New Strategies in Photodynamic Diagnosis of Bladder Cancer

Abstract

Summary Hexyl 5-aminolevulinate hydrochloride (Hexvix®) has been investigated prior to routine clinical use for fluorescence diagnosis of bladder cancer. Preclinical evaluation revealed the drug's safety and tolerability in animals. The feasibility and efficacy of hexyl-5-ALA after intravesical instillation was assessed in 25 patients. There was a preferential PPIX accumulation in neoplastic tissue and after a two hour dwell time the resulting fluorescence intensity was increased at lower concentration as compared to 5-ALA. In a further Phase II multicenter study conducted by Jichlinski et al. 43 out of 45 patients with tumors were diagnosed with the help of hexyl-5-ALA cystoscopy compared to 33 patients with standard cystoscopy which resulted in a sensitivity of 96% compared to 73% under white light. The specificity was found at 80%. Especially 12 out of 13 patients with CIS lesions were diagnosed by hexyl-5-ALA whereas only 4 of these would have been detected under white light cystoscopy. The drug was well tolerated by all patients and did not add any adverse reactions to white light cystoscopy. In June 2002 a Phase III multicenter study with hexyl-5-ALA was initiated by our institution to compare patients management decisions following Hexvix® cystoscopy and standard white light cystoscopy. The study was designed to investigate whether the potentially improved detection of tumors with Hexvix® cystoscopy leads to a different and better treatment of patients with bladder cancer. The study was able to recruit patients rapidly and data management as well as statistics are underway. Study results are expected within the next 6 months.