685P - A Multicenter Phase Ii Study of Salvage Photodynamic Therapy Using Talaporfin Sodium and a Diode Laser for Local Failure of Esophageal Cancer After Chemoradiotherapy

Abstract

ABSTRACT Aim: We previously reported that photodynamic therapy (PDT) has a potential to cure local failure after chemoradiotherapy (CRT) for esophageal cancer (EC). However, first-generation PDT using porfimer sodium and an excimer dye laser has several problems: a high occurrence of skin phototoxicity, the requirement of a long light shielding period (6 weeks), and the need for an expensive and large laser generator. Talaporfin sodium (Laserphyrin®) is a second-generation photosensitizer that requires a shorter light shielding period (2 weeks) and induces less phototoxicity. We previously identified the optimum diode laser fluence (100 J/cm2) for PDT using talaporfin sodium in the phase I/IIA study. Therefore, in the present study, we conducted a multicenter phase IIB study to evaluate the efficacy and safety of PDT using talaporfin sodium as a salvage treatment for local failure after CRT or radiotherapy (RT) for EC. (UMI09184). Methods: Eligibility criteria were histologically proven local failure of ≤3 cm in diameter with a clinical depth limited within T2 after definitive CRT or RT (≥50 Gy) for EC. PDT commenced with intravenous administration of 40 mg/m2 of talaporfin sodium, followed by diode laser irradiation with a fluence of 100 J/cm2 and a fluence rate of 150 mW/cm2 4-6 h later. The primary endpoint was the local complete response (L-CR) rate, and the secondary endpoints were confirmed L-CR, local progression-free survival, progression-free survival, local time to treatment failure, and overall survival. The institutional review boards of all institutions approved the study protocol. Results: Between November 2012 and December 2013, a total of 26 patients were enrolled. The clinical depth of the lesions was diagnosed as T1 in 19 patients and T2 in 7 patients by endosonography. PDT using talaporfin sodium was performed in all patients without any serious adverse events. The patients are currently followed up to assess primary and secondary endpoints. Conclusions: The efficacy and safety of second-generation PDT using talaporfin sodium for local failure of EC after CRT will be reported. Disclosure: All authors have declared no conflicts of interest.