UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 9)*

ARIAD Pharmaceuticals, Inc.

(Name of Issuer)

Common Stock, $0.001 par value

(Title of Class of Securities)

04033A100

(CUSIP Number)

Mark DiPaolo

General Counsel

Sarissa Capital Management LP

660 Steamboat Road, 3^rd Floor

Greenwich, CT 06830

203-302-2330

With a copy to:

Russell Leaf
Jared Fertman

Willkie Farr & Gallagher LLP

787 Seventh Avenue

New York, New York 10019

212-728-8000

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

February 16, 2017

(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 which is the subject of this Schedule 13D, and is filing this schedule because of Rule 13d-1(e), 13d-1(f) or 13d-1(g), check the following box. ☐

Note: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See Rule 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 disclosures provided in a prior cover page.

The information required on 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 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).

CUSIP No. 04033A100

Page 2 of 7 Pages

SCHEDULE 13D

1	NAME OF REPORTING PERSON OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON Sarissa Capital Management LP
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP			(a) ☐ (b) ☐
3	SEC USE ONLY
4	SOURCE OF FUNDS OO
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 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 0
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 0
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 0
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES:			☐
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 0.0%
14	TYPE OF REPORTING PERSON PN

CUSIP No. 04033A100

Page 3 of 7 Pages

SCHEDULE 13D

1	NAME OF REPORTING PERSON OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON Alexander J. Denner
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP			(a) ☐ (b) ☐
3	SEC USE ONLY
4	SOURCE OF FUNDS OO
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) OR 2(e)			☐
6	CITIZENSHIP OR PLACE OF ORGANIZATION United States
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER 0
		8	SHARED VOTING POWER 0
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 0
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 0
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES:			☐
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 0.0%
14	TYPE OF REPORTING PERSON IN

CUSIP No. 04033A100

Page 4 of 7 Pages

SCHEDULE 13D

1	NAME OF REPORTING PERSON OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON Sarissa Capital Offshore Master Fund LP
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP			(a) ☐ (b) ☐
3	SEC USE ONLY
4	SOURCE OF FUNDS OO
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) OR 2(e)			☐
6	CITIZENSHIP OR PLACE OF ORGANIZATION Cayman Islands
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER 0
		8	SHARED VOTING POWER 0
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 0
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 0
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES:			☐
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 0.0%
14	TYPE OF REPORTING PERSON PN

CUSIP No. 04033A100

Page 5 of 7 Pages

SCHEDULE 13D

1	NAME OF REPORTING PERSON OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON Sarissa Capital Domestic Fund LP
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP			(a) ☐ (b) ☐
3	SEC USE ONLY
4	SOURCE OF FUNDS OO
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 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 0
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 0
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 0
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES:			☐
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 0.0%
14	TYPE OF REPORTING PERSON PN

CUSIP No. 04033A100

Page 6 of 7 Pages

SCHEDULE 13D

Item 1. Security and Issuer.

This statement constitutes Amendment No. 9 (this “Amendment No. 9”) to the Schedule 13D relating to the Common Stock, par value $0.001 (the “Shares”), issued by ARIAD Pharmaceuticals, Inc. (the “Issuer”), and hereby amends the Schedule 13D filed with the Securities and Exchange Commission on October 29, 2013 and amended by Amendment Nos. 1 through 8 thereto (as amended, the "Initial Schedule 13D"), on behalf of the Reporting Persons (as defined in the Initial Schedule 13D), to furnish the additional information set forth herein. All capitalized terms contained herein but not otherwise defined shall have the meanings ascribed to such terms in the Initial Schedule 13D.

Item 4. Purpose of Transaction.

Item 4 of the Initial Schedule 13D is hereby amended and supplemented by adding the following at the end thereof:

Pursuant to the terms of the Merger Agreement, on February 16, 2017, Takeda Pharmaceutical Company Limited acquired all of the Shares of the Issuer, including all of the Shares held by the Reporting Persons, for $24.00 per Share in cash. Accordingly, as of such date, the Reporting Persons ceased to beneficially own any Shares.

Item 5. Interest in Securities of the Issuer.

Items 5(a), (b) and (c) of the Initial Schedule 13D are hereby amended and restated in their entirety as set forth below, and the Initial Schedule 13D is hereby further amended by adding Item 5(e) thereof, which shall read as set forth below:

(a) As a result of the transactions described in Item 4 of this Amendment No. 9, upon the expiration of the Offer and the acceptance of the Shares for payment, which occurred on February 16, 2017, none of the Reporting Persons beneficially own any Shares.

(b) As a result of the transactions described in Item 4 of this Amendment No. 9, upon the expiration of the Offer and the acceptance of the Shares for payment, which occurred on February 16, 2017, none of the Reporting Persons beneficially own any Shares.

(c) Except for the transactions described in Item 4 of this Amendment No. 9, no transaction in the Shares was effected during the past sixty (60) days by any of the Reporting Persons.

(e) As a result of the transactions described in Item 4 of this Amendment No. 9, upon the expiration of the Offer and the acceptance of the Shares for payment, which occurred on February 16, 2017, the Reporting Persons ceased to be the beneficial owners of more than 5% of the Shares.

CUSIP No. 04033A100

Page 7 of 7 Pages

SCHEDULE 13D

SIGNATURE

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

Dated: February 21, 2017

SARISSA CAPITAL MANAGEMENT LP

By:	/s/ Mark DiPaolo
	Name: Mark DiPaolo
	Title: General Counsel

SARISSA CAPITAL DOMESTIC FUND LP

By: Sarissa Capital Fund GP LP, its general partner

By:	/s/ Mark DiPaolo
	Name: Mark DiPaolo
	Title: Authorized Person

SARISSA CAPITAL OFFSHORE MASTER FUND LP

By: Sarissa Capital Offshore Fund GP LLC, its general partner

By:	/s/ Mark DiPaolo
	Name: Mark DiPaolo
	Title: Authorized Person

/s/Alexander J. Denner

Alexander J. Denner

ARIAD PHARMACEUTICALS INC SC 13D/A