OS Therapies forms subsidiary OS Animal Health to commercialize OST-HER2

OS Therapies (OSTX) launched OS Animal Health, a wholly owned subsidiary focused on commercializing OST-HER2 for the treatment of canine osteosarcoma. OST-HER2 is an off-the-shelf immunotherapy candidate that has shown positive clinical data in both human pediatric and canine osteosarcoma. Parent company OS Therapies is advancing towards an FDA Accelerated Approval submission, anticipated in Q3, for the prevention of recurrence in pediatric patients with fully resected, lung-metastatic osteosarcoma. Concurrently, its wholly-owned subsidiary, OS Animal Health, is focused on re-establishing USDA conditional approval for OST-HER2 in canine osteosarcoma, with a targeted submission in the second half of 2025. OS Animal Health will operate independently from the parent company, with separate funding aligned to the needs of the animal health market. OS Therapies estimates OST-HER2’s addressable opportunity in U.S. canine osteosarcoma to be over $150M. OST-HER2 has the potential to significantly improve how this aggressive cancer is treated in dogs, offering a less invasive and more targeted alternative to current options. OST-HER2, being developed by parent company OS Therapies for pediatric osteosarcoma, has received Rare Pediatric Disease Designation for osteosarcoma from the FDA, and if it receives a conditional BLA via Accelerated Review prior to September 30, 2026, it will become eligible to receive a Priority Review Voucher that it intends to immediately sell. The most recent PRV sale, valued at $155M, occurred in May.