Combination of Pexa-Vec, Checkpoint Inhibitors to Be Tested in Advanced Colon Cancer Trial

Combination of Pexa-Vec, Checkpoint Inhibitors to Be Tested in Advanced Colon Cancer Trial

SillaJen and the National Cancer Institute (NCI) are partnering to test Pexa-Vec in combination with specific checkpoint inhibitors for the treatment of patients with advanced stage colorectal cancer (CRC).

The cooperative research and development agreement (CRADA) is expected to facilitate and expedite the development of SillaJen’s Pexa-Vec and promote its future use in the clinics.

Under the agreement, SillaJen will collaborate with Tim Greten, MD, a senior investigator in the Thoracic and Gastrointestinal Oncology Branch of the NCI’s Center for Cancer Research. Greten is an expert in gastrointestinal oncology and tumor immunology.

“Treatment options for advanced colorectal cancer are a significant unmet medical need globally. To date, there has been no approval for checkpoint inhibitor therapy for the vast majority of patients with CRC,” James Burke, MD, chief medical officer of SillaJen, said in a press release.

“Therefore, investigation of the potential for Pexa-Vec to ‘prime’ or sensitize CRC to checkpoint inhibitor therapy is an exciting opportunity to further extend immunotherapy to this substantial number of patients without curative or immunotherapeutic options,” he added. “We believe this trial being conducted in collaboration with Dr. Greten and the NCI will provide an excellent opportunity to assess this potential.”

Pexa-Vec, whose name is derived from pexastimogene devacirepvec, is an oncolytic virus designed to kill cancer cells in three ways. It triggers the breakdown of cancer cells through viral replication. It promotes disruption of blood vessels, reducing a tumor’s blood supply. And the GM-CSF gene it contains attracts immune cells to tumors, stimulating strong anti-tumor responses.

The vaccine’s mechanism of action and safety make it an appropriate candidate for combination treatments. It is currently being tested in combination with Sutent (sorafenib) in advanced liver cancer patients in the PHOCUS Phase 3 trial (NCT02562755).

But the company believes that Pexa-Vec may be used to enhance the anti-tumor effects of other immunomodulatory agents, such as PD-L1 and CTLA-4 inhibitors. In the trial, Pexa-Vec’s efficacy will be assessed through tumor biopsies and other patient samples.

Based on the terms of the agreement, Greten will be responsible for recruiting and treating all colorectal cancer patients at the NCI, and NCI will be managing the study.

Pexa-Vec will be supplied by SillaJen while the PD-L1 and CTLA-4 antibodies will be provided by a third party under a separate researcher and development agreement.

“We welcome the opportunity to collaborate with Dr. Greten in the development of this promising combination therapy,” said Eun Sang Moon, CEO of SillaJen, based in South Korea.

For more information about the early-phase clinical trial in advanced colorectal cancer, interested people can call the NCI’s toll-free number at 1-800-422-6237.