CymaBay Initiates AFFIRM, a Phase 3b/4 Study Evaluating the Effect of Seladelpar on Clinical Outcomes in Patients with Cirrhosis due to Primary Biliary Cholangitis

AFFIRM is a unique event-driven, fixed-duration design intended to reduce the challenges for patient participation

Data will be used to support post-marketing regulatory requirements for seladelpar’s accelerated approval pathway

NEWARK, Calif., Sept. 21, 2023 (GLOBE NEWSWIRE) — CymaBay Therapeutics, Inc. (NASDAQ: CBAY), a biopharmaceutical company focused on innovative therapies for patients with liver and other chronic diseases, today announced the initiation of AFFIRM, a randomized, placebo-controlled confirmatory study to evaluate the effect of seladelpar on clinical outcomes in patients with compensated cirrhosis due to primary biliary cholangitis (PBC).

The AFFIRM study is planned to enroll approximately 192 patients with PBC who have compensated cirrhosis (Child-Pugh A or Child-Pugh B) based on prespecified clinical criteria. Patients will be randomly assigned using a 2:1 ratio to oral, once daily seladelpar or placebo for a fixed duration of three years. The primary outcome measure is the time from start of treatment to the first occurence of clinical events (all-cause death, liver transplant, hospitalization for other serious liver-related events, and progression to Child-Pugh C decompensated cirrhosis). Additional key outcomes include overall survival, liver transplant-free survival, and time to hospitalization for serious liver-related events.

Charles McWherter, Ph.D., Chief Scientific Officer and President of Research and Development at CymaBay, stated, “The AFFIRM study was initiated to characterize the efficacy and safety of seladelpar in a PBC population with advanced disease. It is designed to fulfill post-marketing requirements of the accelerated approval pathway for seladelpar to confirm its benefit on clinical outcomes. Over the past few years, we have had significant interactions with regulators to develop a study in the backdrop of many known operational and ethical challenges in conducting a placebo-controlled long-term outcomes study. We selected this population and design to establish the effect of seladelpar on clinical outcomes. We remain fully committed to meeting our scientific and regulatory commitments while prioritizing the health of people living with PBC.”

“The goal of therapy in patients with PBC is to prevent progression to end-stage liver disease and liver failure, however, carrying out placebo controlled outcomes trials is challenging due to the long natural history of PBC. I am pleased to learn that the AFFIRM study will aim to confirm the benefit of seladelpar in patients with PBC over a three year period, which is the shortest timeframe we have seen to date for a confirmatory trial,” said Dr. Kris V. Kowdley, Director of Liver Institute Northwest, and Professor at the Elson S. Floyd College of Medicine, Washington State University.

About PBC
PBC is a rare, chronic inflammatory liver disease primarily affecting women (1 in 1,000 women over the age of 40 or about 130,000 total people in the US). PBC is characterized by impaired bile flow (known as cholestasis) and the accumulation of toxic bile acids in the liver, leading to inflammation and destruction of the bile ducts within the liver and causing increased levels of ALP and total bilirubin. The most common early symptoms of PBC are pruritis (itching) and fatigue, which can be debilitating for some patients. Progression of PBC is associated with an increased risk of liver-related mortality.

About Seladelpar
Seladelpar, an investigational treatment for people with PBC, is a first-in-class oral, selective peroxisome proliferator-activated receptor (PPAR) delta agonist, or delpar, shown to regulate critical metabolic and liver disease pathways in indications with high unmet medical need. Preclinical and clinical data support its ability to regulate genes involved in bile acid synthesis, inflammation, fibrosis and lipid metabolism, storage, and transport.

About CymaBay
CymaBay Therapeutics, Inc. is a clinical-stage biopharmaceutical company focused on improving the lives of people with liver and other chronic diseases that have high unmet medical need through a pipeline of innovative therapies. Our deep understanding of the underlying mechanisms of liver inflammation and fibrosis, and the unique targets that play a role in their progression, have helped us receive breakthrough therapy designation (U.S. Food and Drug Administration), Priority Medicines status (European Medicines Agency) and orphan drug status (U.S. and Europe) for seladelpar, a first-in-class investigational treatment for people with PBC. Our evidence-based decision-making and commitment to the highest quality standards reflect our relentless dedication to the people, families, and communities we serve. To learn more, visit and follow us on X (formerly Twitter) and LinkedIn.

Cautionary Statements
Any statements made in this press release regarding the potential for seladelpar to treat PBC and potentially improve clinical symptoms or outcomes of the disease, the ability to enroll and/or complete the AFFIRM study, the potential benefits to patients and the future filing plans of CymaBay are forward-looking statements that are subject to risks and uncertainties. Actual results and the timing of events regarding the further development of seladelpar could differ materially from those anticipated in such forward-looking statements as a result of risks and uncertainties, which include, without limitation, risks related to: the success, cost and timing of any of CymaBay’s product development activities, including clinical trials; and effects observed in trials to date that may not be repeated in the future. Additional risks relating to CymaBay are contained in CymaBay’s filings with the Securities and Exchange Commission, including without limitation its most recent Annual Report on Form 10-K, its Quarterly Reports on Form 10-Q and other documents subsequently filed with or furnished to the Securities and Exchange Commission. CymaBay disclaims any obligation to update these forward-looking statements except as required by law.

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