Stonegate Capital Partners has initiated coverage on OS Therapies Inc. (NYSE: OSTX), a clinical-stage biotechnology company focused on developing immunotherapies for osteosarcoma and other cancers. The coverage comes as OS Therapies advances its lead candidate, OST-HER2, through clinical and regulatory milestones, with potential for a U.S. launch in the first half of 2026.
OST-HER2, built on a listeria-based immunotherapy platform, has demonstrated statistically significant improvement in 12-month Event Free Survival (EFS) from a Phase 2b trial, supported by interim 2-year Overall Survival (OS) data. The therapy targets recurrent, fully resected, pulmonary metastatic osteosarcoma, an area with no new FDA-approved therapies in over 40 years. Notably, the FDA has confirmed that OST-HER2 meets the biological definition of a Regenerative Medicine Advanced Therapy (RMAT) and has issued a Biologics License Application (BLA) number, preparing for an Accelerated Approval submission. The company is on track to begin rolling BLA submissions in September 2025.
Beyond OST-HER2, OS Therapies has 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. Internationally, OS Therapies has submitted an ILAP to the UK MHRA and scheduled an EMA rapporteur meeting in October 2025, with agencies signaling intent to synchronize reviews via Project Orbis. If approved before September 30, 2026, OST-HER2’s rare pediatric disease designation could qualify for a Priority Review Voucher (PRV), potentially monetizable at ~$155–160 million based on recent transactions.
Financially, OS Therapies reported a net loss of $4.5 million for 2Q25, up from $1.6 million in 2Q24, driven by increased R&D and G&A expenses. Cash stood at $2.8 million at quarter-end, but recent financing—including a $4.2 million warrant exchange in July 2025 and $3.7 million in September 2025—has extended the runway into 2027. Management expects the strengthened balance sheet, combined with potential PRV monetization, to provide multi-year capital to support commercialization. A U.S. commercial partnership with Eversana has been secured to aid in launch preparation.
Stonegate’s valuation, using a probability-adjusted Discounted Cash Flow Model, returns a 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-year projections due to the long-term nature of the industry, leaving potential for dramatic re-ratings as new information emerges. Stonegate Capital Partners is a leading capital markets advisory firm providing investor relations, equity research, and institutional investor outreach services for public companies.
