Safety of repeat blue light cystoscopy with hexaminolevulinate (HAL) in the management of bladder cancer: Results from a phase III, comparative, multi-center study

Purpose: The therapeutic benefit of intravesical instillation of hexaminolevulinate (HAL) at the time of transurethral resection of bladder tumor (TURBT) has been demonstrated in multiple studies. The purpose of this study was to prospectively assess the safety of repeated administration of HAL from a phase III pre-trial planned analysis. Materials and methods: All patients evaluated in the study received at least 1 dose of HAL at the time of office cystoscopy, and a subset of these patients (n = 103, 33.2%) received a second dose a few weeks later at the time of TURBT. Adverse events (AEs) were recorded, and the safety of repeat use of HAL was determined by comparing the proportion of patients with AEs considered causally related to HAL in the surveillance examination compared to the OR examination. Association between categorical variables was tested using Fisher's Exact Test, and a P < 0.05 was considered statistically significant. Results: HAL-related AEs were experienced by 6 patients (2.2%) during surveillance cystoscopy and 3 patients (3.4%) following TURBT (P = 0.76); 181 patients (59.5%) had prior exposure to HAL before enrolling in the study with no difference in the number of AEs when comparing prior exposure to HAL to no prior exposure (P = 0.76). Of the patients who previously received intravesical therapy, 8 (2.9%) had at least 1 AE during surveillance compared to 3 (9.7%) who had no prior intravesical therapy (P = 0.09). Conclusions: Repeat use of HAL is safe even when administered within a few weeks of receiving a dose of intravesical therapy.