Cretostimogene grenadenorepvec, an intravesical oncolytic immunotherapy, produced complete responses in 75% of patients with high-risk, BCG-unresponsive non–muscle-invasive bladder cancer with carcinoma in situ in the Phase III BOND-003 Cohort C trial. The results, reported in The Lancet Oncology, showed many responses persisted through two years, with mostly mild and transient treatment-related adverse events.