Colorectal and pancreatic cancers (the second and third leading causes of cancer death, respectively) often have mutations in the KRAS protein. Now, a new vaccine targeting KRAS could be used as an off-the-shelf treatment for patients with pancreatic or colorectal cancer, according to a study co-led by researchers at Memorial Sloan Kettering Cancer Center (MSK). The company says it has shown promising initial results.
Some cancer vaccines, such as mRNA-based vaccines, can be customized and custom-made for each patient. Although personalized vaccines are promising, they also have challenges, including cost and long manufacturing times. However, cancer vaccines that can be used as off-the-shelf treatments for specific patients who share specific mutations are an intriguing possibility. Off-the-shelf vaccines can be manufactured in batches and administered to patients with minimal delay. Production costs will also be lower.
“An ‘off-the-shelf’ vaccine would make it easier, faster and cheaper to treat more patients,” said MSK gastrointestinal oncologist Dr. Eileen O’Reilly. Ta. “This gives hope to patients with pancreatic and colorectal cancer who have not received effective treatment even if their disease returns.”
The vaccine being tested here, ELI-002 2P, is a CpG oligonucleotide adjuvant (Amph-CPG-7909).
The authors write in a new paper: was announced on natural medicinesaid the vaccine was safe and elicited significant T-cell responses in patients with KRAS-mutant tumors resistant to immunotherapy.
This paper reports the results of a phase I trial of 25 patients with specific KRAS mutations in pancreatic or colorectal cancer who were at high risk of cancer recurrence after surgery. The results showed that the vaccine is safe and stimulates patients’ immune systems to produce cancer-fighting cells. The authors report that 84% of patients had a favorable immune response. This means that immune T cells targeting KRAS-mutated cancer cells were activated and their number increased. Additionally, 84% of patients had a reduction in the amount of tumor DNA circulating in their blood. Tumor DNA was completely absent in 24% of patients.
Perhaps most importantly, patients with higher T-cell responses also had a longer period of time without their disease returning, known as relapse-free survival.
“In patients whose immune systems appeared to respond to the vaccine, their cancer returned more slowly than in patients who did not respond to the vaccine,” O’Reilly said. “This is the type of early clinical effect we can build upon.”
“These findings are interesting because they show that there may be multiple ways to activate immune cells to target pancreatic cancer,” she added.