Turning the Tide Against Pancreatic Cancer with mRNA Vaccines

Vita Sara Blechner, a middle school librarian in Oceanside, New York, experienced a life-altering moment on a Saturday afternoon. She had shooting pains in her back, and after trying an acid reflux pill without relief, her husband suggested they go to the emergency room.

This was March 7, 2020, just days before COVID-19 transformed New York City’s hospitals into chaotic emergency zones. It’s interesting, really; the doctors seemed calm and composed as they performed tests on Blechner, who was 67 at the time. Yet, the results delivered shocking news.

“They said I have a tumor on my pancreas,” she recalled. “And I said, ‘No, it can’t be. This can’t be happening to me. I don’t drink. I don’t smoke. I’m leading a healthy life.’”

After two anxiety-filled days in the hospital, Blechner returned home to evaluate her options. Unfortunately, the choices were limited. Pancreatic cancer is notoriously brutal, with only 1 in 4 patients surviving a year after diagnosis, and 1 in 10 making it to two years.

Heavy with the weight of statistics, Blechner and her family began researching possibilities. They ultimately decided to explore an emerging and sometimes misunderstood area of cancer treatment focused on mRNA technology.

Messenger RNA (mRNA) serves as a messenger that relays genetic information from DNA to guide the production of proteins. Most people might associate it with high school biology or the COVID vaccines. Interestingly enough, long before the pandemic, mRNA was creating waves in cancer research. BioNTech, the company that developed a COVID vaccine for Pfizer, had previously been working on cancer therapies using mRNA for nearly a decade.

The mRNA-based COVID vaccines from Pfizer and Moderna helped to alleviate the impact of the pandemic but also incited political backlash, threatening to stymie advancements in cancer treatments that had been previously gaining momentum. However, after a turbulent year, there are indications that progress is being made again in the field.

“It’s exciting,” remarked Elizabeth Jaffee, deputy director of the Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins University. “There’s been a number of successes in early-stage, positive trials.”

Dr. Catherine Wu, a professor at Dana Farber Cancer Institute and Harvard Medical School, pointed out that recent real-world results prompted the National Cancer Institute to announce a fundraising initiative to gather $200 million specifically for developing novel cancer vaccines.

“We’re getting a lot of support from NCI in terms of developing and promoting cancer vaccines, and mRNA vaccines are a major part of that portfolio,” she shared.

With that in mind, Blechner consulted with experts at Memorial Sloan Kettering Cancer Center, specifically Dr. Vinod Balachandran, who is involved in cancer vaccine research.

Balachandran noted that developing a vaccine for cancer is more complex than creating one for viruses like COVID-19. “Cancer is ourselves. It’s derived from our own tissues,” he explained, highlighting the challenges of making the immune system recognize cancer cells as threats.

Much of his work has centered on pancreatic tumors due to their notorious difficulty to treat. “It’s a cancer where nothing had really worked,” he remarked.

When Blechner reached MSK, Balachandran had just begun a trial for an experimental mRNA-based vaccine targeting pancreatic cancer, combining it with standard immunotherapy and chemotherapy. His ambition? To develop a successful vaccine that could lay the groundwork for treating other types of cancer, potentially unlocking new approaches.

To design the vaccine, he began studying so-called “super-survivors,” the less than 10% of pancreatic cancer patients who live over five years post-diagnosis. Fascinatingly, these individuals’ immune systems were particularly adept at identifying their cancer cells as foreign. Balachandran noted they had about 12 times the T-cells inside their tumors compared to average patients, with these specialized immune cells circulating for over a decade.

Moreover, he recognized these T-cells were not generic warriors but were trained to recognize specific mutations. “To replicate this would require us to teach each individual person’s immune system how to recognize their individual cancer,” he explained. Thus, an individualized vaccine became the goal, utilizing RNA technology for speedy custom solutions.

After Blechner agreed to participate in the trial, she underwent a Whipple procedure to remove her tumor. The tumor was preserved and dispatched to Germany within 72 hours, where technicians at BioNTech prepared a personalized vaccine just for her.

When her vaccine arrived in New York a bit over two months post-diagnosis, she had already started on an immune checkpoint inhibitor designed to enhance her immune response against the cancer. Weekly infusion appointments required her husband, Simon, to drive her into Manhattan amidst the COVID pandemic’s eerie quiet. Rather than running errands, Simon would wait at home on Long Island until it was time to pick her up after her marathon of an eight-hour infusion.

After nine weeks, she was ready to progress to chemotherapy. Unfortunately, the experience was far from smooth. Blechner faced severe side effects that prompted her doctors to halt treatment after just three sessions. “I got very sick,” she remembered.

The ordeal left her hospitalized multiple times, and at one point, she dropped to 90 pounds. “I was constantly nauseous, and my liver was damaged,” she said. Doctors feared they’d never see her again.

Ultimately, by the time she felt well enough to resume treatment, her medical team believed it was too risky. She hoped abandoning chemotherapy wouldn’t impact her overall prognosis, but only time would tell.

Fast forward over six years, and Blechner’s story is one of success. Not only did she surpass expectations by living longer than anticipated, but she also remains healthy—cancer-free.

Of the 16 participants in Balachandran’s trial, eight exhibited a significant immune response to the mRNA vaccine, and seven of those eight are alive and well six years later. The findings were set to be discussed at an American Association for Cancer Research meeting in San Diego.

“It’s exciting,” Balachandran said. He noted, “The implication is that you can generate a strong immune response against the toughest cancers, and it can last for this long. If we could succeed here, it might open doors for many other cancers.”

Nevertheless, while 16 patients may not be statistically definitive, a larger multisite trial has been in progress for about a year.

Additionally, positive news for pancreatic cancer patients continues to emerge. Just recently, former US Senator Ben Sasse revealed in a New York Times interview that he’s been fighting advanced pancreatic cancer with an experimental drug that caused his tumors to shrink, albeit with some agonizing side effects. Moreover, Revolution Medicines reported that its drug nearly doubled survival time for patients with spreading cancer, offering hope for improvements moving forward.

In contrast to the Revolution trial, the MSK study serves as a preliminary validation of the potential mRNA vaccines hold. While the field has generated significant excitement, public backlash over COVID vaccines has tempered enthusiasm, even though most experts regard concerns as unfounded.

In March 2025, another round of challenges presented itself when the acting director of the National Institutes of Health raised alarms regarding mRNA research funding, which led to skepticism among researchers. This skepticism intensified in May when substantial cuts to the National Cancer Institute’s budget were proposed.

Despite this setback, NIH and NCI have announced that they’re now refocusing on innovative areas, including mRNA cancer vaccines, which could pave the way for quicker translational research and more clinical trial opportunities for patients.

Blechner reflects on her experience, telling how “once I hit my fifth year [cancer-free], it really sank in that I’m doing well. I said, ‘I beat the odds.’ Now I’m grateful every day.” She eagerly anticipates milestones like her sons’ weddings and enjoys hosting family events, cherishing every moment.