Promontory Therapeutics Announces Successful End of Phase 2 Meeting with FDA, Clears Path for Registrational Phase 3 Study

Promontory Therapeutics, a clinical stage pharmaceutical company, recently held a successful End of Phase 2 (EOP2) Meeting with the U.S. Food and Drug Administration (FDA), paving the way for a registrational Phase 3 study of its lead molecule PT-112 in patients with metastatic castration-resistant prostate cancer (mCRPC). The FDA agreed with the proposed dosing regimen, study design, and endpoints, as well as the proposed patient population and proposal for an interim analysis. This allows for the potential pathway for drug approval prior to the full completion of the Phase 3 study.

Key Takeaways:

• The FDA approved the proposed dosing regimen for PT-112 monotherapy in a prospective, randomized controlled Phase 3 registrational study.
• The study design, endpoints, comparator, and statistical framework were agreed upon in principle.
• The proposed patient population within mCRPC and the proposal for an interim analysis were also accepted by the FDA.
• The interim analysis could allow for potential drug approval prior to the full completion of the Phase 3 study.
• Promontory will now prepare its full Phase 3 study submission for final review on the basis of FDA's guidance.
• The company will also conduct similar meetings with international regulatory authorities.
• PT-112 has demonstrated single-agent and combination anti-cancer activity with an attractive tolerability profile in clinical studies.
• The company has conducted research and development programs in the United States, Europe, and Asia.

Statistics:

• 3 randomized dosing arms of PT-112 were used in the proof of concept and dose optimization Phase 2 study.
• Immune response biomarker data were recently presented at the American Association of Cancer Research (AACR) 2025 Annual Meeting.
• Preliminary clinical outcomes of PT-112 monotherapy in metastatic castration-resistant prostate cancer patients will be presented on June 2nd at the American Society of Clinical Oncology (ASCO) 2025 Annual Meeting.

Sources:

• "Promontory Therapeutics Announces Successful End of Phase 2 Meeting with FDA". PRNewswire, May 20, 2025.
• "Promontory Therapeutics Inc. is a privately held, clinical stage drug development company based in New York, focused on small molecules with anti-cancer immune effects".
• "About Promontory Therapeutics" Promontory Therapeutics Inc., accessed May 20, 2025.
• American Association of Cancer Research (AACR). (2025). AACR 2025 Annual Meeting.
• American Society of Clinical Oncology (ASCO). (2025). ASCO 2025 Annual Meeting.