Company Description
Ironwood Pharmaceuticals, Inc. (Nasdaq: IRWD) is a biotechnology company focused on developing and commercializing therapies for people living with gastrointestinal (GI) and rare diseases. The company’s work centers on conditions that can significantly affect quality of life, such as irritable bowel syndrome with constipation (IBS-C), chronic idiopathic constipation (CIC), functional constipation in children, and short bowel syndrome with intestinal failure (SBS-IF). Ironwood trades on the Nasdaq Global Select Market under the symbol IRWD and operates within the pharmaceutical preparation manufacturing industry.
According to the company, Ironwood has been a pioneer in the development of LINZESS® (linaclotide), which it describes as the U.S. branded prescription market leader for adults with IBS-C or CIC. LINZESS is a once-daily capsule indicated for IBS-C and CIC in adults and for functional constipation in pediatric patients 6 to 17 years of age. It is not classified as a laxative; instead, it is the first medicine approved by the U.S. Food and Drug Administration (FDA) in a class called GC-C agonists, reflecting its mechanism of action on the guanylate cyclase-C receptor in the intestine. In the United States, Ironwood and AbbVie co-develop and co-commercialize LINZESS, and linaclotide is also marketed by partners in Europe, Japan, China and other territories under various brand names.
Beyond its established GI franchise, Ironwood is advancing apraglutide, described by the company as a next-generation, long-acting synthetic GLP-2 analog. Apraglutide is being developed for short bowel syndrome (SBS) patients who are dependent on parenteral support, a severe chronic malabsorptive condition. Ironwood reports that apraglutide has generated strong safety and efficacy data in the STARS Phase 3 trial and in the STARS Extend long-term extension study, where multiple apraglutide-dosed patients achieved enteral autonomy, which the company characterizes as the ultimate goal for these patients. Following feedback from the FDA, Ironwood is working on a confirmatory Phase 3 trial design for SBS-IF and views apraglutide as a core part of its rare disease strategy.
Ironwood’s business model combines internal drug development with global collaborations. For LINZESS in the U.S., AbbVie provides U.S. net sales figures and the two companies share equally in U.S. brand collaboration profits. Outside the U.S., AbbVie markets linaclotide as CONSTELLA® in Europe for adults with moderate to severe IBS-C, Astellas markets linaclotide in Japan for adults with IBS-C or CIC, and AstraZeneca is a partner for development and commercialization in China. Ironwood’s revenues are closely tied to its share of net profits from LINZESS sales in the U.S., along with royalties and other collaboration-related income.
The company has highlighted LINZESS prescription demand growth over multiple reporting periods, based on IQVIA data, and has discussed commercial margin and collaboration revenue associated with the brand. At the same time, Ironwood has emphasized disciplined expense management, restructuring efforts, and adjusted EBITDA as key financial metrics. In public communications, Ironwood has described initiatives to streamline operations, reduce operating expenses, and focus resources on its GI and rare disease priorities, particularly LINZESS and apraglutide.
From a regulatory and corporate governance perspective, Ironwood files periodic and current reports with the U.S. Securities and Exchange Commission (SEC), including Forms 10-K, 10-Q and 8-K. SEC filings in 2025 reference matters such as changes in the company’s independent registered public accounting firm, material weaknesses in internal control over financial reporting as of December 31, 2024, Nasdaq notifications regarding bid price compliance, and a Nasdaq notice related to a delayed Form 10-K filing. The company has also disclosed engagement of financial advisors to explore strategic alternatives, which it describes as an effort to maximize stockholder or shareholder value.
Ironwood was founded in 1998 and is headquartered in Boston, Massachusetts, with an additional site in Basel, Switzerland. Across its communications, the company states that it keeps patients at the heart of its research and development and commercialization efforts, with the goal of reducing the burden of disease and addressing significant unmet needs in GI and rare disease populations.
Key therapeutic focus areas
- Irritable bowel syndrome with constipation (IBS-C) in adults and pediatric patients 7 years and older, through LINZESS.
- Chronic idiopathic constipation (CIC) in adults, treated with LINZESS.
- Functional constipation in children and adolescents 6 to 17 years of age, for which LINZESS is approved.
- Short bowel syndrome with intestinal failure (SBS-IF) in adults dependent on parenteral support, targeted by apraglutide.
Collaborations and geographic reach
- Co-development and co-commercialization of LINZESS in the United States with AbbVie.
- Marketing of linaclotide as CONSTELLA in Europe by AbbVie for adults with moderate to severe IBS-C.
- Marketing of linaclotide in Japan by Astellas for adults with IBS-C or CIC.
- Partnership with AstraZeneca for development and commercialization of LINZESS in China, and with AbbVie for linaclotide in other territories worldwide.
Regulatory and listing status
- Ironwood’s Class A common stock trades on the Nasdaq Global Select Market under the symbol IRWD.
- SEC Form 8-K filings in 2025 confirm continued listing on Nasdaq, including a notice of regained compliance with the minimum bid price requirement under Nasdaq Listing Rule 5450(a)(1).
- An 8-K dated March 27, 2025 notes a Nasdaq non-compliance notification related to a delayed Form 10-K filing, which the company stated it planned to address by filing as soon as practicable.
Risk and safety considerations
Because Ironwood’s marketed and investigational products address serious GI and rare diseases, safety and regulatory labeling are central to its operations. Public materials for LINZESS include a boxed warning regarding the risk of serious dehydration in pediatric patients less than 2 years of age, contraindications in patients under 2 years old and in patients with known or suspected mechanical gastrointestinal obstruction, and information on common adverse reactions such as diarrhea, abdominal pain, flatulence and abdominal distension in adults, and diarrhea in pediatric patients.