A phase II study of lurbinectedin with or without avelumab in small cell carcinoma of the bladder (laser)-design and rationale.

Small cell carcinoma of the bladder is a rare, aggressive malignancy accounting for less than 1% of all bladder malignancies. Treatment regimens are drawn from the small cell lung cancer (SCLC) literature, with platinum and etoposide commonly used in the first-line setting. Unfortunately, responses are generally short-lived, and most patients relapse. There is little evidence to guide selection of later lines of therapy. Lurbinectedin is an alkylating agent with accelerated US FDA approval for use in patients with SCLC. Immune checkpoint inhibitors have also been approved for SCLC, improving survival when added to chemotherapy. This article describes the design and rationale behind LASER, an open-label phase II trial of lurbinectedin with or without avelumab.Clinical trial registration: NCT06228066 (ClinicalTrial.gov).