“Harnessing COVID-19 Immunity to Fight Cancer”: Next-Generation Cancer Vaccine ‘PROTEXI’

Celloram has developed a novel dendritic cell vaccine platform that uses existing antiviral immune memory to treat cancer.

Celloram announced on the 28th (local time) that it had published research findings on “PROTEXI,” a novel cancer vaccine platform developed in collaboration with researchers at University Hospitals and Case Western Reserve University, in the international journal Nature Communications. The study presents a new approach that uses immune memory formed through COVID-19 infection or vaccination for cancer treatment.

PROTEXI is a platform for creating dendritic cell vaccines by combining tumor-specific antigens with part of the COVID-19 virus spike protein (an epitope). The vaccine works by stimulating preexisting antiviral immune memory to amplify the immune response against tumors.

According to the researchers, the platform was designed to overcome the limitations of “immune-resistant (immune-cold)” tumors, which respond poorly to existing immunotherapies. It uses existing antiviral CD4+ helper T-cell immunity to strengthen tumor-specific CD8+ cytotoxic T-cell responses and generate sustained anticancer immune memory.

In preclinical animal models of melanoma and breast cancer, PROTEXI slowed tumor growth and improved survival. Efficacy was also confirmed in a humanized mouse model transplanted with immune cells from donors who had received a COVID-19 vaccine.

Seong-jin Kim, MD, PhD, Celloram co-founder and chairman of MedPacto, explained, “PROTEXI is highly innovative because it leverages existing antiviral immune memory, one of the most powerful biological resources already present in the human population. This opens broad possibilities for applications across various cancer types, including combination strategies with existing immunotherapies.”

Based on these findings, Celloram and University Hospitals are preparing the first-in-human clinical trial of PROTEXI in patients with sarcoma. The trial will evaluate the safety, feasibility and immunologic activity of a personalized dendritic cell vaccine approach.