Ironwood Pharmaceuticals Reports Fourth Quarter and Full Year 2025 Results; Achieves 2025 Financial Guidance and Reiterates Strong 2026 Outlook - LINZESS (linaclotide) EUTRx demand growth of 11% for

Ironwood Pharmaceuticals Reports Fourth Quarter

and Full Year 2025 Results; Achieves 2025 Financial Guidance and Reiterates Strong 2026 Outlook

- LINZESS (linaclotide)

EUTRx demand growth of 11% for full year 2025 year-over-year -

- 2025 Ironwood revenue of $296 million,

GAAP net income of $24 million and adjusted EBITDA of $138 million -

- Continue to expect

full-year 2026 LINZESS U.S. net sales of $1.125 to $1.175 billion; total revenues of $450 to $475 million and adjusted

EBITDA of greater than $300 million -

elements of confirmatory Phase 3 clinical trial design of apraglutide in short bowel syndrome with intestinal failure (SBS-IF) have been

finalized with site initiations expected to begin in the second quarter of 2026 -

BOSTON, Mass., February 25th,

2026 - 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 fourth quarter and full-year 2025 results and recent business performance.

"In 2025, LINZESS delivered 11% EUTRx demand growth year-over-year,

continuing to strengthen its position as the prescription market leader for the treatment of IBS-C and CIC, surpassing 5.7 million unique

patients treated since launch. Additionally, throughout 2025 our disciplined approach to expense management allowed us to navigate LINZESS

pricing headwinds, deliver $24 million in GAAP net income and $138 million in adjusted EBITDA and generate $127 million in cash flow from

operations," said Tom McCourt, chief executive officer of Ironwood. "Importantly, we ended 2025 with $215 million in cash

and cash equivalents, positioning Ironwood well for 2026."

we enter 2026, we remain focused on our core priorities of maximizing LINZESS, advancing apraglutide and delivering sustained profits

and cash flows. We believe our full-year 2026 financial guidance demonstrates the significant progress we've made across these priorities

and our ability to drive increasing shareholder value. In 2026, we expect increased LINZESS U.S. Net Sales and disciplined expense management

to drive greater than $300 million in adjusted EBITDA, enabling us to continue advancing apraglutide and reduce our debt to further strengthen

our financial position. We believe apraglutide has the potential to redefine

the standard of care for patients living with SBS-IF and look forward to initiating sites for the confirmatory Phase 3 clinical trial,

STARS-2, in the second quarter of this year. With an improved financial position, we now have a clear path to execute our strategy, and

we continue to evaluate all options to maximize shareholder value."

Fourth Quarter and Full Year 2025 Financial Highlights1

(in thousands, except for per share amounts)

1 Refer to the Reconciliation of GAAP Results to Non-GAAP

Financial Measures table and to the Reconciliation of GAAP Net Income (Loss) to Adjusted EBITDA table at the end of this press release.

Refer to Non-GAAP Financial Measures for additional information.

2 Figures presented for the fourth quarter of 2024 collaboration revenue to Ironwood includes a $7.2 million positive

adjustment to reflect Ironwood's estimate of LINZESS gross-to-net reserves as of December 31, 2024.

3 Adjusted EBITDA is calculated by subtracting restructuring expenses, net interest expense, income taxes, depreciation

and amortization and stock-based compensation, from GAAP net income (loss). The exclusion of stock-based compensation from Adjusted EBITDA

represents an update to our definition of Adjusted EBITDA, effective in the first quarter of 2025. For comparison purposes, fourth quarter

and full year 2024 Adjusted EBITDA have also been updated to reflect this updated definition.

Fourth Quarter and Full Year 2025 Corporate Highlights

Fourth Quarter and Full Year 2025 Financial Results

1 Ironwood's U.S. collaborative arrangements

revenue includes reimbursement from AbbVie for a portion of Ironwood's commercial expenses related to sales of LINZESS in the U.S.

2 Adjusted EBITDA is calculated by subtracting stock-based compensation, restructuring expenses, net interest expense,

income taxes, and depreciation and amortization, from GAAP net income (loss). For purposes of this guidance, we have assumed that Ironwood

will not incur material expenses related to business development activities in 2026. 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. 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.

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, restructuring expenses, and acquisition-related costs, all net

of tax effect. Non-GAAP adjustments are further detailed below:

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, restructuring expenses, net interest

expense, income taxes, depreciation and amortization, and acquisition-related costs from GAAP net income. 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 Wednesday, February 25th, 2026 to discuss its fourth quarter and full year 2025 results and recent business activities.

Individuals interested in participating in the call should dial (888) 596-4144 (U.S. and Canada) or (646) 968-2525 (international) using

conference ID number and event passcode 2530602. 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 Wednesday, February 25th,

2026, at approximately 11:30 a.m. Eastern Time, running through 11:59 p.m. Eastern Time on Wednesday, March 11, 2026.

To listen to the replay, dial (800) 770-2030 (U.S. and Canada) or (609) 800-9909 (international) using conference ID number 2530602.

The archived webcast will be available on Ironwood's website for 1 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

About Short Bowel Syndrome (SBS)

SBS is a serious and chronic condition where there is diminished absorptive capacity for fluids and/or

nutrients, sometimes requiring dependence on parenteral support to maintain health. SBS typically occurs because of extensive intestinal