IRONWOOD PHARMACEUTICALS INC

Current report

We have received notices of Paragraph IV certifications related to LINZESS in conjunction with ANDAs filed by generic drug manufacturers, and we may receive additional notices from others in the future. We have, and may continue to, become involved in legal proceedings to protect or enforce intellectual property rights relating to our products and our product candidates, which could be expensive and time consuming, and unfavorable outcomes in such proceedings could have a material adverse effect on our business.

Current report

Competitors may infringe the patents relating to our products and our product candidates or may assert that such patents are invalid. To counter ongoing or potential infringement or unauthorized use, we may be required to file infringement claims, which can be expensive and time-consuming. Litigation with generic manufacturers has become increasingly common in the biotechnology and pharmaceutical industries. In addition, in an infringement or invalidity proceeding, a court or patent administrative body may determine that a patent of ours is not valid or is unenforceable, or may refuse to stop the other party from using the technology at issue on the grounds that our patents do not cover the technology in question.

Current report

Generic drug manufacturers were first able to file Abbreviated New Drug Applications, or ANDAs, for generic versions of LINZESS in August 2016. When filing an ANDA for one of our products, a generic drug manufacturer may choose to challenge one or more of the patents that cover such product and seek to commercialize generic versions of one or more LINZESS doses. As such, we have brought, and may bring in the future, legal proceedings against generic drug manufacturers.

Current report

We and AbbVie have received Paragraph IV certification notice letters regarding ANDAs submitted to the U.S. FDA by generic drug manufacturers requesting approval to engage in commercial manufacture, use, sale and offer for sale of linaclotide capsules (72 mcg, 145 mcg and 290 mcg), or Potential Generic Products, proposed generic versions of our U.S. FDA-approved drug LINZESS. Frequently, innovators receive multiple ANDA filings.

Current report

After evaluation, we have in the past filed, and may, in the future, file patent infringement lawsuits or take other action against companies making ANDA filings. If a patent infringement suit has been filed within 45 days of receipt of a notice letter, the U.S. FDA is not permitted to approve any ANDA that is the subject of such lawsuit for 30 months from the date of the New Drug Application holder’s and patent owner’s receipt of the ANDA filer’s notice letter, or until a court decides that the relevant patents are invalid, unenforceable and/or not infringed. We have previously entered into settlement agreement with five of these filers.

Current report

On June 12, 2026, we received a notice letter relating to an ANDA that was submitted to the U.S. FDA by Alkem Laboratories Ltd., or Alkem. Alkem’s notice letter contends that the U.S. patents for LINZESS listed in the U.S. FDA’s list of Approved Drug Products with Therapeutic Equivalence Evaluations, commonly referred to as the Orange Book, are invalid, unenforceable and/or would not be infringed by Alkem’s manufacture, use, sale or offer for sale of Alkem’s Potential Generic Products. In response to Alkem’s notice letter, we and AbbVie filed a lawsuit against Alkem in the U.S. District Court for the District of New Jersey in July 2026. We asserted that the challenged patents are valid and infringed by Alkem. In accordance with the Hatch-Waxman Act, the timely filing of the lawsuit against Alkem with respect to the challenged patents triggered an automatic stay of the U.S. FDA’s approval of the ANDAs until up to December 12, 2028 (unless there is a court decision adverse to us and AbbVie sooner).

Current report

We may receive additional notice letters regarding ANDAs submitted to the U.S. FDA (and we may receive amendments to notice letters), but we may not become aware of these filings for several months after any such submission due to procedures specified under applicable U.S. FDA regulations.

Current report

Additionally, the validity of the patents relating to our products and our product candidates may be challenged by third parties pursuant to administrative procedures introduced by the America Invents Act, specificallyinter partesreview, or IPR, and/or post grant review, or PGR, before the U.S. Patent and Trademark Office, or the USPTO. Generic drug manufacturers may challenge our patents through IPRs or PGRs instead of or in addition to ANDA legal proceedings.

Current report

Patent litigation (including any lawsuits that we file against generic drug manufacturers in connection with the receipt of a notice letter), IPRs and PGRs involve complex legal and factual questions and we may need to devote significant resources to such legal proceedings. We can provide no assurance concerning the duration or the outcome of any such patent-related lawsuits or administrative proceedings, including any settlements or other resolutions thereof which could, in addition to other risks, result in a shortening of exclusivity periods. An adverse result in any litigation or defense proceedings could put one or more of the patents relating to our products and our product candidates at risk of being invalidated or interpreted narrowly, or could otherwise result in a loss of patent protection for the product or product candidate at issue, and could put our patent applications at risk of not issuing, which would materially harm our business. Upon any loss of patent protection for one of our products, or upon an “at-risk” launch (despite pending patent infringement litigation, before any court decision or while an appeal of a lower court decision is pending) by a manufacturer of a generic version of one of our patented products, our revenues for that product could be significantly reduced in a short period of time, which would materially and adversely affect our business.

Current report

Interference or derivation proceedings brought by the USPTO may be necessary to determine the priority of inventions with respect to the patents relating to our products and our product candidates and patent applications or those of our partners. An unfavorable outcome could require us to cease using the technology or to attempt to license rights to it from the prevailing party. Our business could be harmed if a prevailing party does not offer us a license on terms that are acceptable to us. Litigation or interference proceedings may fail and, even if successful, may result in substantial costs and distraction of our management and other employees. In addition, we may not be able to prevent, alone or with our partners, misappropriation of our proprietary rights, particularly in countries where the laws may not protect those rights as fully as in the U.S.

Current report

Furthermore, because of the substantial amount of discovery required in connection with intellectual property litigation, as well as the potential for public announcements of the results of hearings, motions or other interim proceeding or developments, there is a risk that some of our confidential information could be compromised by disclosure during this type of litigation.