KRAS-targeting vaccine prompts immune activity in pancreatic cancer trial
A randomized phase 2 trial led by Mayo Clinic researchers found that an investigational vaccine generated immune responses against mutated KRAS in nearly every evaluated pancreatic cancer patient. In an exploratory analysis, patients with stronger immune responses tended to have longer disease-free survival. The vaccine targets seven common KRAS mutations and is designed to reach lymph nodes, where it helps T cells recognize cancer cells with those mutations.
The trial enrolled 144 people whose stage 1–3 pancreatic tumors carried KRAS mutations; all had completed surgery and chemotherapy and showed no visible disease on imaging. Participants were randomized to the vaccine (96) or observation (48). The vaccine is off-the-shelf, covers seven common KRAS mutations, and is intended to reach lymph nodes to help T cells recognize mutant cancer cells.
Although the overall trial did not show a statistically significant improvement in time without cancer returning (23.8 vs. 21.2 months), 89 of 90 evaluable vaccinated patients mounted stronger T-cell responses. An exploratory link suggested that patients with larger responses stayed cancer-free longer, including those with more than ninefold increases.
For pancreatic cancer patients and families, a vaccine that reliably triggers KRAS-directed immunity could eventually add a new option after surgery and chemotherapy, though the trial’s main endpoint was not met. Researchers may use the immune-response signal to guide a larger phase 3 study and identify patients most likely to benefit. Broader impact may depend on confirming survival benefits and access in future trials.