OS Therapies (NYSE-A:OSTX) has announced positive data from its Phase 2b clinical trial of OST-HER2, its targeted immunotherapy candidate, in the rare, pediatric-designated indication of preventing recurrent, fully resected, lung metastatic osteosarcoma.
According to OS, the data demonstrate significantly significant results in the study’s primary endpoint: 12-month event-free survival (EFS), where an event is defined as the recurrence of metastatic osteosarcoma. OST-HER2-treated patients showed superior outcomes compared to the leading published historical control group.
“We are extremely pleased with these results of our Phase 2b clinical trial because they show that OST-HER2-treated patients achieved the primary endpoint of 12-month EFS in a statistically significantly higher ratio than comparable historical controls, in addition to increasing the likelihood of 1-year and 2-year survival as compared with comparable historical controls,” Dr. Robert Petit, chief medical and scientific officer of OS, said.
“The strong safety profile shown in this study also supports the use of OST-HER2 in this incredibly difficult-to-treat population that has no currently approved therapies,” Dr. Petit added.
Paul Romness, MHP, chair and CEO of OS, remarked, “The achievement of the primary endpoint in the OST-HER2 phase 2b is a tremendous success that opens the possibility, for the first time, of meaningful therapy for patients suffering from osteosarcoma with lung metastases after resection. This is a leap forward in the development of OST-HER2 and we are pleased that our regulatory strategy is consistent with the FDA’s recent draft guidance update for accelerated approvals. With these positive data in hand, we are preparing to engage with U.S. FDA on an accelerated pathway for approval in this extremely challenging indication. We do not expect to have to treat additional patients as part of this process with FDA.”
