Pancreatic Cancer Vaccine Still Shows Promise 6 Years Out

A personalized messenger RNA (mRNA) vaccine for pancreatic cancer continues to show promise for improving patient survival, according to 6-year follow-up results of a phase 1 clinical study.

Among the 8 out of 16 patients in the study who initially experienced an immune response to the vaccine, seven (87.5%) were still alive at follow-up, lead investigator Vinod P. Balachandran, MD, reported at the American Association for Cancer Research (AACR) Annual Meeting 2026.

Of the eight patients who did not respond, two (25%) were still alive, with a median survival time of 3.4 years. “This suggests that personalized vaccines can stimulate the immune system in some pancreatic cancer patients, and that these patients continue to do well for several years after vaccination,” said Balachandran, director of the Olayan Center for Cancer Vaccines at Memorial Sloan Kettering Cancer Center in New York City.

The findings suggest that this vaccine has the potential to improve outcomes in patients with pancreatic cancer, which is one of the deadliest cancers, he said.

The 5-year survival rate for pancreatic cancer is currently 13%, according to the American Cancer Society’s Cancer Statistics 2026 report.

Initial results of the trial evaluating the individualized neoantigen vaccine — autogene cevumeran, which is being developed by BioNTech and Genentech — were published in Nature in February 2025.

After pancreatic cancer surgery and chemo-immunotherapy, patients with pancreatic ductal adenocarcinoma (PDAC) received a vaccine personalized to each patient based on unique changes in their tumor DNA.

The eight patients with vaccine-induced T cells had prolonged recurrence-free survival (RFS; median not reached), whereas nonresponders had a median RFS of 13.4 months, the authors had reported in the Nature paper.

This correlation was not confounded by other factors, including those associated with the patient, tumor, treatment, and host immune fitness, Balachandran noted.

In the responders, the T-cell clones had “high magnitude and exceptional longevity,” with an average estimated lifespan of 7.7 years, he said.

A fundamental challenge in developing cancer vaccines has been generating durable functional T cells specific for tumor antigens, and these findings suggest that mRNA-lipoplex vaccines against somatic mutation-derived neoantigens like autogene cevumeran may help overcome this challenge in pancreatic cancer, he and his colleagues concluded in the Nature paper.

The latest findings presented at the AACR annual meeting further underscore the potential of this approach.

At the 6-year follow-up, median RFS was “still not reached” in the vaccine responders vs 1.1 year in the nonresponders, he noted.

“This translates to a difference in overall survival,” he said. “Seven of eight [responders to the vaccine] are still alive 4.5-6 years after surgery.”

And of the 2 of 8 nonresponders still alive, one appears to be mounting a subclinical vaccine-induced T-cell response, he added, noting that this “suggests that inducible vaccine immunity may also impact survival in PDAC.”

“The implication here, we believe, is that even if a cancer has very mutational by-products [like PDAC], these mutational by-products can empower potent and composite immunity,” he said. “This is important because it could potentially expand vaccine eligibility to many cancers.”

Currently, there are about 50 neoantigen vaccine trials in solid tumors ongoing worldwide, he noted.

Memorial Sloan Kettering reports that Genentech and BioNTech are now testing autogene cevumeran in a larger patient population at numerous sites worldwide.

Balachandran reported receiving research support from Genentech, Merck Sharp & Dohme, and AbbVie.

Sharon Worcester, MA, is an award-winning medical journalist based in Birmingham, Alabama, writing for Medscape, MDedge, and other affiliate sites. She currently covers oncology, but she has also written on a variety of other medical specialties and healthcare topics. She can be reached at sworcester@mdedge.com or on X: @SW_MedReporter.

A version of this article first appeared on Medscape.com.