Eric A. Wachter

Chemoablation of metastatic melanoma using intralesional Rose Bengal.

To study the effects of intralesional Rose Bengal for chemoablation of metastatic melanoma. Twenty-six target lesions in 11 patients with locoregionally recurrent disease were injected with the agent PV-10 (10% w/v Rose Bengal in saline) at a dose of 0.5u2009ml/cc lesion volume. An additional 28 untreated lesions were observed for potential bystander effect. The treatment was well tolerated and an objective response was observed in 12 target lesions, with an additional seven lesions remaining static over at least 12 weeks of observation. In this dose-evaluation study, response rate was dose dependent, increasing to 69% after higher dose injections. Nontarget lesions exhibited a 27% objective response rate that increased to 44% in patients exhibiting a positive response of target lesions. These findings indicate that intralesional Rose Bengal is nontoxic and could benefit patients with metastatic melanoma.

Phase 2 Study of Intralesional PV-10 in Refractory Metastatic Melanoma

PurposeThis international, multicenter, single-arm trial assessed efficacy and safety of intralesional rose bengal (PV-10) in 80 patients with refractory cutaneous or subcutaneous metastatic melanoma.MethodsSixty-two stage III and 18 stage IV melanoma patients with disease refractory to a median of six prior interventions 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 52xa0weeks. Objectives were to determine best overall response rate in injected target lesions and uninjected bystander lesions, assess durability of response, and characterize adverse events.ResultsFor target lesions, the best overall response rate was 51xa0%, and the complete response rate was 26xa0%. Median time to response was 1.9xa0months, and median duration of response was 4.0xa0months, with 8xa0% of patients having no evidence of disease after 52xa0weeks. Response was dependent on untreated disease burden, with complete response achieved in 50xa0% of patients receiving PV-10 to all of their disease. Response of target lesions correlated with bystander lesion regression and the occurrence of locoregional blistering. Adverse events were predominantly mild to moderate and locoregional to the treatment site, with no treatment-associated grade 4 or 5 adverse events.ConclusionsIntralesional PV-10 yielded durable local control with high rates of complete response. Toxicity was confined predominantly to the injection site. Cutaneous bystander tumor regression is consistent with an immunologic response secondary to ablation. This intralesional approach for local disease control could be complementary to current and investigational treatments for melanoma.