Scientists from Celloram Inc., University Hospitals, and Case Western Reserve University announced on July 27 the development of a new cancer vaccine platform that uses immune memory generated by SARS-CoV-2 infection and vaccination to fight tumors. The study, published in Nature Communications, introduces PROTEXI, a dendritic cell vaccine designed to redirect existing antiviral immune responses toward recognizing and destroying cancer cells.
According to the researchers, PROTEXI pairs tumor-specific antigens with helper signals derived from fragments of the SARS-CoV-2 Spike protein. This approach aims to convert dormant antiviral memory into a catalyst for antitumor immunity. In preclinical models of melanoma and breast cancer, PROTEXI slowed tumor growth, improved survival rates, and enabled recognition of tumors that typically evade the immune system. The vaccine also showed enhanced effectiveness when combined with other immunotherapies and demonstrated results in humanized mouse models using cells from COVID-19-vaccinated donors.
The study found that PROTEXI leverages pre-existing antiviral CD4⁺ helper T-cell immunity to strengthen tumor-specific CD8⁺ cytotoxic T-cell responses and generate durable antitumor memory. "At Celloram, we believe that breakthrough innovation often comes from looking at familiar challenges through an entirely new lens," said Dr. Seunghwan Lim, corresponding author and Vice President of Research and Operations at Celloram Inc. "Building upon these exciting findings, we are actively advancing PROTEXI toward first-in-human clinical evaluation in patients with sarcoma in partnership with University Hospitals," Lim added. "We sought to answer a fundamental question: could the immune system's memory of a viral threat be repurposed to recognize and eliminate cancer more effectively? The preclinical data exceeded our expectations."
Dr. John Letterio, senior corresponding author and Director at University Hospitals Rainbow Babies & Children's Hospital as well as co-Leader at Case Comprehensive Cancer Center, said, "PROTEXI offers a compelling solution by redirecting robust antiviral immune memory toward tumor eradication... These findings have provided the scientific rationale to advance this platform into first-in-human studies for patients with sarcoma."
Dr. Seong-Jin Kim, Co-Founder of Celloram and Chairman of MedPacto Inc., said, "What is particularly elegant about PROTEXI is that it leverages one of the most powerful biological resources already present within the human population: pre-existing antiviral immune memory... The translational potential of this platform is especially exciting because it opens opportunities for broad applicability across multiple cancer types."
Celloram Inc., together with University Hospitals Cleveland Medical Center, plans to begin clinical trials evaluating safety and immunologic activity in sarcoma patients using this personalized dendritic cell vaccine approach.
