PV-10 therapy reviewed

This article reviewed the available literature on the development, use and potential benefit of PV-10 in the treatment of spreading melanoma.

Spreading, or in-transit, melanoma often presents with lesions along the course of the migrating cancerous cells. The management of in-transit melanoma is challenging, since disease extent and treatments vary greatly. Intra-lesion drug injections have been the focus of recent research, with small clinical trials showing impressive response rates to treatment.

PV-10, also known as 10% rose bengal, is currently being investigated as a potential intralesional melanoma treatment. Rose bengal dye is commonly used as a diagnostic aid in many fields of medicine. A new formulation of rose bengal, PV-10, has been developed to induce chemical destruction when injected into tumor lesions. Preclinical studies with melanoma cells were concluded with promising results, leading to early phase clinical trials in patients with spreading melanoma lesions accessible for direct intralesional injections.

A phase I trial demonstrated that PV-10 intralesional injections are well tolerated, with an excellent safety profile, and result in good response rates. Out of the 25 lesions treated with PV-10, 48% showed good response to treatment, with 36% of lesions showing complete remission. In addition, 28% of the treated lesions achieved stable disease, showing no progression. In the same patients, 26 lesions were left untreated, and observed for bystander response to treatment. An unexpectedly prolonged delay in disease progression was observed in these lesions, with 15% showing complete response and 31% achieving stable disease. These observations suggested a wide spread immune response elicited by local PV-10 treatment. No serious adverse events were noted in response to treatment. A recent phase II trial reported very similar results despite increased drug dosages.

This review concluded that PV-10 is a safe and effective prospect in the treatment of in-transit melanoma. Further large scale trails and research into the combination of PV-10 with other intralesional immunotherapies is warranted.