A long-term follow-up study of an individualized mRNA neoantigen vaccine for pancreatic cancer shows sustained immune activity and strong links to improved survival after surgery. Patients whose immune systems responded to the vaccine had not yet reached median recurrence-free survival after more than three years, while non-responders relapsed in about 13.4 months. The results suggest that the strength of the immune response is a key factor in preventing cancer recurrence.
The study also found that the vaccine generates long-lasting cancer-fighting T cells. Some of these immune cell clones persisted for years, with estimates suggesting that a portion could survive for decades. A booster dose significantly extended their lifespan, creating a durable immune “memory” that continues to monitor for returning cancer cells.
Over time, these T cells evolved into a stable memory-like state rather than becoming exhausted, allowing them to remain active and ready to attack. Researchers also observed that the vaccine could help eliminate cancer cells carrying specific mutations, even in pancreatic cancer, which is typically difficult for the immune system to target.