After their advanced kidney tumors were surgically removed, nine patients were protected from the cancer returning thanks to an experimental, personalized cancer vaccine, researchers reported Feb. 5.
The small, phase 1 trial was carried out by the Dana-Farber Cancer Institute, with the results published in Nature on Wednesday. Even more than three years after surgery, none of the patients saw their tumors recur.
The vaccines boosted cancer-targeting T cells 166-fold, the scientists wrote, and these immune cells persisted in the body throughout the study’s duration.
Patients were given the vaccine on days 1, 4, 8, 15 and 22 after surgery, with boosters following at weeks 12 and 20. Five patients also received the checkpoint inhibitor antibody Yervoy (ipilimumab) along with the vaccine.
One patient in the study died from mental health complications that were unrelated to the cancer and treatment, the researchers wrote in their paper. Otherwise, the most common side effects were local reactions to the vaccine injection and flu-like symptoms.
All nine patients had stage 3 or 4 clear-cell renal cell carcinoma, the most common form of kidney cancer. This cancer has a high risk of recurrence, study author Toni Choueiri, M.D., director of Dana-Farber’s Lank Center for Genitourinary Oncology, said in a statement.
The vaccines were made to target tiny, mutant proteins identified from each patient’s surgically removed tumor. The researchers used an algorithm to determine which of these proteins, called neoantigens, would be most likely to fire up an immune response, according to the release.
The personalized neoantigen approach has found success in melanoma, a cancer which has many more mutations that can be targeted. The findings support the idea that the technique can also work in cancers with fewer mutations, such as kidney cancer, according to the release.
“These results support the feasibility of creating a highly immunogenic personalized neoantigen vaccine in a lower mutation burden tumor,” study author Patrick Ott, M.D., Ph.D., director of Dana-Farber’s Center for Cancer Vaccines, said in the release. “Though larger scale studies will be required to fully understand the clinical efficacy of this approach.”
One such larger study is already underway with a similar personalized vaccine in combination with Merck’s Keytruda (pembrolizumab). That randomized phase 2 trial is currently recruiting and seeks to enroll about 272 patients with renal cell carcinoma.
Merck is keen to partner Keytruda with vaccines. The Big Pharma has been collaborating with Moderna on an mRNA-based cancer vaccine that’s currently in a phase 3 trial of high-risk melanoma, while IO Biotech is testing a Keytruda-vaccine combo in squamous cell carcinoma of the head and neck.
Others are also starting to look more closely at neoantigens, with GSK recently inking a research pact with the University of Oxford.