Ironwood Pharmaceuticals Raises 2026 Full-Year Financial Guidance Building on Strong Second Quarter Results

– Raises full-year 2026 LINZESS^® (linaclotide) U.S. net sales guidance to $1.15 - $1.20 billion, representing greater than 30% increase year-over-year; Raises total revenue guidance to $460 - $485 million and adjusted EBITDA guidance to greater than $310 million –

– Q2 2026 LINZESS U.S. net sales of $282 million; $555 million year-to-date representing 44% year-over-year growth –

– Total revenue of $113 million, GAAP net income of $51 million and adjusted EBITDA of $83 million in Q2 2026; repaid $200 million convertible notes with cash on hand –

– Confirmatory Phase 3 STARS-2 trial of apraglutide in short bowel syndrome with intestinal failure (SBS-IF) now actively recruiting patients –

BOSTON--(BUSINESS WIRE)--Ironwood Pharmaceuticals, Inc. (Nasdaq: IRWD), a biotechnology company developing and commercializing life‑changing therapies for people living with gastrointestinal (GI) and rare diseases, today reported its second quarter 2026 results and recent business performance.

“Throughout the first half of the year, we have remained laser focused on meaningful execution of our three strategic priorities: maximizing LINZESS, advancing apraglutide, and delivering sustained profits and cash flows,” said Tom McCourt, chief executive officer of Ironwood. “We are pleased to report a second consecutive quarter of strong performance for LINZESS, fueled by improved net price and mid-single digit prescription demand growth which supported our decision to raise our full-year 2026 financial guidance. We also repaid our $200 million convertible notes during the quarter using cash on hand and remain committed to further debt reduction and strengthening our balance sheet through year end.”

“Importantly, we initiated STARS-2 and are actively recruiting patients in this confirmatory Phase 3 trial of apraglutide with the goal that it will be the first long-acting GLP-2 analog to market. Based on the positive Phase 3 STARS data and the confirmatory design of STARS-2, we are confident that apraglutide has the potential to be a best-in-class therapy for people with short bowel syndrome with intestinal failure, a condition with significant unmet need,” McCourt continued. “With Dr. Jeffrey Silber now serving as chief medical officer and head of research and drug development, his proven clinical development leadership further strengthens our ability to advance apraglutide and bring it to patients as quickly as possible.”

Second Quarter 2026 Financial Highlights¹

Second Quarter Corporate Highlights

U.S. LINZESS

• In May 2026, the U.S. Food and Drug Administration (FDA) approved the use of LINZESS in pediatric patients 2 years of age and older with functional constipation (FC). LINZESS remains the only FDA-approved prescription therapy for pediatric FC.
• Prescription Demand: Total LINZESS demand in the second quarter of 2026 was 59.8 million LINZESS capsules, a 4% increase compared to the second quarter of 2025, per IQVIA. Based on this performance, we raised our U.S. LINZESS net sales guidance, which now reflects a mid-single digit percentage demand growth.
• U.S. Brand Collaboration: LINZESS U.S. net sales are provided to Ironwood by its U.S. partner, AbbVie Inc. (“AbbVie”). LINZESS U.S. net sales were $282.3 million in the second quarter of 2026, a 14% increase compared to $248.0 million in the second quarter of 2025. Ironwood and AbbVie share equally in U.S. brand collaboration profits.
  • Q2 2026 LINZESS U.S. net sales growth year-over-year was driven by 4% demand growth and significantly improved net price due to elimination of inflationary rebates and favorable time-phasing of gross-to-net rebate reserves in the second quarter of 2026 relative to 2025.
  • LINZESS commercial margin was 78% in the second quarter of 2026, compared to 69% in the second quarter of 2025. See the U.S. LINZESS Full Brand Collaboration table at the end of this press release.
  • Net profit for the LINZESS U.S. brand collaboration, net of commercial and research and development (“R&D”) expenses, was $214.6 million in the second quarter of 2026, a 30% increase compared to $164.9 million in the second quarter of 2025. See the U.S. LINZESS Full Brand Collaboration table at the end of this press release.
• Collaboration Revenue to Ironwood: Ironwood recorded $110.0 million in collaboration revenue in the second quarter of 2026 related to sales of LINZESS in the U.S., a 28% increase compared to $85.7 million for the second quarter of 2025. See the U.S. LINZESS Commercial Collaboration table at the end of the press release.

Apraglutide

• Ironwood initiated and is actively recruiting patients for STARS-2, (NCT07742735) a confirmatory Phase 3 clinical trial of apraglutide for patients with SBS-IF dependent on parenteral support (“PS”), a severe chronic malabsorptive condition. STARS-2 is a 24-week global, randomized, double-blind, placebo-controlled trial. The primary endpoint is relative change from baseline in actual weekly PS volume. Secondary endpoints also to be measured at week 24 for the overall population include clinical response (defined as a 20% reduction in PS volume), number of days of PS per week, and enteral autonomy.
• Apraglutide is a once-weekly, long-acting synthetic glucagon-like peptide-2 (“GLP-2”) analog with the potential to treat a range of rare GI diseases in which GLP-2 can play a central role in addressing disease pathophysiology. Based on positive data generated from the STARS Phase 3 trial, Ironwood believes apraglutide has the potential to be a best-in-class therapeutic to improve the standard of care for adult patients with SBS who are dependent on PS, as the first and only GLP-2 to achieve a statistically significant reduction in weekly PS volume with once-weekly administration.
• In May 2026, during the 2026 Digestive Disease Week (DDW) conference, Ironwood presented data pooled from studies in the STARS clinical program - including the Phase 2 STARS Nutrition study, STARS Phase 3 randomized placebo-controlled study, and the ongoing open-label extension study STARS Extend. In this analysis, apraglutide showed a safety profile consistent with previous studies. These findings build on the positive data previously announced in 2024.

Corporate Updates

• In May, Ronald Silver, Ironwood’s Corporate Controller and Chief Accounting Officer, was appointed as Interim Chief Financial Officer, following the resignation of Gregory Martini.
• In July, Dr. Jeffrey Silber joined Ironwood as Chief Medical Officer and Head of Research and Drug Development, following the retirement of Dr. Michael Shetzline. With broad medical and scientific leadership expertise, Dr. Silber will lead Ironwood’s next phase of R&D strategy and execution.

Second Quarter 2026 Financial Results

• Total Revenue. Total revenue in the second quarter of 2026 was $113.0 million, compared to $85.2 million in the second quarter of 2025.
  • Total revenue in the second quarter of 2026 consisted of $110.0 million associated with Ironwood’s share of the net profits from the sales of LINZESS in the U.S., and $3.0 million in royalties and other revenue. Total revenue in the second quarter of 2025 consisted of $85.7 million associated with Ironwood’s share of the net profits from the sales of LINZESS in the U.S., and ($0.5) million in royalties and other revenue.
• Total Costs and Expenses. Total costs and expenses in the second quarter of 2026 were $33.7 million, compared to $39.9 million in the second quarter of 2025.
  • Total costs and expenses in the second quarter of 2026 consisted of $22.4 million in R&D expenses and $11.3 million in selling, general and administrative (“SG&A”) expenses. Total costs and expenses in the second quarter of 2025 consisted of $23.4 million in R&D expenses, $16.8 million in SG&A expenses, and ($0.3) million in restructuring expenses.
• Interest Expense. Interest expense was $7.2 million in the second quarter of 2026, in connection with Ironwood’s convertible senior notes, which were paid at maturity in June 2026, and revolving credit facility. Interest expense was $8.4 million in the second quarter of 2025 in connection with Ironwood’s convertible senior notes and revolving credit facility.
• Interest and Investment Income. Interest and investment income was $1.6 million in the second quarter of 2026 and $0.8 million in the second quarter of 2025.
• Other. Other income was insignificant in the second quarter of 2026 and in the second quarter of 2025 and pertained to a gain recorded for pension-related activities.
• Income Tax Expense. Ironwood recorded $22.4 million of income tax expense in the second quarter of 2026, the majority of which was non-cash, as Ironwood continues to utilize net operating losses to offset taxable income for federal purposes and in many states. Ironwood recorded $14.2 million of income tax expense in the second quarter of 2025, the majority of which was non-cash, as Ironwood continued to utilize net operating losses to offset taxable income for federal purposes and in many states.
• GAAP Net Income. GAAP net income was $51.3 million, or $0.31 per share (basic and diluted) in the second quarter of 2026, compared to GAAP net income of $23.6 million, or $0.15 per share (basic) and $0.14 per share (diluted) in the second quarter of 2025.
• Non-GAAP Net Income. Non-GAAP net income was $51.5 million, or $0.31 per share (basic and diluted), in the second quarter of 2026, compared to non-GAAP net income of $23.6 million, or $0.15 per share (basic) and $0.14 per share (diluted), in the second quarter of 2025.
  • Non-GAAP net income excludes the impact of amortization of acquired intangible assets, and net restructuring expenses, all net of tax effect. See Non-GAAP Financial Measures below.
• Adjusted EBITDA. Adjusted EBITDA was $83.0 million in the second quarter of 2026, compared to $50.1 million in the second quarter of 2025.
  • Adjusted EBITDA is calculated by subtracting stock-based compensation, net restructuring expenses, net interest expense, income taxes, depreciation and amortization, from GAAP net income. See Non-GAAP Financial Measures below.
• Cash Flow Highlights. Ironwood ended the second quarter of 2026 with $79.1 million of cash and cash equivalents, compared to $215.5 million of cash and cash equivalents at the end of 2025.
  • The outstanding principal balance on the revolving credit facility was $385.0 million as of June 30, 2026, with $165.0 million of remaining borrowing capacity available under the facility.
  • Ironwood generated $58.3 million in cash from operations in the second quarter of 2026, compared to $15.1 million in cash from operations in the second quarter of 2025.
  • Ironwood had $112.7 million in accounts receivable as of June 30, 2026, primarily related to second quarter 2026 collaboration revenues.
  • Ironwood repaid in full the $200 million aggregate principal amount of its 1.50% convertible senior notes at their scheduled maturity in June 2026 using available cash on hand.
• Ironwood 2026 Financial Guidance. Ironwood is raising its 2026 financial guidance and now expects:

Non-GAAP Financial Measures

Ironwood presents non-GAAP net income (loss) and non-GAAP net income (loss) per share to exclude amortization of acquired intangible assets, and net restructuring expenses, all net of tax effect. Non-GAAP adjustments are further detailed below:

• Amortization of acquired intangible assets are non-cash expenses arising in connection with the acquisition of VectivBio, which is considered to be non-recurring.
• Restructuring expenses are considered to be a non-recurring event as they are associated with distinct operational decisions. Restructuring expenses include costs associated with exit and disposal activities.
• Ironwood also presents adjusted EBITDA, a non-GAAP measure, as well as guidance on adjusted EBITDA. Adjusted EBITDA is calculated by subtracting stock-based compensation, net restructuring expenses, net interest expense, income taxes, depreciation and amortization from GAAP net income (loss). The adjustments are made on a similar basis as described above related to non-GAAP net income (loss), as applicable.

Management believes this non-GAAP information is useful for investors, taken in conjunction with Ironwood’s GAAP financial statements, because it provides greater transparency and period-over-period comparability with respect to Ironwood’s operating performance. These measures are also used by management to assess the performance of the business. Investors should consider these non-GAAP measures only as a supplement to, not as a substitute for or as superior to, measures of financial performance prepared in accordance with GAAP. In addition, these non-GAAP financial measures are unlikely to be comparable with non-GAAP information provided by other companies. For a reconciliation of non-GAAP net income (loss) and non-GAAP net income (loss) per share to GAAP net income (loss) and GAAP net income (loss) per share, respectively, and for a reconciliation of adjusted EBITDA to GAAP net income (loss), please refer to the tables at the end of this press release.

Ironwood does not provide guidance on GAAP net income or a reconciliation of expected adjusted EBITDA to expected GAAP net income because, without unreasonable efforts, it is unable to predict with reasonable certainty the non-GAAP adjustments used to calculate adjusted EBITDA. These adjustments are uncertain, depend on various factors and could have a material impact on GAAP net income for the guidance period.

Conference Call Information

Ironwood will host a conference call and webcast at 8:30 a.m. Eastern Time on Thursday, August 6^th, 2026, to discuss its second quarter results and recent business activities. Individuals interested in participating in the call should dial (888) 596-4144 (U.S.) or (646) 968-2525 (international) using conference ID number and event passcode 3647053. To access the webcast, please visit the Investors section of Ironwood’s website at www.ironwoodpharma.com. The call will be available for replay via telephone starting Thursday, August 6, 2026, at approximately 11:30 a.m. Eastern Time, running through 11:59 p.m. Eastern Time on Thursday, August 20, 2026. To listen to the replay, dial (800) 770-2030 (U.S. and Canada) using conference ID number 3647053. The archived webcast will be available on Ironwood’s website for one year beginning approximately one hour after the call has completed.

About Ironwood Pharmaceuticals

Ironwood Pharmaceuticals (Nasdaq: IRWD) is a biotechnology company developing and commercializing life-changing therapies for people living with gastrointestinal (GI) and rare diseases. Ironwood is advancing apraglutide, a next-generation, long-acting synthetic GLP-2 analog being developed for short bowel syndrome patients who are dependent on parenteral support. In addition, Ironwood has been a pioneer in the development of LINZESS® (linaclotide), the U.S. branded prescription market leader for the treatment of irritable bowel syndrome with constipation (IBS-C) or chronic idiopathic constipation (CIC). Building upon our history of innovation, we keep patients at the heart of our R&D and commercialization efforts to reduce the burden of 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.

About LINZESS (Linaclotide)

LINZESS® is the #1 prescribed brand in the U.S. for the treatment of 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 and constipation associated with IBS-C in adults and pediatric patients 7 years of age and older. LINZESS has also been shown to relieve constipation, infrequent stools, hard stools, straining and incomplete evacuation associated with CIC in adult patients. LINZESS relieves constipation in children and adolescents aged 2 to 17 years with functional constipation.

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 IBS-C in adults and pediatric patients 7 years of age and older, CIC in adults and functional constipation (FC) in pediatric patients 2 years of age and older. 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 Grand Life Sciences 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 irritable bowel syndrome with constipation (IBS-C) in adults and pediatric patients 7 years of age and older, chronic idiopathic constipation (CIC) in adults, and functional constipation (FC) in pediatric patients 2 years of age and older.

IMPORTANT SAFETY INFORMATION

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

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 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 adult patients with IBS-C or CIC treated with LINZESS 145 mcg or 290 mcg once daily, and in <1% of adult patients with CIC treated with LINZESS 72 mcg once daily. In pediatric patients, diarrhea was also the most common adverse reaction in clinical trials of patients 7 to 17 years of age with IBS-C and 6 to 17 years of age with FC treated with LINZESS. In two double-blind trials, diarrhea was reported in 4% of pediatric patients 6 to 17 years of age with FC treated with LINZESS 72 mcg once daily, and 7% and 8% of pediatric patients 7 to 17 years of age with IBS-C treated with LINZESS 145 mcg and 290 mcg once daily, respectively. In clinical trials, severe diarrhea was reported in one pediatric patient with FC treated with LINZESS 72 mcg once daily and in one pediatric patient with IBS-C treated with LINZESS at a dose higher than the recommended 145 mcg once daily dosage for IBS-C. If severe diarrhea occurs, dosing should be suspended and the patient rehydrated.

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

• In adult patients with IBS-C or CIC: diarrhea, abdominal pain, flatulence and abdominal distension.
• In pediatric patients 7 to 17 years of age with IBS-C and 6 to 17 years of age with FC: 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.

Forward-Looking Statements

This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995.

Investors and Media:
Chris Stamm
Vice President, Investor Relations and Communications
cstamm@ironwoodpharma.com

Investors:
Precision AQ
Stephanie Ascher
Stephanie.Ascher@precisionaq.com