Oral 5-aminolevulinic acid mediated photodynamic diagnosis using fluorescence cystoscopy for non-muscle-invasive bladder cancer: A randomized, double-blind, multicentre phase II/III study

Abstract

Photodynamic diagnosis (PDD) of non-muscle-invasive bladder cancer (NMIBC) following transurethral administration of a hexalated form of 5-aminolevulinic acid (5-ALA), 5-ALA hexyl ester, is widely performed in Western countries. In this study, effectiveness and safety of the oral administration of 5-ALA is assessed in a phase II/III study of PDD for NMIBC in comparison to those of conventional white-light endoscopic diagnosis. Patients with NMIBC were allocated to two groups that were orally administered 10 and 20 mg/kg of 5-ALA under the double-blind condition. Effectiveness was evaluated by setting the primary endpoint to sensitivity. Safety was also analyzed. Moreover, clinically recommended doses of 5-ALA was also investigated as an investigator-initiated multicenter cooperative clinical trial in which five medical institutions participated. All 62 enrolled patients completed the clinical trial. The sensitivities of PDD were higher (84.4 and 75.8% in the 10 and 20 m g/kg-groups, respectively) than those of conventional endoscopic diagnosis (67.5 and 47.6%, respectively) (p = 0.014 and p < 0.001, respectively). Five episodes of serious adverse events developed in four patients; whereas a causal relationship with the investigational agent was ruled out in all episodes. This investigator-initiated clinical trial confirmed the effectiveness and safety of PDD for NMIBC following oral administration of 5-ALA. Both doses of 5-ALA may be clinically applicable; however, the rate of detecting tumors only by PDD was higher in the 20 mg/kg-group suggesting that this dose would be more useful.