CymaBay Therapeutics Presents Positive PBC Data at the International Liver Congress™ 2022

• Seladelpar Treatment of PBC Patients for Two Years Predicts Improved Transplant-Free Survival

NEWARK, Calif., June 22, 2022 (GLOBE NEWSWIRE) — CymaBay Therapeutics, Inc. (NASDAQ: CBAY), a clinical-stage biopharmaceutical company focused on developing therapies for liver and other chronic diseases with high unmet need, today announced encouraging seladelpar data in patients with primary biliary cholangitis (PBC) that are being presented at The International Liver Congress™ 2022 of the European Association for the Study of Liver (EASL) which will be held in London, UK from June 22^nd – 26^th.

In a poster presentation titled, “Seladelpar Treatment of Patients With Primary Biliary Cholangitis (PBC) For 2 Years Improves the GLOBE PBC Score and Predicts Improved Transplant-Free Survival,”¹ Bettina Hansen, PhD, Associate Professor Toronto Centre for Liver Disease, University of Toronto, will be reporting the improvement in GLOBE score following seladelpar treatment over two years and predicted transplant-free survival. The GLOBE score is a validated risk-assessment tool providing an estimate of transplant-free survival for patients with PBC.

Patients with PBC having an incomplete response or intolerance to UDCA (defined as alkaline phosphatase (ALP) ≥ 1.67xULN) had completed an open-label one-year phase 2 study of daily oral seladelpar therapy (NCT: 02955602). After 1 year, patients were eligible for an open label long-term study (NCT: 03301506). Treatment of 50 patients with oral seladelpar 5 mg or 10 mg daily for 2 years resulted in a mean (SD) change from baseline in GLOBE score of -0.417 (0.269), resulting in a corresponding hazard ratio of 0.66 for transplantation or death compared to no prior treatment with seladelpar (baseline). The improvement in GLOBE score and predicted survival did not depend on age. However, an analysis of subpopulations of high risk patients by GLOBE score (> 0.3) revealed that while patients of all ages improved, the younger patients tended to have numerically greater improvements, although these differences did not achieve significance.

“These findings demonstrate that seladelpar treatment over 2 years resulted in a sustained decrease in GLOBE score for patients with PBC. These results provide an estimate of seladelpar’s treatment effect on transplant-free survival for patients with PBC supporting its continued long-term evaluation in patients with PBC,” said Dr. Bettina Hansen.

An oral presentation² by Dr. Bernd Schnabl, Professor of Medicine at the University of California San Diego, will describe the suppression of bile acid synthesis by seladelpar and reveal the role of FGF-21 signaling, a previously known regulator of bile acid synthesis. These results provide new insights into the anti-cholestatic mechanism of seladelpar.

Dr. Dennis Kim, Chief Medical Officer of CymaBay Therapeutics, commented, “We continue to be encouraged by the potential key role seladelpar can play in providing benefit to patients with PBC. We look forward to our continued collaboratation with our academic partners and investigators to further explore how this first and only delpar in development for the treatment of PBC can advance the care and quality of life for patients with PBC over time. We want to extend our sincere gratitude to the patients and investigators who have participated in our clinical studies and look forward to completing our RESPONSE global Phase 3 study for seladelpar in PBC.

Presentations at The International Liver Congress™ 2022 include:

Poster Presentations:

June 23^rd 9:00 – 18:30 BST
1529: ¹“Seladelpar Treatment of Patients With Primary Biliary Cholangitis (PBC) For 2 Years Improves the GLOBE PBC Score and Predicts Improved Transplant-Free Survival”
Bettina E. Hansen, Elaine Watkins, Ke Yang, Yun-Jung Choi, Charles A. McWherter, Gideon M. Hirschfield, for the Seladelpar Long-Term Study Investigators

June 24^th 9:00 – 18:00 BST
1518: “Comparative fibrosis-reducing activities of farnesoid X receptor (FXR), peroxisome-proliferator activated receptor delta (PPAR) and thyroid hormone receptor (THR) agonists in the carbon tetrachloride mouse model”
Edward Cable, Jeffrey Stebbins, Yun-Jung Choi, Jiangao Song, Prasad Manchem, Sanjay Pandey, Charles A. McWherter

Oral Presentation:

June 25^th 9:00 AM BST
2726: ²“The selective PPAR-delta agonist seladelpar suppresses bile acid synthesis by reducing hepatocyte CYP7A1 through the FGF21 pathway”
Tetsuya Kouno, Xiao Liu, Tatiana Kisseleva, Edward E. Cable, Bernd Schnabl

Congress attendees can visit CymaBay throughout the meeting at booth 93.

A full list of presentations can be found on The International Liver Congress ™ 2022 website.

The presentations will be made available on the CymaBay website.

About PBC
PBC is a rare, chronic inflammatory liver disease primarily affecting women (1 in 1,000) over the age of 40. 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 alkaline phosphatase (ALP) and total bilirubin. The most common early symptoms of PBC are itching (pruritus) and fatigue, which can be very debilitating for some patients. Progression of PBC is associated with an increased risk of liver cancer and liver-related mortality.

About Seladelpar
Seladelpar is a first-in-class oral, selective PPARδ agonist 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 acids 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 treatment for people with primary biliary cholangitis (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 www.cymabay.com and follow us on 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 of the disease and the potential benefits to patients 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.

For additional information about CymaBay visit www.cymabay.com.

Public Relations Contact:

Glenn Silver
Lazar-FINN Partners
(973) 818-8198
Glenn.silver@finnpartners.com

Investor Relations Contact:

Hans Vitzthum
LifeSci Advisors, LLC
(617) 430-7578
Hans@LifeSciAdvisors.com