Personalized melanoma vaccines could trigger powerful immune responses against tumor mutations.
These tailor-made vaccines were give to three patients with advanced melanoma, and they proved to boost the number of cancer-fighting T cells responding to the tumors, Washington University School of Medicine reported.
To create these vaccines, a team of researchers sequenced the genomes of patients' tumors as well as healthy protein to pinpoint any mutations that had occurred. They then used a computer algorithm and lab tests to determine which neoantigens were most likely to create an immune response. The vaccines were given to patients whose tumors had been removed, but not before the cancer cells had spread to the lymph nodes. Observations and testing showed the vaccines are most likely effective.
"This proof-of-principle study shows that these custom-designed vaccines can elicit a very strong immune response," said senior author Gerald Linette, a Washington University medical oncologist leading the clinical trial at Siteman Cancer Center and Barnes-Jewish Hospital. "The tumor antigens we inserted into the vaccines provoked a broad response among the immune system's killer T cells responsible for destroying tumors. Our results are preliminary, but we think the vaccines have therapeutic potential based on the breadth and remarkable diversity of the T-cell response."
After the vaccination infusion the patients' blood was drawn every week for about four months, and these samples were then analyzed. The findings showed the vaccine created a diverse army of T cells against neoantigens, suggesting the approach could also be used to activate these types of cells to fight other cancers.
"Our team has developed a new strategy for personalized cancer immunotherapy," Linette said. "Many researchers have hypothesized that it would be possible to use neoantigens to broadly activate the human immune system, but we didn't know that for sure until now. We still have much more work to do, but this is an important first step and opens the door to personalized immune-based cancer treatments."
The findings were published in a recent edition of the journal Science Express.
