Second generation photodynamic agents: a review.

Over the last decade, laser treatment of neoplastic diseases has become routine. The ability of these light-induced therapies to effect positive results is increased with the utilization of photosensitizing dyes. The approval of Photofrin in Canada as a first generation photodynamic therapeutic agent for the treatment of some forms of bladder cancer is being followed by the development of other agents with improved properties. At this time a number of second generation photosensitizing dyes are under study in phase I/II clinical trials. A review of the status of these trials along with mechanistic aspects is reviewed in this article. In addition, a review of the status of lasers to be utilized for photodynamic therapy gives some indication of which instruments could be considered for this therapy in the future.