Extended follow-up from a Phase 2a trial shows that CAN-2409, an experimental “in situ” tumor vaccine, may significantly improve survival in patients with advanced non–small cell lung cancer (NSCLC) who no longer respond to immune checkpoint inhibitors.
At 24 months, 50% of patients were still alive, an increase from earlier results. Median overall survival reached 25.4 months, more than double the typical 9.8–11.8 months seen with standard chemotherapy like docetaxel. Some patients showed long-term benefit, with 13% surviving beyond 50 months.
CAN-2409 is a modified virus injected directly into tumors. It delivers a gene that makes cancer cells vulnerable to an antiviral drug, valacyclovir. This combination causes cancer cells to die in a way that activates the immune system, helping turn “cold” tumors into “hot” ones that are more responsive to immunotherapy.
The study also found that long-term survivors had stronger immune-related signals, including increased interferon activity and better antigen presentation. The treatment remained safe, with no new side effects seen across more than 1,000 patients. Notably, many responders had low PD-L1 levels, a group that عادة responds less well to immunotherapy.