Data for PV-10 in Melanoma to be Presented at European Cancer Congress
09/13/2013
Analysis of data from Provectus Pharmaceuticals, Inc.'s completed Phase 2 study of intralesional PV-10 in metastatic melanoma will be presented at the upcoming European Cancer Congress (ECCO 17- ESMO-38 - ESTRO 32), taking place September 27 through October 1, 2013 in Amsterdam, The Netherlands.
The international, multicenter, Phase 2 study of 80 subjects with AJCC Stage IIIB-IV melanoma examined the effect of up to four treatment cycles of intralesional (IL) PV-10 in patients with refractory, locally advanced disease. Interlesional PV-10 tumor ablation provided, with minimal intervention, rapid locoregional disease control. The high rate of bystander lesion response and reversible cutaneous locoregional blistering (prognostic for patient response), are consistent with the novel tumor-specific immune mediated mechanism of action of PV-10.
PV-10 is a 10% solution of Rose Bengal under investigation as a novel cancer therapeutic, is designed to selectively target and destroy cancer cells without harming surrounding healthy tissue, minimizing potential for systemic side effects.
Abstract No. 3755 is available for viewing online.
In the phase 2 study, up to 10 cutaneous or subcutaneous target lesions and up to 10 additional non-target lesions received intralesional PV-10 at day 0 and could be reinjected as necessary at weeks 8, 12 and 16 if tumor tissue remained. Up to 2 additional cutaneous or subcutaneous lesions were left untreated to assess bystander response. The primary endpoint in the single arm trial was best overall objective response rate (BORR) judged by RECIST in each subject's target lesions.
Results showed that for all subjects, BORR was 51% (26% CR, 25% PR) with the amount of tumor burden accessible to PV-10 injection prognostic for outcome. In the majority of subjects (66%) the lesions treated with PV-10, together with up to two untreated bystander lesions, constituted all disease present, and these subjects achieved a BORR of 62%. In subjects where all disease was treated (33% of subjects) BORR further increased to 73%.
The new data analysis described in Abstract No. 3755 further examines these response rates relative to a specific reaction, locoregional blistering, observed in 40% of subjects. This phenomenon, which generally occurred within seven days of PV-10 injection but with no clear pattern of incidence, typically resolved within four weeks. Appearance of this potentially immune-mediated effect was strongly predictive of outcome. Subjects who developed blisters had 66% BORR vs. 42% for those not developing blisters. The correlation between occurrence of blisters and locoregional disease control was even stronger. Among subjects with blisters, 90% achieved stable disease or better vs. 54% of subjects without blisters. The researchers conclude that for patients who are refractive to other local treatments such as surgery and radiation, intralesional PV-10 provides a viable strategy to maintain locoregional control of the disease with minimal intervention, and can potentially delay, reverse or prevent progression to life-threatening visceral disease.
Sanjiv S. Agarwala, MD, Principal Investigator for the Phase 2 trial of PV-10, and Chief of Medical Oncology and Hematology at St. Luke's Hospital and Health Network in Bethlehem, PA, will present the detailed findings of this exploratory analysis during the Poster Session on "Melanoma and Skin Cancer” scheduled for Monday, September 30, 2013 from 9:30 a.m. to 12:00 noon.