Early Studies Show Cancer Vaccines Are Promising for Lynch Syndrome, Cervical Lesions
Findings from two recent studies underscore that cancer vaccines may be a larger part of the next wave of novel cancer therapies.
According to data presented at the American Association for Cancer Research 2019 (https://www.aacr.org/Newsroom/Pages/News-Release-Detail.aspx?ItemID=1298) annual meeting, vaccination with as few as four tumor antigens generated antigen-specific responses, reduced intestinal tumors, and improved survival in a mouse model of Lynch syndrome.
To identify the best vaccine targets, researchers narrowed down 13 coding microsatellites that had at least one mutation that occurred in 15% or more of intestinal tumors from Lynch syndrome mice. From there, they found the 10 most promising neoantigens for inducing tumor response, then developed vaccinations for the top 4 neoantigens.
The vaccinations significantly reduced intestinal tumor burden and improved survival in Lynch syndrome mice. In nonvaccinated mice, tumor burden was 61 mg and overall survival was 241 days; in vaccinated mice, tumor burden was 31 mg and overall survival 380 days. Additionally, when combined with naproxen, overall survival increased to 541 days in the vaccinated mice.
Findings from a study published in Gynecologic Oncology (https://doi.org/10.1016/j.ygyno.2019.03.250) showed that a subcutaneously administered therapeutic vaccine eradicated human papillomavirus (HPV)-infected precancerous cervical lesions in 24% of women compared to 10% who received placebo. Clearance rates were two to three times higher with the vaccine despite HPV type or lesion severity.
Researchers randomized the women to receive vaccine or placebo. Both groups received three injections administered at one-week intervals. The women had follow-up evaluations at three and six months and every six months thereafter until month 30.
The authors said that the findings show promise for a nonsurgical treatment option to reduce the risk of HPV-related cervical cancer.