CAMBRIDGE, Mass., Oct. 21, 2025 (GLOBE NEWSWIRE) -- Flare Therapeutics Inc. (FlareTx), a clinical-stage biotechnology company targeting transcription factors to discover precision medicines for oncology and other therapeutic areas, today announced that it has entered into a clinical trial collaboration and supply agreement with Merck (known as MSD outside of the United States and Canada). FX-909, a first-in-class orally available small molecule inhibitor of PPARG, the master regulator of the luminal lineage, will be evaluated in combination with KEYTRUDA® (pembrolizumab), Merck’s anti-PD-1 (programmed cell death receptor-1) therapy, in a new cohort within the company’s ongoing Phase 1 study in locally-advanced or metastatic urothelial cancer (UC).
“FX-909 has achieved clinical proof of concept in the Phase 1A trial as a monotherapy, and we are very pleased to announce this agreement with Merck to add a combination arm to our ongoing Phase 1 study,” said Michaela Bowden, PhD, Chief Development Officer. “FX-909 directly targets luminal cancer cells along with driving immune modulation, inducing pro-inflammatory signaling and T-cell expansion in circulation. Combining FX-909 with an anti-PD-1 may provide a one-two punch to overcome IO resistance, opening the door to first-line treatment for advanced UC, earlier stages of disease, and other solid tumors in which PPARG actively drives immune evasion.”
Under the terms of the supply agreement, Merck will provide its anti-PD-1 therapy KEYTRUDA to be used in combination with FX-909. The Phase 1 study combination cohort is expected to begin enrollment in the first quarter of 2026 and will investigate the safety, tolerability, immunologic effects and preliminary efficacy of escalating doses of FX-909 in combination with standard dose pembrolizumab in patients with advanced urothelial carcinoma.
About Flare Therapeutics Inc.
Flare Therapeutics is a clinical-stage biotechnology company exclusively focused on drugging transcription factors to fully unlock the therapeutic potential of this previously elusive target class. The company’s lead program, FX-909, is a first-in-class orally available small molecule inhibitor of PPARG, the master regulator of the luminal lineage, that is initially being developed for locally advanced or metastatic urothelial cancer. FX-909 has achieved clinical proof-of-concept in a Phase 1A study as a monotherapy and is actively dosing patients in a Phase 1B expansion study to determine the recommended Phase 2 dose in a biomarker-defined population. The second lead program, FX-111, is a novel and highly differentiated potent and selective degrader for ARON, the transcriptionally active, hormone-bound androgen receptor. This approach offers the potential to overcome key vulnerabilities of conventional therapies that target AROFF and has broad potential across prostate cancer at all stages. FX-111 is undergoing Investigational New Drug (IND)-enabling studies for initial development for the treatment of metastatic castration-resistant prostate cancer (mCRPC). These two programs, along with an earlier-stage portfolio targeting transcription factors involved in oncology and other therapeutic areas, leverage Flare Therapeutics’ integrated discovery platform of capabilities that identifies novel validated ligands to the undrugged proteome. For more information, please visit www.flaretx.com and follow us on LinkedIn.
KEYTRUDA® is a registered trademark of Merck Sharp & Dohme LLC, a subsidiary of Merck & Co., Inc., Rahway, NJ, USA.
Contacts:
Investors:
Sarah McCabe
investorrelations@flaretx.com
Media:
Timothy Cockroft
media@flaretx.com
