Neoantigen DNA Vaccines Safe, Induce Response in Triple-Negative Breast Cancer

THURSDAY, Nov. 14, 2024 (HealthDay News) — Neoantigen DNA vaccines are safe and capable of inducing neoantigen-specific immune responses in patients with triple-negative breast cancer, according to a study published online Nov. 14 in Genome Medicine.

Xiuli Zhang, M.D., from the Washington University School of Medicine in St. Louis, and colleagues developed a neoantigen DNA vaccine platform capable of presenting human leukocyte antigen class I and II epitopes. Tumor/normal exome sequencing and tumor RNA sequencing were used to identify expressed somatic mutations; cancer neoantigens were identified and prioritized using neoantigen prediction algorithms in order to facilitate vaccine design. The neoadjuvant DNA vaccines were administered in the adjuvant setting in a phase 1 clinical trial involving triple-negative breast cancer patients with persistent disease on surgical pathology following neoadjuvant chemotherapy. Vaccines were monitored for safety and immune responses.

Overall, 18 patients received three doses of a neoantigen DNA vaccine encoding 11 neoantigens on average per patient. The researchers found that the vaccines were well tolerated, with few adverse events reported. Fourteen of the patients had neoantigen-specific T-cell responses. In the cohort of vaccinated patients, recurrence-free survival was 87.5 percent at a median follow-up of 36 months.

“These results support further study of the neoantigen DNA vaccine platform in triple-negative breast cancer and other low mutation burden cancers,” the authors write.

Abstract/Full Text