SillaJen said on Tuesday that it started administering Pexa-Vec, an oncolytic virus therapy, in a phase 1b/2 trial to patients with melanoma in China. The Korean biotech firm is conducting the study jointly with its Chinese partner, Lee’s Pharm.

The phase 1b study in China will be on 46 patients with advanced or metastatic melanoma who have failed first-line treatment until the second quarter of 2022.

The phase 1b study will be an open-label. Lee’s Pharm plans to divide patients into low-dose Pexa-Vec and high-dose Pexa-Vec groups to decide the dose for a phase 2 trial.

Lee’s Pharm plans to evaluate the objective response rate (ORR) and progression-free survival (PFS) of the combination therapy, mixing its PD-L1 drug Socazolimab (code name: ZKAB001) with Pexa-Vec, in patients with advanced melanoma.

Socazolimab is an immune checkpoint inhibitor authorized by the Chinese regulator this year.

Lee’s Pharm licensed in the drug from Sorrento, a U.S. new drug developer.

Lee’s Pharm is testing Socazolimab in various types of cancer, including melanoma, cervical cancer, small-cell lung cancer, and esophageal cancer.

SillaJen also said that a phase 2a trial of Pexa-Vec in kidney cancer was progressing smoothly, as patient enrollment was proceeding in Korea and the U.S.

The company aims to complete the phase 2a study by next year.

“The clinical trial for melanoma has begun in China in earnest. We will make sure we don’t have any glitches,” a SillaJen official said. “We will try our best to promote that Pexa-Vec is the best partner drug for an immune checkpoint inhibitor.”