Exhibit 99.1

FOR IMMEDIATE RELEASE  

Ironwood Pharmaceuticals Reports Fourth Quarter and Full Year 2021 Results; LINZESS® (linaclotide) Achieves Blockbuster Status as U.S. Net Sales Exceed $1 Billion in 2021

– 2021 total revenue of $414 million, driven primarily by $400 million in U.S. LINZESS
collaboration revenue –

– 2021 GAAP net income of $528 million, includes a $338 million non-recurring income
tax benefit related to the release of the valuation allowance against the majority of the
company’s deferred tax assets in Q2 2021 –

– 2021 adjusted EBITDA of $234 million;
ended 2021 with $620 million in cash and cash equivalents –

– Pursuing two areas of unmet medical need with initiation of clinical studies for IW-3300 for the
treatment of visceral pain conditions, and CNP-104 for the treatment of primary biliary
cholangitis (PBC) –

BOSTON, Mass., February 17, 2022 — Ironwood Pharmaceuticals, Inc. (Nasdaq: IRWD), a GI-focused healthcare company, today reported its fourth quarter and full year 2021 results.

“The tremendous progress we made against our strategic priorities last year puts Ironwood in a solid position as we begin a new year,” said Tom McCourt, chief executive officer of Ironwood. “I am proud to share that LINZESS has earned blockbuster brand status with more than $1 billion in U.S. net sales in 2021, an extraordinary accomplishment for our company. I am also excited about what’s to come in 2022, as we strive to continue to execute on our key priorities of maximizing LINZESS growth via commercial innovation and lifecycle management, while also seeking to strengthen our innovative GI pipeline and focusing on delivering sustained profits and generating cash flow.”

“Bringing new treatments to GI patients remains a key priority and our team has been working hard to advance our pipeline,” said Mike Shetzline, chief medical officer, senior vice president and head of research and drug development. “We are pleased to announce that we have initiated the IW-3300 clinical study, which will evaluate the safety and tolerability of this potentially first-in-class treatment for visceral pain conditions. Combined with the initiation of the CNP-104 clinical study by COUR for primary biliary cholangitis, we are energized about the progress of our pipeline.”

Fourth Quarter and Full Year 2021 Financial Highlights¹

(in thousands, except for per share amounts)

Fourth Quarter and Full Year 2021 Corporate Highlights

U.S. LINZESS

IW-3300

CNP-104

Leadership Changes

Fourth Quarter and Full Year 2021 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 2022.

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 17, 2022 to discuss its fourth quarter and full year 2021 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 17, 2022 running through 11:59 p.m. Eastern Time on March 3, 2022. 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) 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.

We routinely post information that may be important to investors on our website at www.ironwoodpharma.com. In addition, follow us on Twitter and on LinkedIn.

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

LINZESS (linaclotide) is indicated in adults for the treatment of both irritable bowel syndrome with constipation (IBS-C) and chronic idiopathic constipation (CIC).

IMPORTANT SAFETY INFORMATION

Contraindications

Warnings and Precautions

Pediatric Risk

Diarrhea

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

Please see full Prescribing Information including Boxed Warning:

http://www.allergan.com/assets/pdf/linzess_pi

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. 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; the Ironwood’s ability to drive growth and profitability; the demand, development, commercial availability and commercial potential of linaclotide and the drivers, timing, impact and results thereof; the potential indications for, and benefits of, linaclotide; and our financial performance and results, and guidance and expectations related thereto, including expectations related to LINZESS U.S. net sales growth, total revenue and adjusted EBITDA in 2022; our plans to maximize LINZESS growth via commercial innovation and lifecycle management, to strengthen our innovative GI pipeline and to deliver sustained profits and generate cash flow; the potential of IW-3300 to be a first-in-class treatment of visceral pain conditions and the size of the IC/BPS and endometriosis populations; the size of estimated U.S. population affected by PBC; and the potential of CNP-104 to be the first PBC disease modifying therapy . 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 statement. Applicable risks and uncertainties include those related to the effectiveness of development and commercialization efforts by us and our partners; preclinical and clinical development, manufacturing and formulation development of linaclotide, CNP-104 and our product candidates; the risk that clinical programs and studies may not progress or develop as anticipated, including that studies are delayed or discontinued for any reason, such as safety, tolerability, enrollment, manufacturing, economic or other reasons; the risk that findings from our completed nonclinical and clinical studies may not be replicated in later studies; the risk that we or our partners are unable to obtain, maintain or manufacture sufficient LINZESS or our product candidates, or otherwise experience difficulties with respect to supply or manufacturing; the efficacy, safety and tolerability of linaclotide and our product candidates; the risk that the therapeutic opportunities for LINZESS or our product candidates are not as we expect; decisions by regulatory and judicial authorities; the risk we may never get additional patent protection for linaclotide and other product candidates, that patents for linaclotide or other products may not provide adequate protection from competition, or that we are not able to successfully protect such patents; the risk that we are unable to manage our expenses or cash use, or are unable to commercialize our products as expected; the risk that we may elect to not exercise our option to acquire the exclusive license for CNP-104; the risk that the development of either CNP-104 and/or IW-3300 is not successful or that any of our product candidates is not successfully commercialized; outcomes in legal proceedings to protect or enforce the patents relating to our products and product candidates, including abbreviated new drug application litigation; the risk that financial and operating results may differ from our projections; developments in the intellectual property landscape; challenges from and rights of competitors or potential competitors; the risk that our planned investments do not have the anticipated effect on our company revenues; developments in accounting guidance or practice; Ironwood’s or AbbVie’s accounting practices, including reporting and settlement practices as between Ironwood and AbbVie; the risk that we are unable to manage our expenses or cash use, or are unable to commercialize our products as expected; the impact of the COVID-19 pandemic; and the risks listed under the heading “Risk Factors” and elsewhere in Ironwood’s Quarterly Report on Form 10-Q for the quarter ended September 30, 2021, and in our subsequent Securities and Exchange Commission (the “SEC”) filings.

SOURCE: Ironwood Pharmaceuticals, Inc.

Investors:

Matt Roache, 617-621-8395

mroache@ironwoodpharma.com

Media:

Beth Calitri, 978-417-2031

bcalitri@ironwoodpharma.com

Condensed Consolidated Balance Sheets

(In thousands)

(unaudited)

Condensed Consolidated Statements of Income

(In thousands, except per share amounts)

(unaudited)

Reconciliation of GAAP Results to Non-GAAP Financial Measures

(In thousands, except per share amounts) (unaudited)

A reconciliation between net income on a GAAP basis and on a non-GAAP basis is as follows:

A reconciliation between basic net income per share on a GAAP basis and on a non-GAAP basis is as follows:

A reconciliation between diluted net income per share on a GAAP basis and on a non-GAAP basis is as follows:

Reconciliation of GAAP Net Income to Adjusted EBITDA

(In thousands)

(unaudited)

A reconciliation of GAAP net income to adjusted EBITDA:

U.S. LINZESS Commercial Collaboration¹

Revenue/Expense Calculation

(In thousands)

(unaudited)

¹ Ironwood collaborates with AbbVie on the development and commercialization of linaclotide in North America. Under the terms of the collaboration agreement, Ironwood receives 50% of the net profits and bears 50% of the net losses from the commercial sale of LINZESS in the U.S. The purpose of this table is to present calculations of Ironwood’s share of net profit (loss) generated from the sales of LINZESS in the U.S. and Ironwood’s collaboration revenue/expense; however, the table does not present the research and development expenses related to LINZESS in the U.S. that are shared equally between the parties under the collaboration agreement. Please refer to the table at the end of this press release for net profit for the U.S. LINZESS brand collaboration with AbbVie.

² In connection with its acquisition of Allergan in the second quarter of 2020, AbbVie recast historically reported LINZESS U.S. net sales (previously reported by Allergan) for periods between January 1, 2019 and March 31, 2020, to conform to AbbVie’s revenue recognition accounting policies and reporting conventions. As a result, certain of the rebates and discounts that were previously classified within LINZESS U.S. net sales have been reclassified as LINZESS U.S. commercial costs, expenses and other discounts within Ironwood’s calculation of collaborative arrangements revenue. Following March 31, 2020, such rebates and discounts continue to be classified as LINZESS U.S. commercial costs, expenses and other discounts. This recast did not result in any change to Ironwood’s historically reported collaborative arrangements revenue or collaborative arrangements revenue policy. Ironwood continues to record collaborative arrangements revenue based on actual settlement payments from AbbVie.

³ Includes certain discounts recognized and cost of goods sold incurred by AbbVie; also includes selling, general and administrative expenses incurred by AbbVie and Ironwood that are attributable to the cost-sharing arrangement between the parties, including the adjustment to selling expenses incurred throughout 2020 and recorded in the fourth quarter of 2020.

⁴ Commercial margin is defined as commercial profit on sales of LINZESS as a percent of total LINZESS U.S. net sales. Ironwood has recalculated commercial margin in connection with AbbVie’s recast of historically reported LINZESS U.S. net sales (previously reported by Allergan).

⁵ Ironwood has recalculated its share of net profit on sales of LINZESS in the U.S. to conform with AbbVie’s recast of historically reported LINZESS U.S. net sales (previously reported by Allergan).

⁶ Includes Ironwood’s selling, general and administrative expenses attributable to the cost-sharing arrangement with AbbVie. Excludes $0.3 million and $0.6 million for the years ended December 31, 2021 and 2020, respectively, related to patent prosecution and patent litigation costs recognized in connection with the collaboration agreement with AbbVie.

US LINZESS Full Brand Collaboration¹

Revenue/Expense Calculation

(In thousands)

(unaudited)

¹ Ironwood collaborates with AbbVie on the development and commercialization of linaclotide in North America. Under the terms of the collaboration agreement, Ironwood receives 50% of the net profits and bears 50% of the net losses from the commercial sale of LINZESS in the U.S. The purpose of this table is to present calculations of the total net profit (loss) generated from the sales of LINZESS in the U.S., including the commercial costs and expenses and the research and development expenses related to LINZESS in the U.S. that are shared equally between the parties under the collaboration agreement.

² In connection with its acquisition of Allergan in the second quarter of 2020, AbbVie recast historically reported LINZESS U.S. net sales (previously reported by Allergan) for periods between January 1, 2019 and March 30, 2020, to conform to AbbVie’s revenue recognition accounting policies and reporting conventions. As a result, certain of the rebates and discounts that were previously classified within LINZESS U.S. net sales have been reclassified as LINZESS U.S. commercial costs, expenses and other discounts within Ironwood’s calculation of collaborative arrangements revenue. Following March 31, 2020, such rebates and discounts continue to be classified as LINZESS U.S. commercial costs, expenses and other discounts.

³ Includes certain discounts recognized and cost of goods sold incurred by AbbVie; also includes selling, general and administrative expenses incurred by AbbVie and Ironwood that are attributable to the cost-sharing arrangement between the parties, including the adjustment to selling expenses incurred throughout 2020 and recorded in the fourth quarter of 2020.

⁴ R&D expenses related to LINZESS in the U.S. are shared equally between Ironwood and AbbVie under the collaboration agreement.

⁵ Ironwood has recalculated its share of net profit on sales of LINZESS in the U.S. to conform with AbbVie’s recast of historically reported LINZESS U.S. net sales (previously reported by Allergan).