Global Regulators Align on OS Therapies Phase 3 OST-HER2 Trial Starting Q3 2026
OSTX•OS Therapies secured alignment with FDA, MHRA, EMA and TGA on OST-HER2 Phase 3 trial design, including a pharmacodynamic biomarker surrogate endpoint. The study will start late Q3 2026 in Australia using Phase 2b drug supply and qualifies for US Accelerated Approval and EU, UK and Australian CMAAs.
1. Global Regulatory Alignment
OS Therapies achieved consensus with the FDA, MHRA, EMA and TGA on the design of its confirmatory OST-HER2 Phase 3 trial in fully resected pulmonary metastatic osteosarcoma, covering CMC plans and the inclusion of a pharmacodynamic biomarker as a surrogate clinical efficacy endpoint.
2. Trial Launch Timeline
The company will initiate the Phase 3 study in late Q3 2026 in Australia under the TGA’s Clinical Trial Notification scheme, leveraging remaining Phase 2b drug product to streamline start-up and minimize manufacturing lead times.
3. Accelerated Approval and CMAA Pathways
Commencement of the trial prior to BLA submission under the US Accelerated Approval Program qualifies OS Therapies for a Priority Review Voucher, while parallel initiation of Conditional Marketing Authorisation Applications in the UK, EU and Australia positions the company for regulatory decisions by year-end.
4. Financial and Market Access Benefits
Alignment on trial design and global regulatory pathways complements the company’s UK R&D tax credit and Australian R&D incentive strategies, and NICE and EU Joint Clinical Assessment processes have been initiated to support early patient access post-approval.
