Promising Results from a New Vaccine Against Pancreatic Cancer

SadaNews - A US clinical study revealed that a new experimental vaccine targeting genetic mutations associated with pancreatic cancer successfully stimulated a strong and long-lasting immune response in individuals highly prone to the disease.

Researchers from the Kimmel Cancer Center and the Skip Viragh Center for Pancreatic Cancer at Johns Hopkins University explained that the vaccine could pave the way for developing new means of preventing one of the deadliest types of cancer. The results were published on Thursday in the journal "Cancer Discovery."

Pancreatic cancer is one of the most dangerous types of cancer; it arises from abnormal growth of pancreas cells and the formation of malignant tumors. Adenocarcinoma of the pancreatic duct is the most common type, typically developing over years from precancerous lesions or cysts, providing an opportunity for early intervention before a tumor appears.

This type of cancer is linked to genetic changes, most notably mutations in the "KRAS" gene, found in most cases, making it a major target for prevention and early treatment research.

The researchers tested an experimental vaccine known as "mKRAS-VAX," designed to target "KRAS" mutations, with the aim of training the immune system to recognize and eliminate cells carrying these mutations before they turn into cancerous cells.

The clinical trial, which was in phase one, included 20 individuals with a genetic predisposition to pancreatic cancer, along with observed changes in the pancreas detected via medical imaging, which are factors associated with an elevated risk of the disease. The participants received four doses of the vaccine over 13 weeks, with monitoring of immune response and treatment safety.

The results showed that 18 out of 20 participants, or 90 percent, developed a strong immune response; the activity of T cells specialized in recognizing "KRAS" mutations increased by an average of 18.2 times compared to their levels before vaccination.

The vaccine also stimulated two major types of T cells capable of attacking infected cells, in addition to forming long-lasting immune memory cells. Some T cells targeted against "KRAS" mutations remained detectable for up to two years after vaccination.

During a follow-up phase averaging 16.5 months, no pancreatic cancer developed among any of the participants, nor did any high-risk pancreatic lesions appear that necessitated surgical removal.

Exploratory analyses of imaging also revealed promising results; small cysts completely disappeared in 5 participants, while their size partially decreased in 3 others, and remained stable in the rest of the participants.

Regarding safety, the vaccine showed a good level of tolerance; all side effects associated with it were classified as mild to moderate, including injection site reactions, fatigue, chills, and flu-like symptoms, all of which resolved without the need for treatment.

The researchers pointed out that these results do not yet prove that the vaccine definitively prevents pancreatic cancer, as the study was primarily designed to assess its safety and ability to activate the immune response, not to measure its preventive efficacy, in addition to the limited number of participants and the short duration of follow-up.

However, the researchers believe that the results represent preliminary evidence for the potential use of vaccines to train the immune system to eliminate cells carrying mutations associated with cancer before they turn into tumors, which is a new preventive approach that could change the future of combating this disease.