Provectus Pharmaceuticals, Inc. announced that a second group of subjects has been treated in the company's phase 1 clinical trial of PV-10 (Provecta) for ablation of metastatic melanoma, an aggressive and often fatal form of skin cancer.

Treatment with PV-10 was well tolerated by all subjects, with no evidence of systemic or serious local side effects. Most subjects have exhibited evidence of efficacy, ranging from tumour shrinkage to complete ablation. Several also exhibited subsequent shrinkage of untreated tumours, a response characteristic of the "bystander effect." These results achieve the primary study endpoints of safety and preliminary efficacy assessment.

Based on these promising results, the company has expanded the scope of the study to include a third group of subjects who will receive treatment of up to 20 melanoma lesions. The maximum lesion diameter will also be doubled and study eligibility expanded to include stage IV subjects (those who have distant metastases). These changes will allow the company to further assess performance of PV-10 and validate anticipated phase 2/3 study design parameters where all accessible lesions are expected to be treated.

"We are enthusiastic to continue our studies with PV-10, and the possibility that the agent has some potential to treat systemic disease is interesting," noted Professor John Thompson, director of the Sydney Melanoma Unit and a principal investigator for the study. "Clearly we need to do more work to fully assess its value in control of metastatic disease," he added.

PV-10 is an agent that is retained in tumour tissue while leaving normal tissue unharmed, thereby killing the tumour and sparing healthy tissue. Pre- clinical animal studies have shown broad-spectrum applicability of the agent for selective ablation of a number of focal cancers, including melanoma, breast carcinoma, and hepatocellular carcinoma.

Provectus is preparing to begin phase 2 clinical studies for the company's topical agent Xantryl, a treatment for psoriasis.