Ironwood Pharmaceuticals to Present New Data on Once-Weekly Apraglutide in Short Bowel Syndrome with Intestinal Failure (SBS-IF) at Digestive Disease Week® 2024

Ironwood Pharmaceuticals, Inc. (Nasdaq: IRWD), a GI-focused healthcare company, announced today that the company will present new data from studies evaluating apraglutide in adults with short bowel syndrome with intestinal failure (SBS-IF), a condition in which patients are dependent on parenteral support (PS), during the 2024 Digestive Disease Week® (DDW) meeting. DDW is held from May 18-21, 2024, in Washington, D.C.

SBS-IF, a rare chronic debilitating malabsorptive condition in which patients are dependent on PS, affects an estimated 18,000 adult patients in the U.S., Europe, and Japan. Apraglutide data from the STARS Phase III trial, which evaluated the safety and efficacy of once-weekly apraglutide in reducing PS dependency in adult patients with SBS-IF, will be presented at DDW 2024 as a late-breaker oral presentation. Ironwood announced topline data from the STARS Phase III trial in February 2024.

The late-breaker presentation includes new apraglutide data from the STARS Phase III trial. Based on these results, the company is working to submit a new drug application (NDA) to the U.S. Food and Drug Administration (FDA) and other regulatory filings for apraglutide for use in adult patients with SBS who are dependent on PS.

"Coming off our recently announced positive topline results from STARS, we're excited to share additional study findings that underscore the importance of apraglutide as a potential once-weekly GLP-2 analog for adult patients with SBS who are dependent on parenteral support," said Michael Shetzline, M.D., Ph.D., chief medical officer, senior vice president and head of research and drug development at Ironwood Pharmaceuticals. "We also look forward to showcasing additional real-world insights related to our IBS-C and FC linaclotide portfolio."

In addition to the oral presentation, a series of four posters will highlight findings across the apraglutide development program. Also, three posters will spotlight data on linaclotide in adults with irritable bowel syndrome with constipation (IBS-C), disparities in IBS diagnosis, and real-world prescribing patterns for pediatric patients with functional constipation (FC) and IBS-C. A list of the data presentations is below.

Apraglutide in SBS-IF

• Efficacy and Safety of Apraglutide Once-Weekly in Patients with Short Bowel Syndrome and Intestinal Failure (SBS-IF): Results from the STARS Study - A Global Phase 3 Double-Blind, Randomized, Placebo-Controlled Trial
  • Oral presentation: May 21, 10:30 ? 10:45 am ET.
• Changes in Bowel Morphology and Motility Assessed by MRI in Patients with Short Bowel Syndrome Intestinal Failure (SBS-IF) and Colon-In-Continuity Treated with Apraglutide
  • Poster presentation number Su1946: May 19, 12:30 ? 1:30 pm ET.
• Parenteral Support Weaning, Clinical Benefit and Improved Patient Reported Outcomes in Short Bowel Syndrome Intestinal Failure (SBS-IF) Patients with Colon-In-Continuity Treated with the Long-Acting Glucagon-Like Peptide-2 (GLP-2) Analog Apraglutide
  • Poster presentation number Su1947: May 19, 12:30 ? 1:30 pm ET.
• Apraglutide Treatment in Short Bowel Syndrome with Intestinal Failure (SBS-IF) and Colon-In-Continuity is Associated with Increased Oral Intake and Improved Energy and Carbohydrate Absorption at 48 Weeks
  • Poster presentation number Su1948: May 19, 12:30 ? 1:30 pm ET.
• The Effect of Apraglutide on Gastric Emptying in Healthy Individuals: A Phase 1 Randomized, Placebo-Controlled, Double-Blind, Single-Center Trial
  • Poster presentation number Su1949: May 19, 12:30 ? 1:30 pm ET.

Irritable Bowel Syndrome with Constipation and Functional Constipation

• Real World Prescribing Patterns for Pediatric Patients with Functional Constipation and Irritable Bowel Syndrome with Constipation
  • Poster presentation number Su2047: May 19, 12:30 ? 1:30 pm ET.
• Assessing US Healthcare Disparities in IBS Diagnosis: A National Survey Analysis
  • Poster presentation number Tu1027: May 21, 12:30 ? 1:30 pm ET.
• Efficacy, Safety, and Time to Response of Linaclotide in Patients ?65 with Irritable Bowel Syndrome with Constipation
  • Poster presentation number Tu1653: May 21, 12:30 ? 1:30 pm ET.

About Apraglutide

Apraglutide is an investigational, synthetic GLP-2 analog being developed for a range of rare gastrointestinal diseases where GLP-2 can play a central role in addressing disease pathophysiology, including short bowel syndrome with intestinal failure (SBS-IF) and Acute Graft-Versus-Host Disease (aGVHD).

About LINZESS® (linaclotide)

LINZESS® is the #1 prescribed brand in the U.S. for the treatment of adult patients with irritable bowel syndrome with constipation ("IBS-C") or chronic idiopathic constipation ("CIC"), based on IQVIA data.

LINZESS is a once-daily capsule that helps relieve the abdominal pain, constipation, and overall abdominal symptoms of bloating, discomfort and pain associated with IBS-C, as well as the constipation, infrequent stools, hard stools, straining, and incomplete evacuation associated with CIC. LINZESS relieves constipation in children and adolescents aged 6 to 17 years with functional constipation. The recommended dose is 290 mcg for IBS-C patients and 145 mcg for CIC patients, with a 72 mcg dose approved for use in CIC depending on individual patient presentation or tolerability. In children with functional constipation aged 6 to 17 years, the recommended dose is 72 mcg.

LINZESS is not a laxative; it is the first medicine approved by the FDA in a class called GC-C agonists. LINZESS contains a peptide called linaclotide that activates the GC-C receptor in the intestine. Activation of GC-C is thought to result in increased intestinal fluid secretion and accelerated transit and a decrease in the activity of pain-sensing nerves in the intestine. The clinical relevance of the effect on pain fibers, which is based on nonclinical studies, has not been established.

In the United States, Ironwood and AbbVie co-develop and co-commercialize LINZESS for the treatment of adults with IBS-C or CIC. In Europe, AbbVie markets linaclotide under the brand name CONSTELLA® for the treatment of adults with moderate to severe IBS-C. In Japan, Ironwood's partner, Astellas, markets linaclotide under the brand name LINZESS for the treatment of adults with IBS-C or CIC. Ironwood also has partnered with AstraZeneca for development and commercialization of LINZESS in China, and with AbbVie for development and commercialization of linaclotide in all other territories worldwide.

LINZESS Important Safety Information

INDICATIONS AND USAGE

LINZESS® (linaclotide) is indicated for the treatment of both irritable bowel syndrome with constipation (IBS-C) and chronic idiopathic constipation (CIC) in adults and functional constipation (FC) in children and adolescents 6 to 17 years of age. It is not known if LINZESS is safe and effective in children with FC less than 6 years of age or in children with IBS-C less than 18 years of age.

IMPORTANT SAFETY INFORMATION

WARNING: RISK OF SERIOUS DEHYDRATION IN PEDIATRIC PATIENTS LESS THAN 2 YEARS OF AGE

LINZESS is contraindicated in patients less than 2 years of age. In nonclinical studies in neonatal mice, administration of a single, clinically relevant adult oral dose of linaclotide caused deaths due to dehydration.

Contraindications

• LINZESS is contraindicated in patients less than 2 years of age due to the risk of serious dehydration.
• LINZESS is contraindicated in patients with known or suspected mechanical gastrointestinal obstruction.

Warnings and Precautions

• LINZESS is contraindicated in patients less than 2 years of age. In neonatal mice, linaclotide increased fluid secretion as a consequence of age-dependent elevated guanylate cyclase (GC-C) agonism, which was associated with increased mortality within the first 24 hours due to dehydration. There was no age dependent trend in GC-C intestinal expression in a clinical study of children 2 to less than 18 years of age; however, there are insufficient data available on GC-C intestinal expression in children less than 2 years of age to assess the risk of developing diarrhea and its potentially serious consequences in these patients

Diarrhea

• In adults, diarrhea was the most common adverse reaction in LINZESS-treated patients in the pooled IBS-C and CIC double-blind placebo-controlled trials. The incidence of diarrhea was similar in the IBS-C and CIC populations. Severe diarrhea was reported in 2% of 145 mcg and 290 mcg LINZESS-treated patients and in <1% of 72 mcg LINZESS-treated CIC patients.
• In children and adolescents 6 to 17 years of age, diarrhea was the most common adverse reaction in 72 mcg LINZESS-treated patients in the FC double-blind placebo-controlled trial. Severe diarrhea was reported in <1% of 72 mcg LINZESS treated patients. If severe diarrhea occurs, dosing should be suspended and the patient rehydrated.

Common Adverse Reactions (incidence ?2% and greater than placebo)

• In IBS-C or CIC adult patients: diarrhea, abdominal pain, flatulence, and abdominal distension.
• In FC pediatric patients: diarrhea.

Please see full Prescribing Information including Boxed Warning:
https://www.rxabbvie.com/pdf/linzess_pi.pdf

LINZESS® and CONSTELLA® are registered trademarks of Ironwood Pharmaceuticals, Inc. Any other trademarks referred to in this press release are the property of their respective owners. All rights reserved.

About Ironwood Pharmaceuticals

Ironwood Pharmaceuticals (Nasdaq: IRWD), an S&P SmallCap 600® company, is a leading global gastrointestinal (GI) healthcare company on a mission to advance the treatment of GI diseases and redefine the standard of care for GI patients. We are pioneers in the development of LINZESS® (linaclotide), which is the U.S. branded prescription market leader for adults with irritable bowel syndrome with constipation (IBS-C) or chronic idiopathic constipation (CIC) and is also indicated for the treatment of functional constipation in pediatric patients ages 6-17 years old. Ironwood is also advancing apraglutide, a next-generation, long-acting synthetic GLP-2 analog being developed for rare gastrointestinal diseases, including short bowel syndrome with intestinal failure (SBS-IF) as well as several earlier stage assets. Building upon our history of GI innovation, we keep patients at the heart of our R&D and commercialization efforts to reduce the burden of GI diseases and address significant unmet needs. Founded in 1998, Ironwood Pharmaceuticals is headquartered in Boston, Massachusetts, with a site in Basel, Switzerland.

We routinely post information that may be important to investors on our website at www.ironwoodpharma.com. In addition, follow us on X and on LinkedIn.

Forward-Looking Statements

This press release contains forward-looking statements. Investors are cautioned not to place undue reliance on these forward-looking statements, including statements about the assessment of the data from the Phase III STARS clinical trial of apraglutide; the safety, tolerability and efficacy of apraglutide; the estimated adult population who suffer from SBS-IF in the U.S., Europe and Japan; Ironwood's plan to submit an NDA for apraglutide with the FDA for use in adult patients with SBS who are dependent on PS; and the potential of apraglutide to be, if approved, a once-weekly GLP-2 analog for adult patients with SBS who are dependent on PS. These forward-looking statements speak only as of the date of this press release, and Ironwood undertakes no obligation to update these forward-looking statements. Each forward-looking statement is subject to risks and uncertainties that could cause actual results to differ materially from those expressed or implied in such statement. Applicable risks and uncertainties include those related to the effectiveness of development and commercialization efforts by us and our partners; preclinical and clinical development, manufacturing and formulation development of apraglutide; the risk that clinical programs and studies may not progress or develop as anticipated, including that studies are delayed or discontinued for any reason, such as safety, tolerability, enrollment, manufacturing, economic or other reasons; the risk that findings from completed nonclinical and clinical studies may not be replicated in later studies; the risk that the FDA may not approve our NDA submission; the risk of competition or that new products may emerge that provide different or better alternatives for treatment of the conditions that our products are approved to treat; the risk that healthcare reform and other governmental and private payor initiatives may have an adverse effect upon or prevent our products' or product candidates' commercial success; the efficacy, safety and tolerability of our product candidates; the risk that the commercial and therapeutic opportunities for our product candidates are not as we expect; the risk that we are unable to successfully partner with other companies to develop and commercialize products or product candidates; decisions by regulatory and judicial authorities; the risk we may never get additional patent protection for our product candidates, that patents for our products may not provide adequate protection from competition, or that we are not able to successfully protect such patents; the risk that the development of apraglutide is not successful or that any of our product candidates does not receive regulatory approval or is not successfully commercialized; outcomes in legal proceedings to protect or enforce the patents relating to our products and product candidates, including abbreviated new drug application litigation; challenges from and rights of competitors or potential competitors; and the risks listed under the heading "Risk Factors" and elsewhere in our Annual Report on Form 10-K for the year ended December 31, 2023, and in our subsequent Securities and Exchange Commission filings.