Flare Therapeutics Secures $85M Series C, Appoints Anna Protopapas as CEO to Advance First-in-Class ARON Degrader for Prostate Cancer
核心洞察
Flare Therapeutics (搜索) closed an $85 million insider-led Series C financing led by Third Rock Ventures (搜索) and Nextech Invest (搜索), with participation from Pfizer Ventures (搜索), Eli Lilly, Novartis, and others.
Proceeds will fund advancement of FX-111 (搜索), a first-in-class degrader targeting ARON (搜索), through proof-of-concept clinical studies, with Phase 1A initiation expected in Q3 2026 following FDA IND clearance.
Veteran biotech executive Anna Protopapas, former CEO of Mersana Therapeutics and President of Millennium/Takeda (搜索) Oncology, has been appointed CEO to guide the company's prostate cancer (搜索)-focused strategy.
Flare Therapeutics (搜索) Inc., a clinical-stage biotechnology company focused on drugging transcription factors, announced the closing of an $85 million Series C financing and the appointment of Anna Protopapas as Chief Executive Officer. The insider-led round, co-led by Third Rock Ventures (搜索) and Nextech Invest (搜索), drew participation from a syndicate of prominent life sciences investors including Pfizer Ventures (搜索), Boxer Capital, GordonMD Global Investments LP, Invus, Casdin Capital, Eli Lilly and Company, Novartis, Agent Capital, and Eventide Asset Management.
The financing coincides with a strategic pipeline prioritization that places FX-111 (搜索), a first-in-class degrader targeting the transcriptionally active androgen receptor (ARON (搜索)), at the center of the company's development efforts.
FX-111 (搜索): A Differentiated Approach to Androgen Receptor Degradation
FX-111 (搜索) is designed as a potent and selective degrader of ARON (搜索), the hormone-bound, transcriptionally active form of the androgen receptor. By specifically targeting ARON rather than the inactive AROFF conformation, FX-111 aims to overcome key resistance mechanisms that limit the efficacy of conventional androgen receptor-directed therapies. The company positions this approach as broadly applicable across all stages of AR-driven prostate cancer (搜索), with particular relevance in high-risk disease settings.
The U.S. Food and Drug Administration has cleared the Investigational New Drug (IND) application for FX-111 (搜索), and FlareTx expects to initiate its Phase 1A clinical study in the third quarter of 2026.
"This is an exciting time for Flare Therapeutics (搜索) and for patients with prostate cancer (搜索) who desperately need new options," said Anna Protopapas, incoming Chief Executive Officer. "FX-111 (搜索) offers a new approach to targeting the androgen receptor pathway that has the potential to transform prostate cancer treatment across all stages of disease, while avoiding mechanisms of resistance, representing a genuinely differentiated opportunity."
Beyond FX-111 (搜索), the company is advancing a complementary ARON (搜索) Regulated Induced Proximity Targeting Chimeras (RIPTAC) program through preclinical development, further expanding its ability to address prostate cancer (搜索) across the full disease continuum.
Strategic Reprioritization and FX-909 Partnership Plans
As part of the strategic review, FlareTx will concentrate internal resources on its ARON (搜索) franchise. FX-909, a first-in-class, orally available PPARG (搜索) inhibitor targeting the luminal lineage biology underlying urothelial cancer (搜索), is currently in a Phase 1B dose expansion study. The company intends to advance FX-909 through an external partnership, seeking collaborators to explore combination regimens and earlier lines of therapy where luminal lineage biology plays a defining role.
Investor Conviction in the Transcription Factor Platform
"At Nextech, we focus capital where we see the strongest scientific and clinical conviction," said Kanishka Pothula, Managing Partner at Nextech Invest (搜索). "We believe FlareTx's ARON (搜索)-targeting approach is highly differentiated and has the potential to address important limitations of current prostate cancer (搜索) therapies. This financing reflects our continued conviction in the team, the platform, and the potential of FX-111 (搜索) to become an important therapy for patients with AR-driven prostate cancer."
Abbie Celniker, PhD, FlareTx founder and Partner at Third Rock Ventures (搜索), added: "Our continued support of FlareTx into this next phase of growth is a testament to the differentiated transcription factor platform that has advanced novel programs into the clinic with potentially transformational impact to patients."
Leadership Transition
Anna Protopapas brings extensive oncology leadership experience to the CEO role. She joined the FlareTx board in February 2025 and became Chair in September 2025. Her previous roles include President and CEO of Mersana Therapeutics, where she led the advancement of the company's antibody-drug conjugate platforms and pipeline, and President of Millennium, Takeda (搜索)'s oncology subsidiary. She also served as Executive Vice President of Global Business Development at Takeda. Protopapas currently serves as Chair of the Board at Nuvalent, which was recently announced to be acquired by GSK for $10.6 billion.
Protopapas holds a B.S. in Science and Engineering from Princeton University, an M.S. in Chemical Engineering Practice from the Massachusetts Institute of Technology, and an M.B.A. from Stanford Graduate School of Business.