- OS Therapies (OSTX, Financial) receives positive FDA feedback on OST-HER2's accelerated approval pathway for pediatric lung metastatic osteosarcoma.
- The company submits End of Phase 2 Meeting and Breakthrough Therapy Designation requests.
- OST-HER2 is projected to capture a significant share of the $500 million market opportunity in preventing lung metastases.
OS Therapies, Inc. (OSTX), a clinical-stage immunotherapy and Antibody Drug Conjugate (ADC) biopharmaceutical company, has received favorable feedback from the U.S. Food and Drug Administration (FDA) regarding the regulatory pathway for accelerated approval of OST-HER2. The feedback pertains to the company's Phase 2b trial aimed at preventing or delaying recurrence in fully resected, pediatric lung metastatic osteosarcoma.
In concurrence with this development, OS Therapies has initiated requests for an End of Phase 2 Meeting and Breakthrough Therapy Designation with the FDA, highlighting the positive insights from the recent Type D Meeting. The End of Phase 2 Meeting is slated for the third quarter of 2025, aligning with the company's strategic regulatory plans.
Dr. Robert Petit, Chief Medical & Scientific Officer at OS Therapies, expressed satisfaction with the feedback, especially regarding the FDA's acceptance of external control comparators in rare pediatric disease contexts. This guidance will facilitate the company's pursuit of a Biologics Licensing Application (BLA) via the Accelerated Approval Program, enabling potential priority review voucher eligibility upon approval by September 30, 2026.
The market for osteosarcoma treatments was estimated at $1.2 billion in 2022, with a significant portion attributed to addressing pulmonary metastases. OS Therapies forecasts that the OST-HER2 could tap into a $500 million market, given that around 50% of patients develop lung metastasis post-surgical resection and chemotherapy.
OST-HER2 leverages a HER2-bioengineered form of the bacterium Listeria monocytogenes to elicit a robust immune response against HER2-expressing cancer cells, a novel approach showcased in the PBS-streamed movie “Shelter Me: The Cancer Pioneers,” highlighting comparative oncology studies in canines and humans.
For further details, OS Therapies invites stakeholders to attend the presentation of additional data from its Phase 2b trial at the MIB Factor osteosarcoma conference in Salt Lake City on June 28, 2025.
