MedPacto adds middle-dose cohort to Phase 2 osteosarcoma trial... U.S. FDA approves amendment
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- 2026-10-19 13:46:11
- Updated
- 2026-10-19 13:46:11
MedPacto said on the 19th that the U.S. Food and Drug Administration (FDA) had approved an amendment to the investigational new drug (IND) application for its Phase 2 osteosarcoma trial of vactosertib. Earlier, in September, the company also received approval for the same amendment from South Korea’s Ministry of Food and Drug Safety.
Under the amendment, a middle-dose cohort receiving 200 mg twice daily will be added to the existing high-dose cohort receiving 300 mg twice daily. The middle dose for adolescent patients is 150 mg twice daily. The trial is being conducted simultaneously in South Korea and the United States.
MedPacto expects the amendment to allow it to evaluate treatment responses more precisely by dose and obtain efficacy data. A company official said, "Since the treatment response in the middle-dose cohort was relatively favorable in Phase 1, we expect approval of this amendment will allow us to validate the optimal dose."
In the earlier Phase 1 trial of vactosertib for osteosarcoma, the objective response rate (ORR), including complete response (CR), was 36.4%. The ORR is the combined proportion of partial responses, in which tumors shrink, and complete responses, in which tumors disappear. MedPacto said this figure was at least three times higher than with existing treatments. The company also said it had obtained data meeting the trial protocol’s essential requirements in the ongoing Phase 2 trial.
Osteosarcoma is a rare malignant tumor that develops in the bones and occurs mainly in children, adolescents and young adults. Because existing treatments have limitations in their effectiveness and in improving survival rates, the need to develop new therapies has been raised.
[email protected] Sanghee Jeong Reporter