Ironwood Pharmaceuticals Reports Fourth Quarter and Full Year 2022 Results - 2022 GAAP and non-GAAP net income of $175 million - - 2022 adjusted EBITDA of $252 million; ended 2022 with $656 million

Ironwood Pharmaceuticals Reports Fourth Quarter

and Full Year 2022 Results

- 2022 GAAP and non-GAAP net income of

- 2022 adjusted EBITDA of $252 million;

ended 2022 with $656 million in cash and cash equivalents -

- FDA granted priority review to the

sNDA for LINZESS (linaclotide) for the treatment of functional constipation in pediatric patients aged 6 to 17 with a PDUFA date

in the second quarter of 2023 -

BOSTON, Mass., February 16,

2023 - Ironwood Pharmaceuticals, Inc. (Nasdaq: IRWD), a GI-focused healthcare company, today reported its

fourth quarter and full year 2022 results and recent business performance.

"We performed well and made important progress across our strategic

priorities in 2022," said Tom McCourt, chief executive officer of Ironwood. "While full year LINZESS U.S. net sales growth

came in lower than our expectations for 2022 primarily due to inventory fluctuations in the retail channel, we are encouraged by continued

robust prescription demand and focused expense management, which helped us deliver our adjusted EBITDA guidance of over $250 million.

We ended the year with a strong balance sheet, positioning us well to continue to invest in LINZESS as a growth brand and actively pursue

highly differentiated GI assets to add to our portfolio. Looking ahead in 2023, we remain committed to further advancing our strategic

priorities, unlocking new opportunities for LINZESS, and strengthening and progressing our innovative GI portfolio. We anticipate a number

of exciting milestones this year, and believe Ironwood is well positioned to deliver long term growth and value to patients and shareholders."

Fourth Quarter and Full Year 2022 Financial Highlights1

(in thousands, except for per share amounts)

Fourth Quarter and Full Year 2022 Corporate Highlights

Fourth Quarter and Full Year 2022 Financial Results

1 Adjusted EBITDA is calculated by subtracting mark-to-market

adjustments on derivatives related to Ironwood's 2022 Convertible Notes, restructuring expenses, net interest expense, income taxes,

depreciation and amortization from GAAP net income. For purposes of this guidance, Ironwood has assumed that it will not incur material

expenses related to business development activities in 2023.

Non-GAAP Financial Measures

Ironwood presents non-GAAP net

income and non-GAAP net income per share to exclude the impact of net gains and losses on derivatives related to Ironwood's

2022 Convertible Notes that are required to be marked-to-market, restructuring expenses, and the release of the

company's valuation allowance against the majority of deferred tax assets in the second quarter of 2021. 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 mark-to-market adjustments on derivatives related to Ironwood's

2022 Convertible Notes, restructuring expenses, net interest expense, income taxes, depreciation and amortization from GAAP net income.

The adjustments are made on a similar basis as described above related to non-GAAP net income, 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 and non-GAAP net income

per share to GAAP net income and GAAP net income per share, respectively, and for a reconciliation of adjusted EBITDA to GAAP net income,

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, February 16, 2023 to discuss its fourth quarter and full year 2022 results

and recent business activities. Individuals interested in participating in the call should dial (888) 330-2384 (U.S. and Canada) or (240)

789-2701 (international) using conference ID number and event passcode 4671230. To access the webcast, please visit the Investors section

of Ironwood's website at www.ironwoodpharma.com at least 15 minutes prior to the start of the call to ensure adequate time for

any software downloads that may be required. The call will be available for replay via telephone starting at approximately 11:30 a.m. Eastern

Time on February 16, 2023, running through 11:59 p.m. Eastern Time on March 2, 2023. To listen to the replay, dial

(800) 770-2030 (U.S. and Canada) or (647) 362-9199 (international) using conference ID number 4671230. The archived webcast will be available

on Ironwood's website for 14 days beginning approximately one hour after the call has completed.

About Ironwood Pharmaceuticals

Ironwood Pharmaceuticals (Nasdaq: IRWD), an S&P

SmallCap 600 company, is a leading gastrointestinal (GI) healthcare company on a mission to advance the treatment of GI diseases

and redefine the standard of care for GI patients. We are pioneers 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).

Under the guidance of our seasoned industry leaders, we continue to build upon our history of GI innovation and challenge what has been

done before to shape what the future holds. We keep patients at the heart of our R&D and commercialization efforts to reduce the

burden of GI diseases and address significant unmet needs.

Founded in 1998, Ironwood Pharmaceuticals is

headquartered in Boston, Massachusetts.

routinely post information that may be important to investors on our website at www.ironwoodpharma.com.

About LINZESS (linaclotide)

LINZESS is the #1 prescribed

brand in the U.S. for the treatment of adult 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, constipation, and overall abdominal symptoms of bloating, discomfort and pain associated with

IBS-C, as well as the constipation, infrequent stools, hard stools, straining, and incomplete evacuation associated with CIC. The recommended

dose is 290 mcg for IBS-C patients and 145 mcg for CIC patients, with a 72-mcg dose approved for use in CIC depending on individual patient

presentation or tolerability. LINZESS should be taken at least 30 minutes before the first meal of the day.

LINZESS is contraindicated in

pediatric patients less than 2 years of age. In neonatal mice, linaclotide increased fluid secretion as a consequence of age-dependent

elevated GC-C agonism resulting in 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. The safety and effectiveness of LINZESS in patients less than 18 years of age have not been established.

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.

LINZESS Important Safety Information

INDICATIONS AND USAGE