OS Therapies advanced materially through late-stage regulatory and commercialization preparation as OST-HER2 moved from Phase 2b supported planning toward a more defined global approval pathway in recurrent, fully resected, pulmonary metastatic osteosarcoma. The key change is greater regulatory clarity: EMA initiated rolling review of the OST HER2 Conditional Marketing Authorization dossier, while EMA and Australia’s TGA aligned on 3-year overall survival as the approvable efficacy endpoint. Management also positioned seroconversion biomarker data as supportive surrogate efficacy evidence, shifting the investment debate from early proof-of-concept toward execution across a dense 2026 catalyst calendar. Key milestones include 2.5-year OS data in mid-2Q26, FDA/MHRA meetings in 2Q26, Phase 3 initiation in Australia in 3Q26, 3-year OS data in early 4Q26, and a potential EMA CMA decision in 4Q26.
