OncoC4 has dosed the first participant in the Phase II combination study of its ONC-392 and Merck’s anti-PD-1 therapy, Keytruda (pembrolizumab), in platinum-resistant ovarian cancer (PROC) patients.

The participant was dosed at the Women’s Cancer Care Associates in Albany New York.

The multicentre, open-label, randomised Phase II combination study (PRESERVE-004) has been designed for evaluating the safety and efficacy with the combination of ONC-392 and pembrolizumab in PROC patients.

It builds upon the promising data of ONC-392’s mono-therapeutic activity in the previous clinical trial.

Efficacy, which is measured by objective response rate per RECIST1.1, immune related adverse events (irAEs), and the safety measured by treatment related adverse events (TRAEs), will be the Phase II trial’s primary endpoints.

OncoC4 chief medical officer and co-founder Pan Zheng said: “We are pleased to be making progress on our ONC-392 clinical programme with the dosing of our first patient in the PRESERVE-004 trial in the combination arm with KEYTRUDA.

“We are hopeful these results will build on the promising responses we’ve seen with ONC-392 as monotherapy.”

The PRESERVE-004 study is backed by the company along with Merck and GOG Foundation, a non-profit organisation.

The next generation target-preserving anti-CTLA-4 antibody, ONC-392 is said to be the first known acid pH-sensitive anti-CTLA-4 mAb which interacts with CTLA-4 at a pH typical of normal tissues/organs and the tumour microenvironment.

It allows CTLA-4 to recycle and maintain its protective function against autoimmune diseases while improving the anti-tumour activity.

The anti-CTLA-4 antibody has received fast-track-designation as a monotherapy to treat immunotherapy-resistant non-small cell lung cancer (NSCLC), from the US Food and Drug Administration (FDA).