Cancer vaccines aren’t a new concept by any means. The goal for these kinds of jabs is to prime the immune system into better recognizing and killing cancerous cells, helping to eliminate tumors and stave off relapse. The work done during the pandemic has pushed forward the promise of such treatments by adding a new wrinkle to vaccine development: mRNA.
In a new study published Wednesday in Nature, U.S. researchers unveiled a new personalized mRNA vaccine that can be used to combat a particular form of pancreatic cancer called pancreatic ductal adenocarcinoma (PDAC). In a Phase 1 trial, PDAC patients jabbed with the vaccine in combination with chemotherapy and immunotherapy developed a substantial immune response that remained robust even 18 months later.
By 2025, pancreatic cancer is expected to be the second leading cause of death by cancer, second only to lung cancer. Nearly 88 percent of patients die even after chemotherapy and radiation treatment, “highlighting the need for urgent novel treatment,” Memorial Sloan Kettering surgical oncologist Vinod Balachandran, a senior author for the new study, told The Daily Beast.
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The new vaccine’s origins began back in 2017, when a study Balachandran and his colleagues ran focused on unraveling what it was that allowed the 12 percent who did survive to beat pancreatic cancer. That study found that “their bodies are able to mount very strong immune responses to their tumors—spontaneously,” said Balachandran.
And the linchpin specifically seemed to center around the response from T-cells, which help direct how the immune system develops a specific response to pathogens. Moreover, these survivors carried these T-cells well into a decade after their bout with pancreatic cancer, which meant whatever their immune systems were doing was working for the long term as well.
Balachandran and his team began to theorize that these T-cells are recognizing proteins that are manufactured as a result of genetic errors that lead to the rise of PDAC. And so they also began to theorize that priming other immune systems to recognize these proteins could help one’s immune system to rally an effective fight against cancer cells.
Vinod Balachandran.
Karsten Moran for MSKThe problem: these proteins were highly specific to each individual patient. “A vaccine would have to be custom made,” said Balachandran.
The decision was made to make this vaccine using mRNA. Balachandran explained that even before these types of vaccines made their more mainstream debut as COVID vaccines, mRNA was seen as a rapidly scalable material that could present multiple antigens to the immune system at once, including a very strong response from the immune system.
The Phase 1 trial involved administering the new vaccine to 16 PDAC patients who had undergone surgery and were then put on chemotherapy. A robust T-cell response was observed in over 50 percent of patients, and chemotherapy did nothing to derail this response. T-cells were found to remain at elevated levels 18 months later. The team was also very satisfied with the safety of the patients during the trial, and no negative side effects as a result of the vaccine were observed.
Balachandran called the findings “very encouraging… the immune responses you get are high magnitude.”
The vaccine still needs to clear many hurdles before it’s proven to be safe and effective to work, starting with a Phase 2 trial that is supposed to begin very soon. But pancreatic cancer may soon be able to shed its reputation as a death sentence, and survivors may no longer have to live in fear of such high odds of relapse.
