Stonegate Capital Partners has initiated coverage on OS Therapies Inc. (NYSE: OSTX), highlighting the company's recent clinical, regulatory, and financial progress. OS Therapies is advancing OST-HER2, a listeria-based immunotherapy for recurrent, fully resected, pulmonary metastatic osteosarcoma—a cancer that has not seen a new FDA-approved therapy in over 40 years.
The U.S. Food and Drug Administration (FDA) confirmed that OST-HER2 meets the biological definition of a Regenerative Medicine Advanced Therapy (RMAT) and issued a Biologics License Application (BLA) number, paving the way 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. The company has secured a U.S. commercial partnership with Eversana, positioning for a potential U.S. launch in the first half of 2026.
Beyond OST-HER2, OS Therapies expanded its pipeline by acquiring Ayala’s listeria immunotherapy platform, adding four clinical-stage and eight pre-clinical-stage programs. The company also formed OS Animal Health to explore applications in canine osteosarcoma, supported by positive veterinary trial data.
Regulatory advancements include a productive End of Phase 2 Meeting with the FDA in August 2025, aligning on CMC and non-clinical matters. The company is 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 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, up from $1.6M in 2Q24, reflecting increased R&D and G&A expenses. Cash stood at $2.8M at quarter-end, but recent financing extended 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 potential PRV monetization, to provide multi-year capital runway for 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, based on a discount rate range of 12.50% to 17.50%. The model is highly levered to out years due to the long-term nature of the industry, leading to potential dramatic re-ratings as new information becomes available.
