Immune-based therapy elicits remission of metastatic melanoma lesions

Key Points

Bethlehem, Pa. - Clinical trials with a novel immune-based therapy known as PV-10 (Provectus Pharmaceuticals) shows promise in the treatment of advanced melanoma.

Though further confirmation and improvement of the treatment's efficacy is needed in future studies, PV-10 could represent a standard monotherapy or part of a combination treatment in selected patients with advanced metastatic melanoma.

Two studies

In the phase 1 clinical trial completed two years ago, 20 patients with stage III-IV melanoma were treated with a single direct injection of PV-10 into 114 cutaneous and subcutaneous metastatic melanoma lesions. Results showed a selective chemoablation of directly injected lesions and an apparent bystander response in untreated lesions.

Patients tolerated the therapy well, with responses lasting from 12 to 24 weeks. Twenty percent of patients reported a complete remission (CR), and 20 percent had partial remission (PR). In 75 percent of patients, there was a locoregional disease control (SD, stable disease). There was an objective response (OR) in bystander lesions (43 lesions) in 15 percent of patients.

The phase 2 trial was conducted in Australia and the United States and included 80 patients with stage III-IV melanoma. After an initial treatment of PV-10 directly injected into one to 20 cutaneous, subcutaneous or nodular lesions, new or incompletely responsive lesions were treated with a second direct injection at weeks eight, 12 or 16, and were followed up out to 52 weeks. One to two melanoma lesions (including designated visceral lesions) did not receive treatment and were used to assess bystander response. Study endpoints included objective response of injected lesions, objective response of bystander lesions and progression-free survival (PFS) of target lesions.