Colorectal Cancer Vaccine Proves Safe in Phase I Trial

In earlier preclinical work in mice, Jefferson researchers demonstrated how the design of their vaccine worked. Tumor vaccines have historically been developed against a sort of molecular sign-post for cancer. Because they come from normal cells, cancer cells share nearly all of the same molecules, making it difficult for the immune system to differentiate normal from cancerous. Tumor antigens are molecules that the immune system can recognize as different from normal. In colorectal cancer, one such molecule called GUCY2C, was identified by Scott Waldman, MD, PhD, the Samuel M.V. Hamilton Professor and Director of the Gastrointestinal Cancer Program of the Sidney Kimmel Cancer Center – Jefferson Health. The vaccine developed by first author, Adam Snook, PhD, Assistant Professor in the Department of Pharmacology and Experimental Therapeutics, Dr. Waldman and others, works by activating the immune system against the GUCY2C molecule. By joining the GUCY2C molecule with a molecule that boosts the immune reaction called PADRE, and loading it into an adenovirus vector, the researchers engineered a vaccine that could specifically target the colon cancer. The current clinical trial enrolled 10 patients with stage I or II colon cancer. Patients were given one dose and came back for blood draws 30, 90, 180 days after immunization. Patients experienced some discomfort at the injection site, but reported no serious side effects of the vaccine. The blood samples showed activation of “killer T cells,” the immune cell type the researchers had expected. These killer T cells are responsible for finding and killing colon cancer cells that are responsible for causing the cancer to come back. “We are preparing for a phase II study that will begin recruiting patients this fall,” says Dr. Snook. “We used lessons learned in the first study to modify the vaccine to hopefully make it even more effective.” https://www.technologynetworks.com/cancer-research/news/colorectal-cancer-vaccine-proves-safe-in-phase-i-trial-318665?utm_campaign=NEWSLETTER_TN_Breaking%20Science%20News&utm_source=hs_email&utm_medium=email&utm_content=72115068&_hsenc=p2ANqtz-9TiCn4wM1y4qtkjH6v3BGMDexS5jg9k6jcfX3IFNeVOGY247LVy5kKEukg87km1RF-w-udu7Q7e-maec7BXpPfqqcj5w&_hsmi=72115068