A phase 3 study of cretostimogene grenadenorepvec showed encouraging results in patients with high-risk, BCG-unresponsive non-muscle invasive bladder cancer (NMIBC) with carcinoma in situ (CIS). The treatment produced a complete response in 75.5% of patients at some point during the study.
The responses were long-lasting, with a median duration of at least 27.9 months. More than 64% of patients remained in response after one year, and 60.1% remained in response after two years. Bladder preservation rates were 89% at one year and 81% at two years. In addition, 96.6% of patients did not progress to muscle-invasive bladder cancer during the study period.
The treatment was generally well tolerated. No serious treatment-related side effects, treatment discontinuations, or deaths were reported. The most common side effects were bladder spasms, frequent urination, urgent urination, painful urination, and blood in the urine, with most resolving within one day. The therapy does not require an operating room, anesthesia, or preventive anticholinergic medication. Cretostimogene grenadenorepvec has received FDA Fast Track and Breakthrough Therapy designations and is being evaluated in additional clinical trials for intermediate- and high-risk NMIBC.