OS Therapies Inc. (NYSE: OSTX) is advancing its lead candidate OST-HER2 toward regulatory submissions after reporting strong survival data from its Phase 2b trial. The company announced final 2-year overall survival (OS) data showing a 75% OS rate among 41 patients with recurrent, fully resected, pulmonary metastatic osteosarcoma, compared to 40% in historical controls. Notably, patients who were event-free at 12 months achieved 100% 2-year survival, reinforcing the durable benefit of the therapy.
Building on a successful End-of-Phase 2 interaction with the U.S. Food and Drug Administration (FDA), management is preparing harmonized filings with the UK Medicines and Healthcare products Regulatory Agency (MHRA) and the FDA, with submissions expected around year-end. The company has secured a UK MHRA pre-MAA meeting and a FDA Type C meeting in the fourth quarter of 2025, paving the way for a UK MAA submission and a U.S. Biologics License Application (BLA) filing in January 2026 under Project Orbis. The FDA has aligned on safety, non-clinical, and CMC requirements, while the UK MHRA has accepted the use of historical controls and real-world comparators for a conditional Marketing Authorization Application (MAA). The European Medicines Agency (EMA) has also provided feedback supporting the use of 2-year OS from the Phase 2b trial as the primary efficacy endpoint for conditional approval.
OS Therapies is leveraging its partnership with Eversana for commercialization and anticipates initial Priority Review Voucher (PRV) monetization in 2026, with commercial OST-HER2 revenues beginning in early 2027. The company also announced its intent to spin off OS Animal Health (OSAH) into a separately financed, standalone public company in the first half of 2026, with OSTX shareholders expected to receive direct equity participation in the new listing. OS Animal Health targets a substantial U.S. canine osteosarcoma opportunity.
Financially, OS Therapies reported a net loss of $6.9 million for the third quarter of 2025, compared to $2.9 million in the same period last year, driven by higher regulatory and pre-commercial spending. Cash and equivalents stood at approximately $1.9 million at quarter end, supplemented by post-quarter proceeds from a previously announced ~$7.8 million warrant exercise and inducement exchange, extending the runway into late 2026. During the quarter, the company terminated an Equity Line of Credit (ELOC) and established an at-the-market program, adding financial flexibility as it positions for potential OST-HER2 approval and PRV monetization ahead of the September 30, 2026 sunset date.
Stonegate Capital Partners updated its coverage on OS Therapies, using a probability-adjusted Discounted Cash Flow Model to value the company. The valuation range is $5.59 to $7.58 per share, with a midpoint of $6.44. The model is highly levered to out-year projections due to the long-term nature of the biotechnology industry, indicating potential for significant re-ratings as new data and regulatory milestones are achieved.
