Medpacto said that it has released the interim results of phase 1b and 2a clinical trials using a combination treatment of Vactosertib and Keytruda (ingredient: pembrolizumab) for treating microsatellite stable (MSS) colorectal cancer.
According to the interim analysis, unveiled during the 2021 American Society of Clinical Oncology (ASCO) conference, the company administered Vactosertib and Keytruda to 50 patients with metastatic MSS colorectal cancer who had failed conventional treatment.
As a result, eight patients showed partial remission (PR), and the objective response rate (ORR) was 16.0 percent. The median overall survival (mOS) was 16.5 months.
Medpacto explained that this data is more meaningful as 64 percent of the patients in this clinical trial are terminally ill patients who have failed three or more previous treatments.
“Also, the results came from a patient group that showed no objective response to Keytruda alone,” the company said. “We expect the combination therapy of Vactosertib and Keytruda will become a new treatment for MSS-type colorectal cancer.”
The company also stressed that its combination therapy shows a better objective response rate than drugs used as standard tertiary treatment.
“Currently, the objective response rate of drugs used as a standard tertiary treatment is less than 5 percent with various side effects,” the company said. “However, the combination therapy showed a dramatic extension for mOS of more than two times compared to the mOS of current standard therapies of 7.1 months or less.”
The results are noteworthy because the combination therapy can become a game-changer in treating MSS colorectal cancer, the company added.
A company official said, “The study was an opportunity to confirm that the Vactosertib combination therapy can create synergistic effects with existing treatments, and to verify its potential as a new treatment alternative.”
It is also meaningful that the results of this study provided the basis for subsequent clinical trials, the official added.