On June 6, 2025 OS Therapies Inc. (NYSE-A: OSTX) ("OS Therapies" or "the Company"), a clinical-stage cancer immunotherapy and antibody drug conjugate biotechnology company, reported it has submitted a request for Regenerative Medicine Advanced Therapy (RMAT) Designation to U.S. FDA for OST-HER2 in the prevention of metastases in recurrent, fully-resected, lung metastatic pediatric osteosarcoma (Press release, OS Therapies, JUN 6, 2025, View Source [SID1234653768]). RMAT designations are granted to sponsors with regenerative medicine therapies for serious or life-threatening conditions and provide sponsors with various benefits, including eligibility for an accelerated Biologics License Application (BLA) review.
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OST-HER2 has already received Rare Pediatric Disease Designation (RPDD), Orphan Drug Designation (ODD) and Fast Track Designation (FTD) for osteosarcoma from the U.S. FDA. If OST-HER2 receives a conditional BLA via Accelerated Review prior to September 30, 2026, the Company will become eligible to receive a Priority Review Voucher (PRV) that it intends to immediately sell. The most recent publicly disclosed PRV sale, valued at $155 million, occurred in May 2025.
The Company is awaiting feedback by mid-June 2025 from a Type D meeting with FDA regarding the statistical analysis plan to be used in an End of Phase 2 meeting for OST-HER2 in the prevention of metastases in recurrent, fully-resected, lung metastatic pediatric osteosarcoma. Upon receipt of the Type D Meeting feedback, the Company intends to promptly request the End of Phase 2 meeting with FDA in which it will be seek agreement to allow it to begin a rolling BLA submission in the third quarter of 2025. The grant of the RMAT designation in the third quarter of 2025 complements the company’s parallel efforts in other major markets, including Europe and the United Kingdom, where the company plans to seek EMA PRIME Designation and Conditional Market Access (CMA) applications.
In parallel to regulatory engagement and market access planning for OST-HER2, the Company is preparing for the late stage clinical development of other pipeline candidates. As such, the Company is well positioned for sustained growth across multiple therapeutic modalities.