Sec Form 4 Filing - Hecht Peter M @ IRONWOOD PHARMACEUTICALS INC - 2019-04-01

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP 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

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1. Name and Address of Reporting Person Hecht Peter M 2. Issuer Name and Ticker or Trading Symbol IRONWOOD PHARMACEUTICALS INC [ IRWD] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director _____ 10% Owner X __ Officer (give title below) _____ Other (specify below) Chief Executive Officer (Last) (First) (Middle) C/O IRONWOOD PHARMACEUTICALS, INC., 301 BINNEY STREET 3. Date of Earliest Transaction (MM/DD/YY) 04/01/2019 (Street) CAMBRIDGE, MA02142 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares Employee Stock Option (Right to Buy) $ 4.88 ( 1 ) 04/01/2019 D 20,000 ( 1 ) ( 2 ) 07/28/2019 Class A Common Stock 20,000 ( 1 ) 20,000 D Employee Stock Option (Right to Buy) $ 9.89 ( 3 ) 04/01/2019 D 44,020 ( 3 ) ( 4 ) 02/01/2021 Class A Common Stock 44,020 ( 3 ) 130,980 D Employee Stock Option (Right to Buy) $ 13.11 ( 5 ) 04/01/2019 D 7,533 ( 5 ) ( 4 ) 02/01/2022 Class A Common Stock 7,533 ( 5 ) 292,467 D Employee Stock Option (Right to Buy) $ 11.65 ( 6 ) 04/01/2019 D 7,645 ( 6 ) ( 4 ) 02/01/2023 Class A Common Stock 7,645 ( 6 ) 367,355 D Employee Stock Option (Right to Buy) $ 12.56 ( 7 ) 04/01/2019 D 6,771 ( 7 ) ( 4 ) 03/03/2024 Class A Common Stock 6,771 ( 7 ) 318,229 D Employee Stock Option (Right to Buy) $ 9.12 ( 1 ) 04/01/2019 D 166,875 ( 1 ) ( 8 ) 03/01/2026 Class A Common Stock 166,875 ( 1 ) 723,125 D Employee Stock Option (Right to Buy) $ 14.93 ( 1 ) 04/01/2019 D 332,500 ( 1 ) ( 9 ) 02/27/2027 Class A Common Stock 332,500 ( 1 ) 427,500 D Employee Stock Option (Right to Buy) $ 12.95 ( 1 ) 04/01/2019 D 398,750 ( 1 ) ( 10 ) 02/21/2028 Class A Common Stock 398,750 ( 1 ) 181,250 D Employee Stock Option (Right to Buy) $ 11.49 ( 1 ) 04/01/2019 D 937,500 ( 1 ) ( 11 ) 01/29/2029 Class A Common Stock 937,500 ( 1 ) 62,500 D Employee Stock Option (Right to Buy) $ 10.02 ( 12 ) ( 4 ) 02/02/2020 Class A Common Stock 125,000 125,000 D Employee Stock Option (Right to Buy) $ 13.91 ( 12 ) ( 4 ) 03/16/2025 Class A Common Stock 565,000 565,000 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Hecht Peter M C/O IRONWOOD PHARMACEUTICALS, INC. 301 BINNEY STREET CAMBRIDGE, MA02142 X Chief Executive Officer Signatures /s/ Conor Kilroy, Attorney-in-Fact 04/03/2019 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Represents options to purchase Ironwood Class A Common Stock awarded to the reporting person prior to the separation (the "Separation") of Cyclerion Therapeutics, Inc. ("Cyclerion") from Ironwood Pharmaceuticals, Inc. ("Ironwood"). In connection with the Separation, the unvested portion of the Ironwood option award was replaced with an option to purchase shares of Cyclerion Common Stock. The exercise price of the vested portion of the Ironwood option award has been adjusted, and the reporting person received additional options to purchase shares of Cyclerion Common Stock, to preserve the pre-Separation intrinsic value of the vested portion of the Ironwood option award. ( 2 )The remaining 20,000 shares are presently exercisable in full. ( 3 )Represents options to purchase Ironwood Class A Common Stock awarded to the reporting person prior to the Separation. In connection with the Separation, 44,020 shares of Class A Common Stock underlying this award were replaced with an option to purchase shares of Cyclerion Common Stock. With respect to the remaining 130,980 shares of Class A Common Stock underlying this award, the exercise price was adjusted and the reporting person received options to purchase shares of Cyclerion Common Stock to preserve the pre-Separation intrinsic value of such portion of the Ironwood option award. ( 4 )This option, granted as an annual performance award, is presently exercisable in full. ( 5 )Represents options to purchase Ironwood Class A Common Stock awarded to the reporting person prior to the Separation. In connection with the Separation, 7,533 shares of Class A Common Stock underlying this award were replaced with an option to purchase shares of Cyclerion Common Stock. With respect to the remaining 292,467 shares of Class A Common Stock underlying this award, the exercise price was adjusted and the reporting person received options to purchase shares of Cyclerion Common Stock to preserve the pre-Separation intrinsic value of such portion of the Ironwood option award. ( 6 )Represents options to purchase Ironwood Class A Common Stock awarded to the reporting person prior to the Separation. In connection with the Separation, 7,645 shares of Class A Common Stock underlying this award were replaced with an option to purchase shares of Cyclerion Common Stock. With respect to the remaining 367,355 shares of Class A Common Stock underlying this award, the exercise price was adjusted and the reporting person received options to purchase shares of Cyclerion Common Stock to preserve the pre-Separation intrinsic value of such portion of the Ironwood option award. ( 7 )Represents options to purchase Ironwood Class A Common Stock awarded to the reporting person prior to the Separation. In connection with the Separation, 6,771 shares of Class A Common Stock underlying this award were replaced with an option to purchase shares of Cyclerion Common Stock. With respect to the remaining 318,229 shares of Class A Common Stock underlying this award, the exercise price was adjusted and the reporting person received options to purchase shares of Cyclerion Common Stock to preserve the pre-Separation intrinsic value of such portion of the Ironwood option award. ( 8 )The remaining 723,125 shares are presently exercisable in full. ( 9 )The remaining 427,500 shares are presently exercisable in full. ( 10 )The remaining 181,250 shares are presently exercisable in full. ( 11 )The remaining 62,500 shares are presently exercisable in full. ( 12 )Represents options to purchase Ironwood Class A Common Stock awarded to the reporting person prior to the Separation. In connection with the Separation, the exercise price of the option was adjusted, and the reporting person received options to purchase shares of Cyclerion Common Stock, to preserve the pre-Separation intrinsic value of the existing Ironwood option award.

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 4(b)(v).

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