QLT Inc and Novartis Ophthalmics, the eye health unit of Novartis has started the patient enrollment in two phase III clinical trials using photodynamic therapy (PDT) with verteporfin for the treatment of multiple basal cell carcinoma.

The trials are designed to determine the safety and efficacy of using verteporfin with PDT to eliminate multiple basal cell carcinoma. Approximately 180 patients will be enrolled in two randomized, multi-centered, placebo- controlled trials at 19 centers in North America.

The design of the phase III program is based on the results of a randomized phase II clinical study conducted at four centers with 421 tumors treated in 54 patients. The phase II trial demonstrated the preliminary safety and efficacy of verteporfin at three different light doses in patients with non-melanoma skin cancer with multiple lesions. The group of patients exposed to the highest light dose had the best response rate with 98% of the assessed tumors showing a complete clinical response six months after initial treatment.

"Photodynamic therapy using verteporfin has a high probability of success and offers clear advantages over existing treatments because it is a non- invasive procedure that can treat multiple tumors simultaneously," said Mohammad Azab, QLT Inc's senior vice president, clinical and medical affairs. "Randomized phase II results showed a 98 per cent clinical response rate with a good cosmetic outcome."

Marketed by Novartis Ophthalmics as Visudyne, verteporfin is the therapy of choice in some forms of wet age-related macular degeneration (AMD), the leading cause of blindness in people over the age of 50. Visudyne has been developed by QLT and Novartis Ophthalmics and is available in more than 60 countries.