On the 11th, Nature Medicine published a phase 1 clinical trial conducted by the research team of the University of California, Los Angeles. The results showed that a non individualized, mass produced, ready to use peptide vaccine called ELI-002 2P was helpful to extend the long-term relapse free survival of some patients with pancreatic cancer or colorectal cancer.

It is known that the recurrence rate of pancreatic cancer and colorectal cancer is high even after surgery and chemotherapy, especially when there are trace cancer cells left in the body. The design of cancer vaccines aims to stimulate immune cell T cells, specifically recognize and kill cancer cells, and personalize targeting of tumor proteins in patients. KRAS gene in pancreatic cancer and colorectal cancer often carries mutations, which plays a key role in cancer growth, so it is an ideal target for cancer vaccines and other immunotherapies. Although inhibitors and T cell therapy can target KRAS mutant proteins, a therapy based on ready to use vaccines may produce long-lasting and protective immune responses. However, traditional vaccines have not been improved and cannot be successfully delivered to lymph nodes, which are the center of immune response.

The team carried out a phase 1 clinical trial of 25 patients (including 20 patients with pancreatic cancer and 5 patients with colorectal cancer). These patients have completed standard treatment, but there are still signs of residual cancer cells in their blood. They received ELI-002 2P vaccine immunotherapy, which targets lymph nodes with KRAS mutant peptides to help the immune system recognize and attack KRAS mutant cancer cells. After an average follow-up period of nearly 20 months, 68% of the subjects showed specific and potent T cell responses to KRAS mutant tumor proteins. Specifically, patients with the strongest T cell response live longer and have a longer cancer free survival than those with weaker T cell response.

Among the pancreatic cancer patients who received the vaccine, the average total survival time was 29 months after vaccination, and the average relapse free survival time was more than 15 months, which exceeded the historical control data. The research team also found in a group of patients that the ELI-002 2P vaccine not only helps the immune system recognize the target KRAS mutant protein, but also recognizes other KRAS mutant proteins unique to each patient's tumor that are not present in the vaccine. This suggests early signs that ELI-002 2P can induce T cell responses targeting individualized tumor antigens in patients.

The team said that ELI-002 2P helps train immune cells to recognize and attack pancreatic cancer and colorectal cancer more effectively. The vaccine is currently undergoing further testing in a phase 2 randomized trial.