Vaccine May Boost CAR T-Cell Activity in Solid Tumors
Researchers are testing a new approach using an amphiphilic cancer vaccine to deliver CAR T-cell therapy to solid tumors, and the results of preclinical studies are promising, according to findings published in the journal Science (https://doi.org/10.1126/science.aav8692).
Previous studies have found that a solid tumor’s immunosuppressive environment causes CAR T cells to dysfunction at the tumor site when delivered using current methods. To bypass that mechanism, researchers investigated using an antigen-linked vaccine to bind with albumin in the blood and deliver the therapy directly to the lymph nodes and their dense population of immune cells. Studies in mice have shown enhanced T-cell proliferation with that approach.
The current study’s vaccine-based method resulted in “a CAR T population nearly double the size achieved by administering a 200-fold greater number of CAR Ts without vaccination,” the authors reported. In mouse studies with EGFR-positive tumors, CAR T cells administered without the vaccine produced no effect, but infusing CAR T cells with the amphiphilic vaccine eliminated the tumors in a majority of the mice. The vaccinated mice also rejected future EGFR-positive and EGFR-negative tumor cells injected two months later.