The results of an international clinical trial evaluating the use of intralesional rose bengal (PV-10), injected in 80 patients with refractory cutaneous or subcutaneous metastatic melanoma were recently reported.
PV-10 is a 10% solution of Rose Bengal, which was originally used as an agent to stain necrotic tissue in the cornea. Its potential use in melanoma was discovered and is being evaluated by Provectus Biopharmaceuticals, Inc. while exploring different formulations for use in photodynamic cancer therapy. The company discovered that PV-10, a formulation developed to be administered directly into solid tumors, destroyed tumors without the need for light activation.
In this study, 62 stage III and 18 stage IV patients with refractory melanoma received intralesional PV-10 into up to 20 cutaneous and subcutaneous lesions up to four times over a 16-week period and were followed for 52 weeks.
The overall response rate to treatment was 51%, and the complete response rate was 26 %. Median time to response was 1.9 months, and median duration of response was 4.0 months, with 8 % of patients having no evidence of disease after 52 weeks. Overall the therapy was well tolerated with no significant treatment-associated side effects reported.
The study authors concluded that intralesional PV-10 yielded durable local control with high rates of complete response. Toxicity was confined predominantly to the injection site and this intralesional approach for local disease control could be complementary to current and investigational treatments for melanoma.
Reference: Thompson JF, Agarwala S, Smithers M, et al. Phase 2 Study of Intralesional PV-10 in Refractory Metastatic Melanoma. Annals of Surgical Oncology, October 2014.