Scientists Dale Boger and Nobel laureate Bruce Beutler, of the University of Texas Southwestern, conducted a study on the efficacy of an oncology vaccine with an adjuvant molecule, Diprovocim.
When scientists added the molecule Diprovocim to the immunotherapy vaccine being tested, mice with aggressive melanoma that received the treatment, alongside a PD-L1 inhibitor, showed a 100% survival rate.
Additionally, researchers noted tumors could not be re-established in the mice that were administered the vaccine.
Dale Boger, one of the lead researchers of the study told us the adjuvant molecule bolsters the anti-PD-L1 treatment.
“PD-L1 put the brakes on the immune system, preventing it from recognizing and removing/killing the aberrant cells of the tumor. Anti-PD-L1 antibodies remove this barrier and allow full expression of immune response,” he explained.
The immunotherapy vaccine draws cancer fighting cells to tumor sites, as well as prohibiting growth and fighting tumor cells if they return. The researchers stated that just as vaccines can train the body to protect from pathogens, an immunotherapy vaccine can also train the body to fight off tumors.
Boger furthered, “The stimulators of the immune response further increase this immune response and can also be used to help train (via vaccination) the immune system to recognize the foreign-like proteins (mutated proteins) found in tumors.”
Further studies showed that Diprovocim additionally boosts the vaccine's power to fight cancer by stimulating the immune system to create tumor-infiltrating leukocyte cells.
In lab studies of mice with aggressive melanoma, eight were given the cancer vaccine, eight received the vaccine with Diprovocim, a PDL-1 inhibitor, and eight received the cancer vaccine with an alternative adjuvant (alum).
The researchers plan to move the vaccine into pre-clinical testing and have acknowledged a financial interest in Tollbridge Therapeutics, which holds a license for the patent of Diprovocim.
Boger told us that Diprovocim is in ongoing preclinical development studies needed for use in human clinical trials. “Tollbridge will be arranging for the funding of these studies and conducting or coordinating these ongoing studies. Potential applications of such a molecule include not only in immune-oncology (oncology vaccinations) but also vaccinations for infectious diseases,” he explained.