MedPacto Receives Approval to Amend Vactosertib Osteosarcoma Trial to Determine Optimal Dose

MedPacto has received approval in South Korea to amend its investigational new drug (IND) application for a trial of vactosertib monotherapy in patients with recurrent, refractory or progressive osteosarcoma.

MedPacto said in a disclosure filed with the Data Analysis, Retrieval and Transfer System (DART) on the 15th that the Ministry of Food and Drug Safety (MFDS) approved the trial amendment on the 14th.

The amendment is intended to determine the optimal dose by exploratorily comparing the efficacy and safety of 200 mg BID and 300 mg BID.

The trial is an open-label, multicenter phase 1/2 study evaluating the safety, tolerability, pharmacokinetics and antitumor activity of vactosertib monotherapy in adolescent and adult patients with recurrent, refractory or progressive osteosarcoma.

The trial is being conducted in South Korea and the United States. In South Korea, seven hospitals, including Korea Cancer Center Hospital, are participating. The trial period runs from February 2023 to February 2028.

The target enrollment is 3-18 patients each in the adult and adolescent cohorts in phase 1, and at least 42 patients per dose cohort in phase 2.

The phase 1 primary endpoints are the incidence and characteristics of dose-limiting toxicities (DLTs); the incidence, characteristics and severity of treatment-emergent adverse events (TEAEs); and changes from baseline in physical examinations, vital signs, laboratory tests and electrocardiograms (ECGs).

The phase 2 primary endpoint is the objective response rate (ORR), as assessed by investigators according to the Response Evaluation Criteria in Solid Tumors (RECIST 1.1).

In its disclosure, MedPacto cautioned investors, saying, "Statistically, the probability that an investigational drug will ultimately receive approval as a pharmaceutical product is about 10%."