Stonegate Capital Partners has initiated coverage on OS Therapies Inc. (NYSE: OSTX), emphasizing the company's recent clinical, regulatory, and financial milestones. OS Therapies is advancing OST-HER2, a listeria-based immunotherapy for recurrent, fully resected, pulmonary metastatic osteosarcoma. The FDA has confirmed that OST-HER2 meets the biological definition of a Regenerative Medicine Advanced Therapy (RMAT) and issued a Biologics License Application (BLA) number in preparation for an Accelerated Approval submission. Final 12-month Event Free Survival (EFS) results from the Phase 2b trial demonstrated statistically significant improvement, supported by interim 2-year Overall Survival (OS) data, further validating the clinical benefit. With a U.S. commercial partnership secured with Eversana, OS Therapies is positioning for a potential U.S. launch in the first half of 2026.
Beyond OST-HER2, the company expanded its portfolio by acquiring Ayala's listeria immunotherapy platform, adding four additional clinical-stage and eight pre-clinical-stage programs. OS Therapies also formed OS Animal Health, a subsidiary to explore applications of OST-HER2 in canine osteosarcoma, supported by positive veterinary trial data. In August 2025, the company held a productive End of Phase 2 Meeting with the FDA, aligning on CMC and non-clinical matters, and confirming no safety concerns with OST-HER2. The company remains on track to begin rolling BLA submissions in September 2025. Internationally, OS Therapies has submitted an ILAP to the UK MHRA and scheduled an EMA rapporteur meeting in October 2025, with the agencies signaling an intent to synchronize reviews via Project Orbis. If approved before September 30, 2026, OST-HER2's rare pediatric disease designation could qualify the company for a Priority Review Voucher (PRV), potentially monetizable at ~$155–160M based on recent transactions.
Financially, OS Therapies reported a net loss of $4.5M for 2Q25, compared to $1.6M in 2Q24, reflecting increased R&D and G&A expenses. Cash stood at $2.8M at quarter-end, with recent financing extending runway into 2027. The company raised $4.2M in July 2025 through a warrant exchange and inducement, completed an additional $3.7M warrant exchange in September 2025, and subsequently terminated its equity line of credit. Management expects this strengthened balance sheet, combined with the potential monetization of a PRV, to provide a multi-year capital runway to support commercialization. Stonegate uses a probability-adjusted Discounted Cash Flow Model, returning a valuation range of $7.09 to $9.94 with a midpoint of $8.29. This announcement is important as it highlights OS Therapies' progress in addressing an area with no new FDA-approved therapies in over 40 years, potentially bringing a new treatment option to patients with osteosarcoma.
