Ardelyx Launching IBSRELA® Second Quarter of 2022

- IBSRELA (tenapanor) the first and only NHE3 inhibitor approved for treatment of IBS-C in adults

- IBSRELA potential peak net revenue greater than $500 million annually

- Large and established IBS-C market in need of new therapeutic options

- Small specialty sales organization and focused digital marketing to target high prescribers and dissatisfied patients

- Company continues to pursue approval of tenapanor in hyperphosphatemia

- Company to host conference call today at 8:00 AM ET

FREMONT, Calif. and WALTHAM, Mass., Nov. 30, 2021 /PRNewswire/ -- Ardelyx, Inc. (Nasdaq: ARDX), a specialty biopharmaceutical company founded with a mission to discover, develop and commercialize innovative first-in-class medicines that meet significant unmet medical needs, today announced plans to launch IBSRELA, the company's approved treatment for irritable bowel syndrome with constipation (IBS-C) in adults, in the second quarter of 2022.

Mike Raab, president and chief executive officer of Ardelyx, stated, "Over the last five years, the IBS-C market has grown to be sizeable and concentrated, with 9,000 high-writing physicians accounting for approximately 50% of the almost five million prescriptions written annually for drugs indicated for the treatment of IBS-C. This market is ripe for the entry of a novel therapeutic option like IBSRELA, as existing therapies do not adequately address all patient treatment needs. Our market research has clearly shown that treating physicians recognize the need for new therapeutic alternatives to address the unmet medical needs of patients currently managed for IBS-C. That same research demonstrates high interest in, and intent to prescribe, IBSRELA for a subset of patients. By capturing even a modest share, in the mid to high single-digit of this large market, IBSRELA has the potential to generate at least $500 million in peak annual net revenue. We will use the next few months to build commercial inventory and prepare the market for a second-quarter 2022 launch. We believe we have a clear line of sight to breakeven and ultimate profitability for the product, which we expect will create significant shareholder value."

William Chey, M.D., Nostrant Professor of Medicine at the University of Michigan School of Medicine, added, "It is now widely recognized that while people with IBS-C present with similar symptoms, it is a disorder of heterogeneous pathogenesis. Therefore, while there has been much improvement in our treatment of patients with IBS-C over the last two decades with the introduction and broad adoption of GC-C agonists, it should be no surprise that many patients continue to suffer. There is a need for innovation. The launch of IBSRELA, as a first-in-class NHE3 inhibitor, is exciting, as it offers a unique mechanism of action with compelling clinical data, providing physicians with an important new tool to advance the care of patients with IBS-C."

"IBSRELA, with its first-in-class mechanism and strong clinical data package, is an important new addition to the IBS-C treatment armamentarium," said Laura A. Williams, M.D., M.P.H., chief medical officer of Ardelyx. "The approval of IBSRELA was based on two successful Phase 3 trials involving over 1,200 patients with IBS-C. Both trials met their primary and most secondary endpoints. Additionally, in both trials, improvements from baseline in average weekly bowel movements and abdominal pain were observed by Week 1, with improvement sustained through the end of treatment. IBSRELA can play a meaningful role in the treatment of patients suffering from IBS-C."

"As we work to bring IBSRELA to patients, we remain intent on pursuing approval of tenapanor for hyperphosphatemia through the formal dispute resolution process with the FDA, and as a commercial facing organization, if approved, we will be well-positioned to bring this novel therapy to patients," said Mike Raab, president and chief executive officer of Ardelyx.

Conference Call Information

The company will host a conference call today, November 30, 2021 at 8:00 AM ET to discuss the plans to launch IBSRELA for the treatment of IBS-C. To participate in the conference call, please call (855) 296-9612 (toll-free) or (920) 663-6277 (toll) and reference call ID number 2977157. A webcast of the call can also be accessed by visiting the Investor page of the company's website www.ardelyx.com and will be available on the website for 30 days following the call.

IMPORTANT SAFETY INFORMATION

CONTRAINDICATIONS

• IBSRELA is contraindicated in patients less than 6 years of age due to the risk of serious dehydration.
• IBSRELA is contraindicated in patients with known or suspected mechanical gastrointestinal obstruction.

WARNINGS AND PRECAUTIONS

Risk of Serious Dehydration in Pediatric Patients

• IBSRELA is contraindicated in patients below 6 years of age. The safety and effectiveness of IBSRELA in patients less than 18 years of age have not been established. In young juvenile rats (less than 1 week old; approximate human age equivalent of less than 2 years of age), decreased body weight and deaths occurred, presumed to be due to dehydration, following oral administration of tenapanor. There are no data available in older juvenile rats (human age equivalent 2 years to less than 12 years).
• Avoid the use of IBSRELA in patients 6 years to less than 12 years of age. Although there are no data in older juvenile rats, given the deaths in younger rats and the lack of clinical safety and efficacy data in pediatric patients, avoid the use of IBSRELA in patients 6 years to less than 12 years of age.

Diarrhea

Diarrhea was the most common adverse reaction in two randomized, double-blind, placebo-controlled trials of IBS-C. Severe diarrhea was reported in 2.5% of IBSRELA-treated patients.  If severe diarrhea occurs, suspend dosing and rehydrate patient.

MOST COMMON ADVERSE REACTIONS

The most common adverse reactions in IBSRELA-treated patients (incidence ≥2% and greater than placebo) were: diarrhea (16% vs 4% placebo), abdominal distention (3% vs