discussed above.

ITEM 5. Interest in Securities of the Issuer

The Reporting Persons’ percentage ownership of Common Stock is based on 86,850,616 shares of Common Stock outstanding, as reported in the Issuer’s Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission on May 11, 2009.

(a) As of the close of business on May 12, 2009, BVF beneficially owned 1,969,382 shares of Common Stock, including 178,196 shares of Common Stock purchasable upon the exercise of the Warrants held by it, BVF2 beneficially owned 1,358,566 shares Common Stock, including 124,957 shares of Common Stock purchasable upon exercise of the Warrants held by it, BVLLC beneficially owned 4,754,737 shares of Common Stock, including 449,887 shares of Common Stock purchasable upon exercise of the Warrants held by it, ILL10 beneficially owned 568,810 shares of Common Stock, including 45,776 shares of Common Stock purchasable upon exercise of the Warrants held by it, representing percentage ownership of approximately 2.26%, 1.56%, 5.45%, 0.65%, respectively.

CUSIP NO. 04033A100

Each of Partners, BVF Inc. and Lampert may be deemed to beneficially own 8,651,495 shares of Common Stock, including 798,816 shares of Common Stock purchasable upon exercise of certain Warrants, representing percentage ownership of approximately 9.87%.

(b) Each of BVF, BVF2, BVLLC and ILL10 shares with Partners voting and dispositive power over the Common Stock each such entity beneficially owns. Partners, BVF Inc. and Lampert share voting and dispositive power over the 8,651,495 shares of Common Stock they may be deemed beneficially to own with BVF, BVF2 and BVLLC, and ILL10.

BVF

ILL10

BVF2

BVLLC

Date of

Transaction

Type of

Securities

Price Per Share

Exchange

Type of

Transaction

04/01/09

Common Stock

1.29470

6,843

2,000

4,000

15,000

NASDAQ

PURCHASE

04/03/09

Common Stock

1.22360

6,000

1,000

4,000

14,000

NASDAQ

PURCHASE

(d) No person other than the Reporting Persons is known to have the right to receive, or the power to direct the receipt of dividends from, or proceeds from the sale of, such shares of the Common Stock.

(e) N/A.

ITEM 6. Contracts, Arrangements, Understandings or Relationships with Respect to Securities of the Issuer

Partners is the general partner of each of BVF and BVF2 pursuant to limited partnership agreements which authorize Partners, among other things, to invest the funds of BVF and BVF2 in the shares of Common Stock and other securities and to vote, exercise or convert and dispose of such securities. Pursuant to such limited partnership agreements, Partners is entitled to receive fees based on assets under management and allocations based on realized and unrealized gains on such assets. Pursuant to the operating agreement of BVLLC, Partners is authorized, among other things, to invest the funds of Ziff Asset Management, L.P., the majority member of BVLLC, in the shares of Common Stock and other securities and to vote, exercise or convert and dispose of such securities and is entitled to receive fees based on assets under management and allocations based on realized and unrealized gains on such assets. Pursuant to an investment management agreement with ILL10, Partners and BVF Inc. have authority, among other things, to invest funds of ILL10 in the shares of Common Stock and other securities and to vote, exercise or convert and dispose of such securities. Pursuant to such investment management agreement, Partners and BVF Inc. receive fees based on realized and unrealized gains thereon. BVF Inc. is the general partner of Partners and may be deemed to own beneficially securities over which Partners exercises voting and dispositive power.

On May 13, 2009, the Reporting Persons entered into a Joint Filing Agreement in which the Reporting Persons agreed to the joint filing on behalf of each of them of statements on Schedule 13D, with respect to securities of the Issuer, to the extent required by applicable law. A copy of this agreement is attached hereto as Exhibit A hereto and is incorporated herein by reference.

CUSIP NO. 04033A100

Other than as described herein, there are no contracts, arrangements, understandings or relationships among the Reporting Persons, or between the Reporting Persons and any other person, with respect to the securities of the Issuer.

ITEM 7. Material to be filed as Exhibits

A Joint Filing Agreement on behalf of the Reporting Persons is filed herewith as Exhibit A.

Signature

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

Dated: May 13, 2009

BIOTECHNOLOGY VALUE FUND, L.P.*
By:	BVF Partners L.P., its general partner
	By:	BVF Inc., its general partner
		By:	/s/ Mark N. Lampert
			Mark N. Lampert President

BIOTECHNOLOGY VALUE FUND II, L.P.*
By:	BVF Partners L.P., its general partner
	By:	BVF Inc., its general partner
		By:	/s/ Mark N. Lampert
			Mark N. Lampert President

BVF INVESTMENTS, L.L.C.*
By:	BVF Partners L.P., its manager
	By:	BVF Inc., its general partner
		By:	/s/ Mark N. Lampert
			Mark N. Lampert President

CUSIP NO. 04033A100

INVESTMENT 10, L.L.C.*
By:	BVF Partners L.P., its investment manager
	By:	BVF Inc., its general partner
		By:	/s/ Mark N. Lampert
			Mark N. Lampert President

		BVF INC.*
		By:		/s/ Mark N. Lampert
				Mark N. Lampert President

/s/ Mark N. Lampert

Mark N. Lampert

*The Reporting Person disclaims beneficial ownership of the shares of Common Stock except to the extent of his or its pecuniary interest therein.

CUSIP NO. 04033A100

Exhibit A

JOINT FILING AGREEMENT

In accordance with Rule 13d-1(k)(l)(iii) under the Securities Exchange Act of 1934, as amended, the persons named below agree to the joint filing on behalf of each of them that this Schedule 13D filed on May 13, 2009 (including amendments thereto) with respect to the shares of Common Stock of ARIAD Pharmaceuticals, Inc. This Joint Filing Agreement shall be field as an Exhibit to such Statement.

BIOTECHNOLOGY VALUE FUND, L.P.
By:	BVF Partners L.P., its general partner
	By:	BVF Inc., its general partner
		By:	/s/ Mark N. Lampert
			Mark N. Lampert President

BIOTECHNOLOGY VALUE FUND II, L.P.
By:	BVF Partners L.P., its general partner
	By:	BVF Inc., its general partner
		By:	/s/ Mark N. Lampert
			Mark N. Lampert President

BVF INVESTMENTS, L.L.C.
By:	BVF Partners L.P., its manager
	By:	BVF Inc., its general partner
		By:	/s/ Mark N. Lampert
			Mark N. Lampert President

INVESTMENT 10, L.L.C.
By:	BVF Partners L.P., its investment manager
	By:	BVF Inc., its general partner
		By:	/s/ Mark N. Lampert
			Mark N. Lampert President

CUSIP NO. 04033A100

BVF PARTNERS L.P.
By:	BVF Inc., its general partner
	By:	/s/ Mark N. Lampert
		Mark N. Lampert President

/s/ Mark N. Lampert

Mark N. Lampert