Stonegate Capital Partners Initiates Coverage on OS Therapies Inc.

Stonegate Capital Partners initiates coverage on OS Therapies Inc. (OSTX), highlighting the company's progress in bringing OST-HER2 to patients with recurrent osteosarcoma. The FDA confirmed OST-HER2 as a Regenerative Medicine Advanced Therapy and issued a Biologics License Application number for an Accelerated Approval submission. The Phase 2b trial showed significant improvements in Event Free Survival and Overall Survival, with an excellent safety profile. OSTX secured a U.S. commercial partnership with Eversana and is positioning for a potential U.S. launch in H1 2026.

Stonegate Capital Partners has initiated coverage on OS Therapies Inc. (OSTX), highlighting the company's significant progress in bringing its lead asset, OST-HER2, to patients with recurrent osteosarcoma. The FDA has confirmed OST-HER2 as a Regenerative Medicine Advanced Therapy (RMAT) and issued a Biologics License Application (BLA) number for an Accelerated Approval submission [1].

The Phase 2b trial of OST-HER2 demonstrated statistically significant improvements in Event Free Survival (EFS) and Overall Survival (OS) with an excellent safety profile. The 12-month EFS showed a p-value of 0.0197, and the interim 2-year OS data had a p-value of 0.0046, indicating strong evidence against the null hypothesis [1].

OSTX has secured a U.S. commercial partnership with Eversana and is positioning for a potential U.S. launch in the first half of 2026. The company's focus on developing the OST-400 natural history database to support a synthetic control arm for its trial is a crucial step in advancing osteosarcoma drug development pathways. The FDA and OS Therapies have also agreed on non-clinical and Chemistry, Manufacturing, and Controls (CMC) matters, and the company is awaiting FDA guidance on efficacy endpoints and statistical analysis plans to support either Accelerated Approval or full marketing authorization [1].

The upcoming FDA/OSI public meeting on October 10, 2025, will focus on advancing osteosarcoma drug development pathways, providing an important forum to establish consensus on clinically meaningful outcome measures for osteosarcoma treatments. OS Therapies has already begun preparations for a rolling BLA submission, expected to start later this quarter, and has received confirmation of eligibility for a PDUFA small business fee waiver, which would reduce regulatory filing costs [1].

References:
[1] https://www.stocktitan.net/news/OSTX/os-therapies-provides-ost-her2-recurrent-fully-resected-pulmonary-na6xbnieyfx7.html