Ironwood Pharmaceuticals Maintains FY 2025 Financial Guidance and Announces FY 2026 Financial Guidance - Expects full-year 2026 LINZESS U.S. net sales of $1.125 to $1.175 billion; total revenues of

Ironwood Pharmaceuticals

Maintains FY 2025 Financial Guidance and Announces FY 2026 Financial Guidance

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 -

Q4 2025 with greater than $200 million in cash and cash equivalents -

BOSTON, Mass., January 2, 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 announced financial guidance for full year 2026.

"Throughout 2025, we made significant

progress in maximizing LINZESS while delivering sustained profits and cash flows in an effort to strengthen our financial position and

maintain compliance with debt covenants over the coming quarters," said Tom McCourt, chief executive officer of Ironwood. "As

we close 2025, we are on track to achieve the low-end of our full-year LINZESS U.S. net sales and total revenue guidance ranges and ended

the fourth quarter with greater than $200 million in cash and cash equivalents. Also, in the fourth quarter we met with the FDA to align

on a confirmatory Phase 3 trial design of apraglutide for the treatment of short bowel syndrome with intestinal failure (SBS-IF). Based

on this meeting, we are on track to initiate a confirmatory trial in the first half of 2026 and expect to provide details on the trial

design in our fourth quarter and full-year 2025 update later this quarter."

"In 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 guidance demonstrates the significant progress we've made to deliver on these priorities to help drive value for shareholders

moving forward. Effective January 1, 2026, the LINZESS list price has been lowered in response to evolving health care dynamics

and to support ongoing patient access. In turn, we expect higher net sales in 2026 for LINZESS year-over-year, specifically driven by

the elimination of the inflationary component of statutory required rebates across channels, including Medicaid, due to the decrease

in list price. In conjunction with the anticipated increased net sales, we expect our continued focus on disciplined expense management

to result in greater than $300 million in adjusted EBITDA in 2026. Finally, we continue to progress our previously announced strategic

alternatives review in an effort to maximize shareholder value and look forward to providing further updates as appropriate," added

Ironwood is maintaining its previous

FY 2025 financial guidance and is providing FY 2026 financial guidance.

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 and 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.

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 adults with 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

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.

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 and

for the treatment of chronic idiopathic constipation (CIC) in adults and for the treatment of functional constipation (FC) in children

and adolescents 6 to 17 years of age.

IMPORTANT SAFETY INFORMATION

Warnings and Precautions

Common Adverse Reactions (incidence

2% and greater than placebo)

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

Forward-Looking Statements

This press release contains forward-looking

statements within the meaning of the Private Securities Litigation Reform Act of 1995. Investors are cautioned not to place undue reliance

on these forward-looking statements, including statements about Ironwood's ability to execute on its mission; Ironwood's

strategy, business, financial position and operations; Ironwood's ability to drive growth and profitability; the commercial potential

of LINZESS; Ironwood's financial performance and results, and guidance and expectations related thereto; LINZESS prescription demand

growth, LINZESS U.S. net sales growth, total revenue and adjusted EBITDA in 2025 and 2026; our belief that the 2026 financial guidance

demonstrates a significant progress made to help drive value for shareholders; our plan to continue to progress apraglutide and initiate

a confirmatory Phase 3 trial and our expectation and timing to provide additional details on the trial design and to initiate such trial;

and the status of the strategic alternatives review and timing to provide an update. 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 statements. Applicable risks and uncertainties include those related to the effectiveness of development and commercialization