OS Therapies Says U.S. FDA Grants Waiver Of Application Fee For BLA Filing Of OST-HER2; Type C Meeting With FDA Scheduled On December 11

• U.S. FDA grants waiver of application fee for BLA Filing of OST-HER2
• Scheduled pre-Marketing Authorisation Application meeting with United Kingdom's Medicines and Healthcare products Regulatory Agency on December 8, 2025
• Scheduled Type C Meeting with United States Food & Drug Administration on December 11, 2025

New York, New York--(Newsfile Corp. - December 5, 2025) - OS Therapies Inc. (NYSE:OSTX) ("OS Therapies" or "the Company"), the world leader in listeria-based cancer immunotherapies, today announced the United States Food & Drug Administration (FDA) granted the Company waiver of the application fee for BLA 125867 for OST-HER2.

Additionally, the European Medicines Agency (EMA) Committee for Medicinal Products for Human Use ('CHMP') granted Union Marketing Authorisation eligibility for OST-HERs in the prevention or delay of recurrent, fully-resected, pulmonary metastatic osteosarcoma (the 'Metastatic Osteosarcoma Program'). EMA CHMP requested an accelerated Marketing Authorisation Application ('MAA') submission for the Metastatic Osteosarcoma Program by February 28, 2026. The intent of the European Union-wide Centralised Procedure is to support the marketing authorization of medicines, where there is a single application, a single evaluation and a single authorization for all EU Member States.

Concurrent with this announcement, the Company has completed pre-meeting submissions to the United Kingdom's Medicines and Healthcare products Regulatory Agency (MHRA) for its pre-MAA meeting on December 8, 2025 and its Type C Meeting with the FDA on December 11, 2025. The Company intends to review final commercial CMC and non-clinical considerations, as well as propose the global confirmatory study design to support an MAA Conditional Approval from MHRA, and a Biologics Licensing Application (BLA) under the Accelerated Approval Program ('Accelerated Approval') from FDA, respectively.