Experimental Cancer Vaccine Yields Promising Results: NIH Finds Significant Tumor Regression

Scientists found that IV administration of the vaccine boosted the number of cytotoxic T cells capable of infiltrating and attacking tumor cells and engaged the innate immune system by inducing type I interferon.

NIH scientists find that IV administration improves tumor-fighting action.

An experimental therapeutic cancer vaccine induced two distinct and desirable immune system responses that led to significant tumor regression in mice. This is according to a new research study published in the journal Cell, reported by investigators from the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health (NIH).

According to the research findings, intravenous (IV) administration of the vaccine boosted the number of cytotoxic T cells capable of infiltrating and attacking tumor cells and engaged the innate immune system by inducing type I interferon. The innate immune response modified the tumor microenvironment, counteracting suppressive forces that otherwise would tamp down T-cell action. Modification of the tumor microenvironment was not found in mice that received the vaccine via subcutaneous administration (i.e. a needle injection into the skin).

Colorized scanning electron micrograph of a T lymphocyte. Credit: NIAID

Dubbed “vax-innate” by the scientific team, the approach achieves an important goal in the quest for more effective immunotherapeutic vaccines for cancer. The study demonstrates that IV vaccine delivery enables and enhances T-cell immunity by overcoming tumor-induced immunosuppressive activity. According to the researchers, the candidate vaccine might also be given intravenously to people who have already received tumor-specific T cells as a therapy. It also could improve tumor control by increasing the number of T cells and altering the tumor microenvironment to make them function better, the researchers note.

SNAPvax, the name of the experimental vaccine, was designed by Robert Seder, M.D., and colleagues at the NIAID Vaccine Research Center (VRC) together with collaborators from Vaccitech North America, a clinical-stage biopharmaceutical company in Baltimore, Maryland. Vaccitech announced plans to advance the SNAPvax platform for use in treating human papillomavirus (HPV) associated cancer in 2023.

Reference: “Systemic vaccination induces CD8⁺ T cells and remodels the tumor microenvironment” by Faezzah Baharom, Ramiro A. Ramirez-Valdez, Ahad Khalilnezhad, Shabnam Khalilnezhad, Marlon Dillon, Dalton Hermans, Sloane Fussell, Kennedy K.S. Tobin, Charles-Antoine Dutertre, Geoffrey M. Lynn, Sören Müller, Florent Ginhoux, Andrew S. Ishizuka and Robert A. Seder, 26 October 2022, Cell.
DOI: 10.1016/j.cell.2022.10.006