Flare Therapeutics Presents New Translational Data in Support of Lead Asset FX-909 for the Treatment of Muscle-Invasive Urothelial Cancer at SITC 2023 Annual Meeting

Cambridge, MA – November 3, 2023 – Flare Therapeutics Inc., a clinical-stage biotechnology company targeting transcription factors to discover precision medicines for cancer and other diseases, today revealed molecular real-world data (RWD) demonstrating that high PPARG expression in patients with MIUC is associated with an immunosuppressive tumor microenvironment (TME) and shorter real-world progression-free survival to anti-PD1 treatment. The translational data were shared at the Society for Immunotherapy of Cancer’s 38th Annual Meeting (SITC) 2023 taking place November 1-5, 2023 in San Diego, California.

“While immunotherapy approvals have changed the treatment landscape for MIUC, approximately 70% of patients will still succumb to refractory or acquired resistance,” said Michaela Bowden, Ph.D., Chief Development Officer at Flare Therapeutics. “These results offer a unique opportunity to further investigate an immune-mediated mechanism of action for FX-909 with the potential to combine with an anti-PD1 agent.”In the poster presentation titled, “PPARG amplification is associated with lack of response to anti-PD1 in Muscle-Invasive Urothelial Cancer,”

Molecular RWD, comprising 1,393 genomic and/or transcriptomic profiles from MIUC patients were utilized to evaluate baseline PPARG expression and amplification associated with anti-PD1 response in MIUC patients. Additional key takeaways are as follows:

  • Higher PPARG expression and PPARG amplification are negatively correlated with PD-L1 expression in MIUC.
  • Tumors with elevated PPARG levels and PPARG amplification exhibited a suppressive immune phenotype, typified by an inverse association with CD8+ T cell infiltration.
  • PPARG amplification is significantly associated with shorter real-world Progression Free Survival to anti-PD1.

FX-909, a first-in-class covalent PPARG inhibitor, entered the clinic this year and is currently being evaluated in a Phase 1 study. The data presented today suggest that FX-909 in combination with ICI agents could potentially provide a new therapeutic strategy that helps MIUC patients with high PPARG expression overcome resistance to immunotherapy.

About FX-909

Flare Therapeutics’ lead investigational compound, FX-909, is a first-in-class novel, highly potent and selective small molecule that inhibits the transcription factor peroxisome proliferator-activated receptor gamma (PPARG) to treat patients with the luminal subtype of advanced urothelial carcinoma (UC) and potentially other solid tumors. Preclinical data for FX-909 has demonstrated robust anti-tumor activity, excellent PK/PD correlation, durable efficacy, and a favorable safety profile in mouse models of UC (PPARG-amp and RXRA-mut) at very low oral doses.

About the FX-909 Phase 1 Study

The ongoing phase 1 study is a first-in-human, dose-escalation and -expansion study of FX-909 in patients with advanced solid malignancies, including advanced urothelial carcinoma. The study will evaluate the safety, tolerability, pharmacokinetics, pharmacodynamics and clinical activity of FX-909. FX-909 will be given initially in a dose-escalation phase (Part A) to determine the recommended phase 2 dose. FX-909 will be given initially orally once daily in 28-day cycles. Part B will be a monotherapy expansion phase to further evaluate the efficacy, safety, tolerability, pharmacokinetics, and pharmacodynamics of FX-909 in patients with locally advanced (unresectable) or metastatic urothelial carcinoma. Additional information on this clinical trial can be found on www.clinicaltrials.gov (NCT05929235).

About Advanced Urothelial Carcinoma (UC)

In 2020, there were an estimated 725,549 people living with bladder cancer in the United States alone, making it the sixth most common cancer overall, and fourth most common among men (SEER – 2020). Each year, there are more than 83,000 new cases diagnosed among men and women, and about 25% of those cases are classified as muscle-invasive UC (DRG 2020). Advanced UC has high rates of recurrence, where treatment outcomes have remained poor with typical five-year survival rates of 8% in advanced metastatic disease (SEER – 2020). The transcription factor peroxisome proliferator-activated receptor gamma (PPARG) is associated with the luminal lineage subtype reflecting approximately 65% of all advanced UC cases (Robertson, Cell 2017). Recurrent genetic alterations in PPARG are characteristic of this molecular subtype.

About Flare Therapeutics Inc.

Flare Therapeutics is a biotechnology company exclusively focused on drugging transcription factors (TFs) to fully unlock the therapeutic potential of this previously elusive target class. Flare Therapeutics’ integrated discovery engine converges rich genetic, biochemical, and chemical insights to reveal druggable pockets and identify small molecule ligands capable of modulating TFs of high therapeutic potential. Our proteomic and mass spectrometry platform is powered by a proprietary library of electrophilic compounds unique to Flare Therapeutics. The team has rapidly established an emerging pipeline of programs, highlighted by FX-909, a first-in-class investigational orally bioavailable small molecule inhibitor of PPARG, a master regulator of the luminal lineage in advanced Urothelial Cancer that has entered the clinic. For more information, please visit www.flaretx.com and follow us on LinkedIn.


Julie Seidel
Stern Investor Relations


Peg Rusconi
Verge Scientific Communications


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