BOSTON — Ironwood Pharmaceuticals, Inc. reported stronger first-quarter results for 2026, driven by sharply higher U.S. net sales of LINZESS and continued progress in its rare gastrointestinal disease pipeline.
The Boston biotechnology company said total revenue rose to $106.5 million in the first quarter, up from $41.1 million in the same period last year. Ironwood posted GAAP net income of $40.8 million, or 25 cents per basic share and 24 cents per diluted share, compared with a GAAP net loss of $37.4 million, or 23 cents per share, in the first quarter of 2025.
Adjusted EBITDA was $76.7 million, compared with a loss of $4.7 million a year earlier. Ironwood also maintained its full-year 2026 financial guidance.
“Our first quarter of 2026 delivered strong financial performance, driven by significantly improved net price and mid-single digit prescription growth for LINZESS, positioning us well to achieve our full-year 2026 financial guidance,” said Tom McCourt, chief executive officer of Ironwood. “We expect strong first quarter revenue to result in significant operating cash flows in the second quarter of 2026, which will help support repayment of our 2026 convertible notes at maturity in June.”
LINZESS, Ironwood’s gastrointestinal treatment developed in collaboration with AbbVie, generated U.S. net sales of $272.5 million in the first quarter, up 97% from $138.5 million a year earlier. Ironwood said the increase was driven by improved net pricing and 5% growth in prescription demand.
Ironwood recorded $104.2 million in collaboration revenue related to U.S. LINZESS sales, compared with $38.8 million in the first quarter of 2025. Net profit for the U.S. LINZESS brand collaboration, after commercial and research and development expenses, rose to $204.7 million from $65.9 million a year earlier.
The company said the U.S. Food and Drug Administration accepted and granted priority review to a supplemental New Drug Application for LINZESS as a treatment for functional constipation in children ages 2 to 5. The agency set a Prescription Drug User Fee Act date of May 24.
Ironwood also said it remains on track to begin site initiations in the second quarter for STARS-2, a confirmatory Phase 3 clinical trial of apraglutide in patients with short bowel syndrome with intestinal failure. Apraglutide is a once-weekly, long-acting synthetic GLP-2 analog being developed for rare gastrointestinal diseases.
“We remain on track for site initiation for the confirmatory STARS-2 Phase 3 clinical trial in the second quarter,” said Michael Shetzline, chief medical officer, senior vice president and head of research and drug development at Ironwood. “Building on the positive results from STARS, we believe that the highly potent, selective, and long-acting pharmacologic properties of apraglutide have the potential to drive best-in-class efficacy and tolerability with once-weekly dosing and redefine the standard of care in SBS-IF. Importantly, the long-term data generated to date show compelling enteral autonomy outcomes, with rapid and sustained reductions in parenteral support over time.”
The planned STARS-2 trial is expected to be a 24-week global, randomized, double-blind, placebo-controlled study. Its primary endpoint will measure relative change from baseline in actual weekly parenteral support volume.
Ironwood ended the quarter with $220.5 million in cash and cash equivalents, compared with $215.5 million at the end of 2025. The company generated $5.1 million in cash from operations during the quarter and had $385 million outstanding on its revolving credit facility as of March 31.
For 2026, Ironwood continues to expect U.S. LINZESS net sales of $1.125 billion to $1.175 billion, total revenue of $450 million to $475 million and adjusted EBITDA of more than $300 million.
