OS Therapies, Inc. (OSTX) submitted its Phase 2b OST‑HER2 data package to the U.S. Food & Drug Administration on March 31 2026, ahead of a pre‑BLA meeting scheduled for May 2026. The package includes a 75 % two‑year overall survival rate in patients with recurrent pulmonary metastatic osteosarcoma, a key metric that the FDA agreed in December 2025 could serve as a primary endpoint under accelerated approval.
The submission follows the FDA’s December 2025 agreement that overall survival could be used as a primary endpoint and incorporates biomarker analyses that support immune‑biomarker surrogate endpoints. The data package also contains clinical and biomarker information that the FDA has requested for a Type D meeting in March 2026.
OS Therapies is preparing to file a Biologics License Application in January 2026, with the clinical module expected to be submitted by the end of March 2026 after the Type D meeting. A Priority Review Voucher transaction was reported in February 2026 at $205 million, contingent on accelerated approval before September 30 2029.
The company is also targeting conditional marketing authorizations in the U.K. and the European Union later in 2026, with submissions expected by the end of the first quarter of that year.
Despite regulatory progress, OS Therapies remains in a precarious financial position. In the first quarter of 2025 the company reported a net loss of $3.88 million, and the auditor’s report included a going‑concern paragraph. The company’s cash burn and reliance on external financing underscore the need for future capital raises to support its development program.
Management emphasized the significance of the data package. Chief Medical & Scientific Officer Robert Petit stated, “The biomarker and clinical data packages are now with FDA as we begin preparations for our upcoming Pre‑BLA Meeting with FDA.” CEO Paul Romness added, “We believe we are well positioned to bring the first new treatment for osteosarcoma to market in over 40 years.”
The milestone is a key step toward market entry and potential revenue generation, but the company’s financial challenges highlight the importance of securing additional funding and achieving regulatory approval to unlock commercial potential.
The content on EveryTicker is for informational purposes only and should not be construed as financial or investment advice. We are not financial advisors. Consult with a qualified professional before making any investment decisions. Any actions you take based on information from this site are solely at your own risk.