OS Therapies Inc. announced statistically significant positive final 2-year overall survival data from its Phase 2b trial of OST-HER2, an off-the-shelf immunotherapy candidate for the prevention or delay of recurrent, fully-resected, pulmonary metastatic osteosarcoma. The results showed that 75% of OST-HER2 treated patients (27 out of 36 evaluable patients) achieved 2-year overall survival, compared with 40% in historical controls (p < 0.0001). Subgroup analysis indicated that 100% of patients who achieved 12-month Event Free Survival (EFS) reached 2-year overall survival, while 59% of those who did not achieve EFS reached 2-year overall survival. OS Therapies plans to present further data and discuss the regulatory pathway during an investor conference call scheduled for October 13, 2025. Additional prospective biomarker analyses are expected to be completed by November 2025, ahead of planned regulatory submissions in the UK, US, and EU.