UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

Current Report Pursuant to

Section 13 or 15(d) of the

Securities Exchange Act of 1934

Date of Report (Date of Earliest Event Reported):

November 25, 2025

IRONWOOD PHARMACEUTICALS, INC.

(Exact name of registrant as specified in its charter)

Delaware	001-34620	04-3404176
(State or other jurisdiction		(I.R.S. Employer
of incorporation)	(Commission File Number)	Identification Number)

100 Summer Street, Suite 2300
Boston, Massachusetts				02110
(Address of principal
executive offices)				(Zip code)

(617) 621-7722

(Registrant’s telephone number,

including area code)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

¨	Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

¨	Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

¨	Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

¨	Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class	Trading Symbol(s)	Name of each exchange on which registered
Class A common stock, $0.001 par value	IRWD	Nasdaq Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ¨

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ¨

Item 8.01 Other Events.

On November 25, 2025, the U.S. Department of Health and Human Services released the “Maximum Fair Price” (“MFP”) for LINZESS® (linaclotide), which was selected in the most recent round of government price setting as part of the Inflation Reduction Act of 2022. The MFP for a 30-day equivalent supply of LINZESS, which will become the new Medicare net price as of January 1, 2027, is set to $136. The revised MFP for LINZESS is in line with the expectations of Ironwood Pharmaceuticals, Inc.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

	Ironwood Pharmaceuticals, Inc.

Dated: November 26, 2025	By:	/s/ Gregory Martini
		Name: Gregory Martini
		Title: Senior Vice President, Chief Financial Officer

IRONWOOD PHARMACEUTICALS INC 8-K