OS Therapies to Unveil 2.5-Year Survival Data from OST-HER2 Phase 2b Trial at ASCO
OSTX•OS Therapies will present 2.5-year overall survival data from its Phase 2b OST-HER2 trial for resected pulmonary metastatic osteosarcoma at the 2026 ASCO Annual Meeting (May 28–June 2). OST-HER2 holds FDA Orphan Drug, Fast Track and Rare Pediatric Disease designations, with BLA filing slated in H2 2026 and potential Priority Review Voucher eligibility.
1. Upcoming ASCO Trial Data Release
OS Therapies confirms it will present 2.5-year overall survival data from its Phase 2b OST-HER2 trial in fully resected pulmonary metastatic osteosarcoma during the 2026 ASCO Annual Meeting, running May 28 to June 2, 2026.
2. Regulatory Designations and BLA Strategy
OST-HER2 has secured FDA Orphan Drug, Fast Track and Rare Pediatric Disease designations, as well as EMA ODD, FTD and ATMP status. The company plans to file a BLA in H2 2026 under the Accelerated Approval Program, aiming to obtain a Priority Review Voucher for potential sale.
3. Therapy Background and Pipeline
OST-HER2 is a listeria-based immunotherapy targeting multiple HER2 epitopes and has demonstrated clinically significant 12-month event-free and overall survival benefits in Phase 2b. OS Therapies is also developing next-generation tunable ADCs and anticipates Phase 1b OST-504 prostate cancer data in H1 2026.
