Ironwood Pharmaceuticals Reports Strong Third Quarter 2025 Results; Raises Full Year 2025 Financial Guidance - LINZESS (Iinaclotide) U.S. net sales of $315 million in Q3 2025, an increase of 40% yea

Ironwood Pharmaceuticals

Reports Strong Third Quarter 2025 Results; Raises Full Year 2025 Financial Guidance

- LINZESS (Iinaclotide)

U.S. net sales of $315 million in Q3 2025, an increase of 40% year-over-year; EUTRx demand growth increased 12% year-over-year -

net income of $40 million and adjusted EBITDA of $82 million in Q3 2025; ended Q3 2025 with $140 million in cash and cash equivalents

full-year 2025 LINZESS U.S. net sales guidance to $860 - $890 million; total revenue guidance to $290 - $310 million and adjusted EBITDA

guidance to greater than $135 million -

LINZESS as the first drug for the treatment of children 7 years and older with irritable bowel syndrome with constipation (IBS-C) -

BOSTON, Mass., November 10,

2025 - 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 third quarter 2025 results and recent business

"LINZESS delivered a strong third-quarter

performance, driven by accelerated double-digit prescription demand growth combined with improved net pricing, which prompted us to raise

our full-year 2025 financial guidance. Importantly, we expect our strong third-quarter revenue will result in substantial fourth-quarter

cash flows, which will strengthen our financial position, enable us to reduce our debt and maintain compliance with debt covenants over

the coming quarters," said Tom McCourt, chief executive officer of Ironwood.

"As part of our ongoing commitment

to patients, we continue to seek ways to expand the clinical utility of LINZESS. This month, the FDA approved LINZESS for the treatment

of IBS-C in patients 7 years of age and older. We also remain focused on advancing the apraglutide program toward a confirmatory Phase

3 trial, with plans to align on a trial design with the FDA later this year. Pending that alignment, we expect to initiate a Phase 3

confirmatory study in the first half of 2026. In addition, we continue to review strategic alternatives to maximize shareholder value

and look forward to providing an update on that process as appropriate," added Tom McCourt.

Quarter 2025 Financial Highlights1

(in thousands, except for per share

1Refer to the Reconciliation

of GAAP Results to Non-GAAP Financial Measures table and to the Reconciliation of GAAP Net Income 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

third quarter of 2024 include a $5.8 million increase to collaborative arrangement revenues as a result of an adjustment recorded for

Ironwood's estimate of LINZESS gross-to-net reserves as of September 30, 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. 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, third quarter 2024 Adjusted EBITDA has also been updated to

reflect this updated definition.

Corporate Highlights

collaborative arrangements revenue includes reimbursement from AbbVie for a portion of Ironwood's commercial expenses related to

sales of LINZESS in the U.S. The FY2025 total revenue guidance accounts for the impact of the reduction to Ironwood's commercial

expenses and corresponding reimbursement from AbbVie due to Ironwood's strategic reorganization announced in January 2025.

2 Adjusted EBITDA is

calculated by subtracting restructuring expenses, net interest expense, income taxes, depreciation and amortization and stock-based compensation,

from GAAP net income. 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 purposes of this guidance, we have assumed that Ironwood will not incur material

expenses related to business development activities in 2025. 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.

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

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 6 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