Johns Hopkins researchers say an experimental vaccine aimed at mutant KRAS, which is a common driver of pancreatic cancer, has sparked strong immune responses in people considered at high risk. In a small phase 1 trial of 20 participants with pancreatic cysts or hereditary risk, most developed robust T cell responses and, after a median follow up of about 16.5 months, none had gone on to develop pancreatic cancer.
Trial results and safety
According to Johns Hopkins Medicine, the peptide vaccine, called mKRAS-VAX, generated KRAS-specific T cell responses in 18 of the 20 participants (90%), with a median 18.2 fold increase in those cells. The release notes that vaccine-induced T cell clones were detectable for up to two years and that, after a median of 16.5 months of follow up, none of the participants had developed pancreatic cancer. Reported treatment-related side effects were generally mild to moderate and mostly involved injection site pain, fatigue and flu like symptoms.
Study design and imaging findings
The full phase 1 report, published July 16 in Cancer Discovery, explains that participants received four vaccine doses over 13 weeks between April 2022 and February 2026. An exploratory imaging review found that five small pancreatic cysts completely resolved and three partially regressed, while the remaining cysts stayed stable. The authors emphasized that the trial was designed and sized to evaluate safety and immunogenicity, not to definitively show that the vaccine prevents pancreatic cancer.
Expert caution and next steps
Local coverage also highlighted comments from Dr. Amy Ho, who cautioned that higher T cell counts in the bloodstream do not automatically mean those cells are reaching problematic cells inside the pancreas. As reported by WOAI, Ho noted that the vaccine’s safety profile makes a phase 2 trial realistic, while also pointing out that later stage trials can take many years to complete.
How this fits into broader research
mKRAS-VAX builds on earlier Johns Hopkins work that combined KRAS vaccines with checkpoint inhibitors. A related trial published in Nature Communications reported durable responses and longer disease free intervals. As AACR has noted, advances in vaccine platforms and immune monitoring have made preventive vaccine strategies more workable than they were a decade ago.
Funding and conflicts
Johns Hopkins Medicine discloses that several study authors are founders, consultants or equity holders in Adventris Pharmaceuticals and that the university has reviewed and approved those financial relationships. The disclosure does not alter the reported safety findings, and the authors state that the financial ties are being managed under institutional conflict of interest policies.
Trials, eligibility and how to learn more
The phase 1 study opened under trial number NCT05013216 at Johns Hopkins. The ClinicalTrials.gov entry outlines cohorts for people with hereditary PDAC risk or pancreatic cysts. Patients interested in potential enrollment or surveillance options are advised to discuss eligibility with their clinicians and to review the detailed listing on ClinicalTrials.gov.
Researchers describe these results as an important proof of concept: the vaccine appears to activate KRAS-specific immunity in people at risk, but only larger and longer trials will show whether it truly prevents pancreatic cancer. For now, the early data point to a possible path toward intercepting a disease that remains difficult to detect and treat.
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