June 5, 2013 | By Márcio Barra
Last week the FDA approved GlaxoSmithKline’s Dabrafenib and Trametinib for metastatic melanoma, alongside a diagnostic test to detect for V600E or V600K mutation in the BRAF gene. Current therapies for metastatic melanoma include surgery, chemotherapy, and more advanced therapies like the aforementioned BRAF inhibitors. Dacarbazine, approved in 1975 by the FDA, continues to be the standard of care for most patients with this disease. The future may go towards combination therapies, like the currently in research combined therapy ipilimumab and nivolumab.
Another therapy currently being investigated offers a novel mechanism of action, an injectable formulation of Rose Bengal for the treatment of metastatic melanoma being developed by Provectus Pharmaceuticals, called PV-10. Rose Bengal is a water-soluble xanthene dye commonly used as eye drops to identify eye damage, by staining damaged conjunctival and corneal cells. Rose Bengal was found out to be selectively toxic to cancer calls via a process called chemoablation, whereby cells undergo a form of cell death that mimics both features of necrosis and apoptosis. PV-10 is a 10% solution of Rose Bengal formulated for intralesional injection (direct injection into the lesion).
The clinical development of this medicine has been positive thus far. Provectus released in 2011 positive initial data from a Phase II clinical trial of PV-10. 71% of the 80 participants achieved locoregional disease control (stable disease or better) in their injected lesions. Among individuals who achieved an observed response (49%) the average Progression Free Survival (PFS) was 11.7 months (the average life expectancy is 6 to 12 months). These positive results prompted the company to move along with the clinical development of PV – 10, and to present a poster, titled “Intralesional Injection with PV-10 Induces a Systemic Anti-tumor Immune Response in Murine Models of Breast Cancer and Melanoma,” at the American Association for Cancer Research (AACR) Annual Meeting in Washington, DC on April 8th.
Currently, Provectus is conducting a Phase III study for PV – 10. The study is anticipated to qualify as a pivotal trial, to support market approval in the US. 180 patients will participate in this study, designed to demonstrate delay or avoidance of progression of melanoma from a local disease to a life-threatening systemic stage. Hopefully with positive results and a meaningful impact on the lives of patients who suffer from this severe illness.