Systemic treatment with the human monoclonal anti-PDL1 antibody durvalumab showed benefit in several cancers. In a phase Ib study published in BJU International, the safety of sub-urothelial durvalumab injection was assessed in patients with non-metastatic muscle-invasive or non-muscle-invasive bladder cancer planned to receive radical cystectomy. Overall, 11 patients received sub-urothelial injection of durvalumab at three pre-determined doses (25, 75 and 150 mg). Mostly grade 1 and grade 2 adverse events (AEs) were reported. The only grade 3 AE observed was not ascribed to durvalumab treatment, and no grade 4 or 5 AEs were reported. A change in tissue immune populations (secondary end point of the study) was observed following durvalumab treatment, with an increase in M2-macrophages (CD163), indicating local immunological response. These results encourage the undertaking of further studies to assess the efficacy of immunotherapy delivered through this local modality, which would avoid AEs associated with systemic treatments.