Photodynamic therapy of malignant skin tumors with Benzoporphyrin derivative-monoacid ring A (BPD-MA): preliminary observations

This is a preliminary report of an ongoing clinical trial involving patients with malignant skin tumors. Fifteen patients with malignant skin tumors received an infusion of 0.25 - 0.5 mg/kg of BPD-MA three to four hours prior to irradiation of their tumors with 50 - 150 J/cm2 of 690 nm laser light from an argon pumped tunable dye laser. Tumor response was assessed clinically for up to three months following treatment. In addition, daily serial phototesting of normal skin to filtered light from a xenon arc lamp emitting UVA and visible (UVA/VIS) light was carried out before and after BPD-MA infusion to determine the dose of light required each day to produce `minimal erythema' in normal skin. Complete follow-up data are available for 64 cutaneous tumors in the first fifteen patients treated. A complete clinical tumor response was noted in 63% of the tumors treated, with a partial response (> 50% reduction in tumor area) in 11%. Sensitivity to UVA/VIS light was drug dose-dependent and maximal on the day of treatment. The estimated mean duration of photosensitivity to UVA/VIS light ranged from 2.4 days for the lowest BPD-MA dose (0.25 mg/kg) to 5.4 days for the highest dose (0.5 mg/kg). Cutaneous photosensitivity due to BPD-MA appears to be short-lived. Complete responses for malignant skin tumors have been achieved using BPD-MA doses of 0.25 - 0.5 mg/kg in combination with 50 - 150 J/cm2 of 690 nm laser light.