An international phase 3 study in The Lancet Oncology reported that cretostimogene grenadenorepvec, an intravesical oncolytic immunotherapy, may enable some patients with high-risk, BCG-unresponsive non-muscle-invasive bladder cancer to defer or avoid immediate cystectomy. The trial focused on patients whose disease returned or persisted after Bacillus Calmette-Guérin therapy. The headline result centers on whether the treatment can shift outcomes in a setting where standard practice often escalates quickly to surgery due to limited alternatives. The study is positioned as a potential step-change for a subgroup that generally faces poor durability with current intravesical options. Full details on endpoints and effect sizes were not included in the prompt excerpt, but the report underscores the regulatory and clinical significance of an approach designed to activate tumor-local immune responses directly in the bladder.