>>23872564
Personalized mRNA Vaccines Will Revolutionize Cancer Treatment—If Funding Cuts Don’t Doom Them
Vaccines based on mRNA can be tailored to target a cancer patient’s unique tumor mutations. But crumbling support for cancer and mRNA vaccine research has endangered this promising therapy
As soon as Barbara Brigham’s cancerous pancreatic tumor was removed from her body in the fall of 2020, the buzz of a pager summoned a researcher to the pathology department in Memorial Sloan Kettering’s main hospital in New York City, one floor below. Brigham, now 79, was recovering there until she felt well enough to go home to Shelter Island, near the eastern tip of Long Island. Her tumor and parts of her pancreas, meanwhile, were sent on an elaborate 24-hour course through the laboratory. Hospital staff assigned the organ sample a number and a unique bar code, then extracted a nickel-size piece of tissue to be frozen at –80 degrees Celsius. They soaked it in formalin to prevent degradation, then set it in a machine that gradually replaced the water in each cell with alcohol.
Next, lab staff pinned the pancreas to a foam block, took high-resolution images with a camera fixed overhead and used a scalpel to remove a series of sections of tumor tissue. These sections were embedded in hot paraffin and cut into slices a fraction of the thickness of a human hair, which were prepped, stained and mounted on glass slides to be photographed again. By the time a pathologist looked at Brigham’s tumor under a microscope the next day, more than 50 people had helped steer it through the lab. Still, this work was all a prelude.
The real action came some two months later, when Brigham returned to the hospital to receive a vaccine tailored to the mutations that differentiated her tumor from the rest of her pancreas. Made of messenger RNA (mRNA) suspended in tiny fat particles, the vaccine was essentially a set of genetic instructions to help Brigham’s immune system go after the mutant proteins unique to her tumor cells. It was, in other words, her very own shot.
It’s been four years since Brigham received the last of nine doses of her personalized vaccine. In that time she’s seen one grandchild finish college and get married and another embark on a Ph.D. She has attended dozens of high school basketball and volleyball games for her third and fourth grandchildren and cradled the family’s newest arrival, a granddaughter born last year. She hosts a weekly mah-jongg-and-dessert gathering for a group of friends on Shelter Island and tries to live out her mother’s maxim of having “a little adventure” each and every day. “I’m a little crippled here and there with arthritis,” Brigham says, but “I never sit still.” And she remains free of pancreatic cancer.
Brigham’s recovery came as part of a small phase 1 clinical trial conducted by Memorial Sloan Kettering in partnership with pharmaceutical companies Genentech and BioNTech—the latter, along with Pfizer, helped to produce the first approved mRNA vaccine for COVID-19. Brigham was one of 16 patients in the study who received the vaccine, administered in tandem with standard drugs, and one of eight who experienced a significant immune response. Six of those eight patients are still in remission, along with one of the eight others who did not show much immune response to the vaccine.
Seven of 16 might not sound like much. But that number suggests that the vaccine has tantalizing potential. Pancreatic cancer can be exceptionally fast-growing, and its first signs—weight loss, cramping, a touch of jaundice—are easily missed, so by the time it is diagnosed it is almost always lethal. Only 8 percent of patients with the most common form of the cancer, ductal adenocarcinoma, survive to the five-year mark, and the vast majority of people with the disease show little response to treatment.
The results of Brigham’s trial were also an early sign that mRNA vaccines may be effective for a wide variety of cancers: whereas pancreatic cancer is known for its low rate of mutations, the earliest data on personalized mRNA vaccines came from studies of melanoma, which researchers had targeted specifically because it tends to mutate so frequently. An earlier phase 2 trial in patients with advanced melanoma found that for those who received both a personalized mRNA vaccine and so-called immune checkpoint inhibitors, the risk of death or recurrence decreased by almost half compared with those who got only checkpoint inhibitors. Ongoing companion trials are targeting kidney and bladder carcinomas and lung cancer. In each case, the vaccine is additive: administered after surgery and with standard drugs. The shot’s job is to prime the immune system to recognize abnormal proteins arising from mutations and attack any lingering malignancy that escaped conventional treatments—or stamp out future recurrence.
1/8