The new vaccine may be a potential treatment for pancreatic and colon cancer

A new vaccine is showing encouraging early results as a potential treatment for some patients with pancreatic or colon cancer, according to a study led by researchers at Memorial Sloan Kettering Cancer Center (MSK). The vaccine targets tumors with mutations (or changes) in the KRAS gene, a driving force in many cancers.

This cancer vaccine is different from another type of pancreatic cancer vaccine, which is made specifically for each patient using messenger RNA (mRNA). Both are therapeutic vaccines given after surgery to prevent or delay cancer recurrence in high-risk patients.

“Having an off-the-shelf vaccine would make it easier, faster, and less expensive to treat more patients,” says medical oncologist and pancreatic cancer specialist Eileen O’Reilly, MD, who helped conduct the trial. . and is one of the corresponding authors on the study published in Nature Medicine. “This gives hope to people with pancreatic and colon cancer who have not received effective treatments when their disease returns.”

Dr. O’Reilly is a co-copy author Nature Medicine study, along with Shubham Pant, MD, of MD Anderson Cancer Center, and Christopher M. Haqq, MD, PhD, of Elicio Therapeutics.

Clinical trial results for KRAS vaccine for pancreatic and colon cancer

The phase 1 trial involved 25 patients whose pancreatic or colon cancer had certain KRAS mutations and were at high risk of the cancer coming back after surgery. The results showed that this vaccine is safe and appears to stimulate the patient’s immune system to create cancer-fighting cells:

• 84% of patients had the desired immune response, meaning that immune T cells targeting the KRAS-mutated cancer cells were activated and increased in number.
• Also in 84% of patients, an indicator for prolonged cancer cells -? the amount of tumor DNA circulating in the blood – decreased. In 24% of patients, tumor DNA was completely absent.
• Perhaps most importantly, patients who had a higher T-cell response also experienced longer without the disease coming back, known as relapse-free survival.

In patients whose immune systems appeared to respond to the vaccine, cancer recurrence was delayed compared to patients who did not respond to the vaccine. This is the type of early clinical result that we can rely on.”

Eileen O’Reilly, MD, medical oncologist and pancreatic cancer specialist

How vaccines targeting KRAS mutations differ from personalized mRNA vaccines

A different approach to activating immune system cells was led by surgical oncologist Vinod Balachandran, MD. He is investigating whether a personalized mRNA vaccine using proteins from a patient’s pancreatic tumors will alert his immune system that the cancer cells are foreign. In this way, the mRNA vaccine trains the body to protect itself from cancer cells. This vaccine is now being tested in a phase 2 research study at MSK and other institutions.

Personalized vaccines -? while promising -? they also have challenges. They take time to make and are expensive. In contrast, a vaccine manufactured in batches could be administered to patients with minimal delay and would be cheaper to produce.

“These findings are exciting because they show that we may have more than one way to activate immune cells to target pancreatic cancer,” says Dr. O’Reilly.