New York, New York — September 30, 2025 — Leads & Copy — OS Therapies Inc. (NYSE American: OSTX) has updated its regulatory filing sequence to prioritize the UK Medicines and Healthcare products Regulatory Agency (MHRA) conditional Marketing Authorisation Application (MAA) final module submission to immediately precede its US FDA Biologics Licensing Application (BLA) final module submission under the Accelerated Approval Program.
The company expects to complete the MHRA conditional MAA submission in December 2025, with the FDA BLA Accelerated Approval submission expected in January 2026. The decision follows positive feedback from the UK MHRA at the August 2025 Scientific Advice Meeting (SAM). The MHRA has accepted the use of historical control data as a comparator arm to support the company’s conditional MAA request and agreed to provide access to the UK’s Clinical Practice Research Datalink (CPRD) to obtain case-matched external control arm data. OS Therapies has also requested an additional Type C meeting with the FDA to review updated overall survival and new biomarker data, aiming to confirm whether immune activation biomarker data can serve as a surrogate marker of efficacy to support Accelerated Approval.
Paul Romness, MHP, Chairman & CEO of OS Therapies, noted the FDA’s agreement on OST-HER2’s strong safety profile and the potential of immune activation biomarker data correlating with canine overall survival, as published in the Journal of Molecular Therapy.
OS Therapies is focused on developing treatments for Osteosarcoma (OS) and other solid tumors. OST-HER2, their lead asset, is an immunotherapy targeting the HER2 protein. It has received designations from the U.S. FDA and European Medicines Agency. The company reported positive data from its Phase 2b clinical trial of OST-HER2 in recurrent, fully resected, lung metastatic osteosarcoma.
In addition, OS Therapies is advancing its next-generation Antibody Drug Conjugate (ADC) and Drug Conjugates (DC), known as tunable ADC (tADC), which features tunable, tailored antibody-linker-payload candidates.
Contact Information:
Investor Relations
Harrison Seidner, PhD
WaterSeid Partners
OSTX@waterseid.com
Public Relations
Jessica Starman, MBA
Elev8 New Media
media@ostherapies.com
