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• Posted May 11, 2023

Vaccine Slows Return of Pancreatic Cancer in Early Trial

A gene-targeted personalized vaccine may delay the return of pancreatic cancer according to a small, but promising, trial.

The mRNA vaccine, which was tailored to the genetic makeup of each patient's tumor, worked in half of those who received it during 18 months of follow-up, researchers reported May 10 in the journal Nature.

Scientists at BioNTech (known for developing a COVID vaccine with Pfizer during the pandemic) and Genentech created the novel vaccine.

Experts reacted to the news with cautious hope.

"It's relatively early days,"Dr. Patrick Ott, of the Dana-Farber Cancer Institute in Boston, told the New York Times.

"This is the first demonstrable success -- and I will call it a success, despite the preliminary nature of the study -- of an mRNA vaccine in pancreatic cancer,"Dr. Anirban Maitra, a specialist in the disease at the University of Texas MD Anderson Cancer Center in Houston, told the Times. "By that standard, it's a milestone."

The idea for the study came together at a meeting of cancer scientists in Mainz, Germany, several years ago. They tested the vaccine in a type of pancreatic cancer that often returns, even in patients whose tumors are removed, the Times reported.

The vaccine worked in about half of the 16 patients, triggering an immune response that may explain why these patients did not relapse during the study period.

In the study, BioNTech scientists used the tumors' genetic data to create personalized vaccines. The goal of the vaccine was to teach the patients' immune systems to attack the tumors.

Patients in the study were still treated with chemotherapy and a medication to keep the immune system on track, so it's possible the vaccine was not the only reason the tumors didn't return, the Times reported.

Patients received their vaccines about nine weeks after their tumors were removed. That is now possible after only six weeks, with the goal of providing future patients with the vaccine in four weeks, BioNTech CEO Dr. Ugur Sahin told the Times.

Still, the vaccine is costly at $100,000 a dose, the Times reported.

"Cost is a major barrier for these types of vaccines to be more broadly utilized,"Dr. Neeha Zaidi, a pancreatic cancer specialist at the Johns Hopkins University School of Medicine in Baltimore, told the Times. Also, the vaccine was not effective in about half of patients, who experienced a relapse after 13 months.

But by creating vaccines that targeted mutated proteins found only on cancer cells, researchers may have realized a breakthrough.

"Just establishing the proof of concept that vaccines in cancer can actually do something after, I don't know, thirty years of failure, is probably not a bad thing,"Dr. Ira Mellman, vice president of cancer immunology at Genentech, told the Times. "We'll start with that."

More information

The American Cancer Society has more on pancreatic cancer.

SOURCE: Nature, May 10, 2023; New York Times