Scientists at the Scripps Research Institute in the United States have proven the effectiveness of a new vaccine against melanoma in experiments on mice. In the drug designed to fight tumors, diprovocim was added, which is an adjuvant, that is, a substance that stimulates immunity. The test results are published in the journal Proceedings of the National Academy of Sciences.
Researchers have tested about 100,000 chemical compounds that could increase the effectiveness of chemotherapy in the fight against melanoma - skin cancer. This made it possible to find a substance called diprovozyme, which binds to toll-like receptors - proteins that activate the cellular immune response.
In the experiment, the scientists used a mouse model of aggressive melanoma. Cancers have been genetically modified to synthesize the egg protein ovalbumin, which acts as an antigen that elicits an immune response. The animals were divided into three groups according to different types of therapy. Some received injections of ovalbumin and anti-PD-L1, a drug that prevents cancer cells from resisting the body's defense systems. In the second group, the rodents were injected with ovalbumin, anti-PD-L1 and diprovocim. In the third group, diprovocim was replaced by another type of adjuvant - alum.
Each mouse received two doses of the drug, with a week between injections. Within 54 days, the mice from the second group demonstrated 100% survival, the rodents from the third group - 25%, and in the first, all died. Moreover, the scientists failed to re-initiate the growth of melanoma in animals that received diprovozyme.
Successful trials in mice do not mean that the new adjuvant vaccine will be as effective in humans. Future tests will have to prove this.