Submission of rolling BLA request for OST-HER2 to FDA to begin in Sep 2025

“It is clear from the End of Phase 2 Meeting that FDA is committed to finding paths forward to bring new therapies forward for osteosarcoma given the continued high mortality rates in this rare pediatric cancer,” said Paul Romness, MHP, Chair & CEO of OS Therapies. “We have already begun the work of preparing responses to FDA’s comments stemming from the meeting and look forward to beginning the rolling BLA submission later this quarter. We will continue the highly productive ongoing dialogue we have with FDA as it relates to OST-HER2’s potential to improve both Event Free Survival and Overall Survival in the fully resected, pulmonary metastatic osteosarcoma setting. We expect that the October 10th, 2025 workshop FDA and OSI are holding will provide the opportunity for stakeholders to coalesce around the key outcome measures that are clinically meaningful for the brave patients, their families and clinicians who help manage this difficult to treat patient population.”