Personalized melanoma vaccine provokes strong immune response
The researchers first sequenced samples of the patients’ tumors and healthy tissue to neoantigens, mutated proteins that are specifically from tumor cells. Using algorithms, the scientists determined which neoantigens would induce the best immune response. In the first clinical trial they administered the personalized vaccines to three patients who were diagnosed with advanced melanoma.
The vaccine appeared to successfully increase the number and variety of T cells, which seek and eliminate cancerous tumors. This increase helps researchers create better cancer immunotherapy options and treatment strategies.
"This proof-of-principle study shows that these custom-designed vaccines can elicit a very strong immune response," Washington University oncologist Gerald Linette said about the trial conducted 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."
The study's co-author and co-director of the McDonnell Genome Institute at Washington University Elaine Mardis said this trial is as personalized as vaccines can get.
"The approach we describe is fundamentally different from conventional mutation discovery, which focuses on identifying mutated genes that drive cancer development," Mardis said. "Instead, we're looking for a unique set of mutated proteins in a patient's tumor that would be most likely to be recognized by the immune system as foreign.”