An experimental vaccine targeting common gene mutations linked to pancreatic cancer has shown the ability to stimulate long-lasting immune responses in people at high risk of developing the disease, in an early clinical trial that researchers said provides the first evidence in humans that vaccines can be used to intercept before it develops and may protect those at risk of developing pancreatic cancer.
Results from a phase 1 trial, published in the journal Cancer Discovery, indicated that the vaccine was safe and stimulated specialized immune cell responses against mutations in the Kras gene in 90% of participants. Some of these responses remained detectable in the blood for up to two years after vaccination.
The study included 20 people at high risk of developing pancreatic ductal adenocarcinoma, the most common and aggressive type of pancreatic cancer, due to a genetic predisposition and the presence of lesions in the pancreas that appeared in imaging tests, often in the form of small cysts.
The vaccine, known as mKRAS-VAX, targets six of the most common KRAS mutations in pancreatic cancer. It uses protein fragments designed to train the immune system to detect and destroy cells carrying these mutations before they develop into cancerous tumors. The vaccine is administered subcutaneously at weeks one, three, and five, followed by a booster dose at week thirteen.
Disappearance of cancerous cysts
After an average follow-up of 16.5 months, none of the participants developed pancreatic cancer. Researchers also observed that some precancerous cysts shrank or disappeared, but stressed that the trial was small and not designed to prove that the vaccine actually prevents cancer.
