IRONWOOD PHARMACEUTICALS INC

We are a biotechnology company developing and commercializing life-changing therapies for people living with gastrointestinal, or GI, and rare diseases. We are focused on the development and commercialization of innovative product opportunities in areas of significant unmet need, leveraging our demonstrated expertise and capabilities in GI and rare diseases.

LINZESS (linaclotide), our commercial product, is the first product approved by the United States Food and Drug Administration, or U.S. FDA, in a class of GI medicines called guanylate cyclase type C agonists, or GC-C agonists, and is indicated for the treatment, in the U.S., of irritable bowel syndrome with constipation, or IBS-C, in adults and pediatric patients 7 years of age and older, chronic idiopathic constipation, or CIC, in adults, and functional constipation, or FC, in pediatric patients ages 6-17 years-old. LINZESS is also available for the treatment of adults with IBS-C or CIC in Mexico, adults with IBS-C or chronic constipation in Japan, and adults with IBS-C in China. Linaclotide is available under the trademarked name CONSTELLA for the treatment of adults with IBS-C or CIC and pediatric patients ages 6-17 years old with FC in Canada, and to adults with IBS-C in certain European countries.

We have strategic partnerships with leading pharmaceutical companies to support the development and commercialization of linaclotide throughout the world, including with our partner, AbbVie Inc. (together with its affiliates), or AbbVie, in the U.S. and all countries worldwide other than China (including Hong Kong and Macau) and Japan, AstraZeneca AB (together with its affiliates), or AstraZeneca, in China (including Hong Kong and Macau) and Astellas Pharma Inc., or Astellas, in Japan.

Through our acquisition of VectivBio Holding AG, or VectivBio, in June 2023, or the VectivBio Acquisition, we are advancing apraglutide, a next-generation, synthetic long-acting peptide analog of glucagon-like peptide-2, or GLP-2, for short bowel syndrome, or SBS, patients who are dependent on parenteral support, or PS. In February 2024, we announced positive topline results from our pivotal Phase III clinical trial, STARS, which evaluated the efficacy and safety of once-weekly subcutaneous apraglutide in reducing PS dependency in adult patients with short bowel syndrome with intestinal failure, or SBS-IF. We are also conducting an open-label extension study, STARS Extend, to further assess the safety of apraglutide in adult patients with SBS-IF. In April 2025, we announced that, based on discussions with the U.S. FDA, a confirmatory Phase III clinical trial is needed to seek approval of a new drug application or NDA, for apraglutide for patients with SBS-IF who are dependent on PS. In the fourth quarter of 2025, we met with the U.S. FDA and aligned on key design elements of a confirmatory Phase III clinical trial, STARS-2, of apraglutide. Site initiations are expected to begin in the second quarter of 2026.