A promising new vaccine aimed at targeting a common cancer gene mutation could be the breakthrough needed to prevent aggressive pancreatic cancers from returning, according to the results of a small clinical trial. Pancreatic cancer remains one of the most deadly forms of cancer, with a survival rate of just 13% over five years, as reported by the American Cancer Society.

What makes pancreatic cancer even more dangerous is that up to 80% of patients experience a recurrence after initial treatment, according to the National Institutes of Health.

"If you were to ask me what disease most needs something to prevent recurrences, I’d say this one,” said Dr. Zev Wainberg, the co-director of the University of California, Los Angeles’ gastrointestinal oncology program and leader of the clinical trial.

The vaccine, called ELI-002 2P, specifically targets KRAS gene mutations, which are responsible for approximately 25% of all cancers, according to the University of Texas MD Anderson Cancer Center. This mutation is found in nearly 90% of pancreatic cancers and 40% of colon cancers, making it a crucial target for cancer treatment. Historically, KRAS mutations have been nearly impossible to treat with drugs, but recent advances are giving researchers new hope.

The ELI-002 2P vaccine uses peptides—small chains of amino acids—to help train the immune system to recognize and destroy cancer cells carrying the KRAS mutation.

What makes this vaccine particularly groundbreaking is its off-the-shelf design. Unlike many cancer vaccines that need to be tailored for each patient, this one can be used universally without requiring sequencing of the tumor before administration.

The Phase 1 study, published in Nature Medicine on August 12, included 25 participants—20 with pancreatic cancer and five with colon cancer. All participants had previously undergone surgery and chemotherapy for their KRAS-mutated cancers. Despite this, blood tests showed residual disease, or cancer cells too small to detect with imaging scans.

These microscopic cells often lead to cancer recurrence. After surgery, participants were given up to six priming doses of the vaccine, with 13 also receiving booster shots. The entire process lasted six months. The results were promising, with 85% of participants (21 out of 25) showing an immune response to the KRAS mutations.

Two-thirds of these patients had a strong enough immune response to help eliminate lingering cancer cells. Nearly 70% of participants developed immunity to other tumor targets not included in the vaccine. Some participants, dubbed “super-responders,” exhibited exceptionally strong immune reactions and the best outcomes.

For those in the pancreatic cancer group, the vaccine led to an average survival time of 29 months, with patients remaining recurrence-free for more than 15 months post-vaccination—a significant improvement over traditional treatments for resectable cancers. Dr. Wainberg emphasized the success, stating, "That far exceeds the rates with resectable cancers."

Cancer vaccines have been notoriously difficult to develop because cancer cells share many proteins with healthy cells, making it challenging to find safe targets. However, recent advances in mRNA technology and gene sequencing are revolutionizing the development of effective cancer vaccines. The ELI-002 2P vaccine also includes a unique "tail" feature that helps the peptides stay in lymph nodes, where immune cells are activated—an advantage over past peptide vaccines, according to Stephanie Dougan, an associate professor at Dana-Farber Cancer Institute in Boston, who was not involved in the study.

While the results are promising, further research is needed, and a Phase 2 trial is already underway to compare the vaccine's effectiveness with standard care treatments. Dougan called the findings “exciting,” particularly because the long-term survival appeared to be linked to the T-cell response activated by the vaccine. “The idea that you can target KRAS is really exciting,” she said.

As the vaccine progresses through clinical trials, it may offer hope for patients battling pancreatic cancer and potentially other cancers driven by KRAS mutations.