More info from ASCO....PV-10...Rose Bengal for melanoma....

I think PV10 (a 10% Rose Bengal solution) is a very interesting approach for melanoma patients with dermal and subcutaneous tumors.  I've been reporting on it for the past couple of years as data has become available and will list my prior posts at the bottom of this one so you can follow the history of it yourself if interested.

Here's a synopsis of the latest out of ASCO:

Efficacy of intralesional Rose Bengal in patients receiving injection of all existing melanoma in phase II study PV-10-MM-02

2014 ASCO abstract No: 9027, Authors:  Agarwala, Thomplson, Smithers, et al....St. Lukes in Easton, PA;  University of Sydney, Sydney, Australia; Brisbane Hospital, Brisbane, Australia; MD Anderson, Houston, TX; University of Louisville, Lousiville, KY; California Pacific, San Fran, CA; Provectus Pharm, Knoxville, TN.

Safety and efficacy of intralesional treatment of cutaneous melanoma with rose bengal (PV-10) was evaluated in an 80 patient international, multicenter, single arm phase II trial. Patients with a median of 6 previous interventions and a 6.3 cm median sum lesion diameter in biopsy confirmed melanoma, were given PV-10 into up to 20 cutaneous and subcutaneous lesions up to 4 times over a 16-week period and were followed for 52 weeks.  RESULTS:  In the subgroup of 28 patients who received PV-10 into all existing melanoma lesions (therefore had NO un-injected lesions) the overall response rate was 71% with 50% experiencing a complete response.  In these patients with all disease injected plus 26 other patients with uninjected disease limited to by-stander lesions - complete response was achieved in 232 of 363 injected lesions.  121 lesions required a single injection for complete response, 84 required 2 injections, 22 required 3, and 5 required 4 injections.  Additionally, 10 of 28 UN-INJECTED bystander lesions achieved complete response.  CONCLUSIONS:  The high rate of symptom control in refractory patients, manifested in a complete response of injected lesions after minimal intervention, is the basis for a breakthrough therapy application based on the 28 patient "all treated" subgroup.  Although the primary ablative effect is responsible for complete response in injected tumors, durability of response and bystander response implicate an immunologic mechanism of action secondary to ablation.

Assessment of immune and clinical efficacy after intralesional PV-10 in injected and uninjected metastatic melanoma patients.

2014 ASCO abstract No:  9028, Authors:  Sarnaik, Crago, Weber, et al...of Moffitt, Tampa, FL

Intralesional therapy is under investigation to treat dermal and subq mets in melanoma. In mice...injection of PV-10 (10% rose bengal) induced regression of injected and uninjected "bystander" lesions.  We observed a consistent increase in anti-tumor T cell responses following injection of PV-10 in the mouse model....so:  A pilot clinical trial enrolled 8 patients.  Two study lesions in each patient were sampled by biopsy pre-treatment; one of the two lesions was injected with PV-10, then both residual sites were completely excised.  We compared tumors before and after treatment with staining and MelanA immunohistochemistry.  Blood samples were studied before and after injections were done.  RESULTS:  Treatment with injected PV-10 led to a complete response when the removed tumors were examined as a pathology sample for both the injected AND uninjected (bystander) lesions in 4 of the 8 patients.  In all 8 patients...examination of both of their removed tumors....showed at least partial regression of the injected lesion.

SO...in HALF the patients, both of their tumors (injected and noninjected) had a complete response.  In all 8 of the patients, the injected lesions had at least a partial response.

NOTES: Blood work demonstrated a statistically significant increase in circulating cytotoxic T cells.  Patient history = 6 of 8 patients treated with PV-10 had metastatic disease refractory to prior ipi, anti-PD1 and/or vemurafenib therapy.  4 of these 6 patients demonstrated complete response in both their injected and uninjected tumors on the pathology exam. 

Hmmmm....wonder (not that it really matters) how long the injected tumors were left in place, before both tumors were removed??  Though these are clearly small numbers....and change from patient data to tumor by tumor data in the first report can be confusing...it seems to me that this approach could provide significant relief if not eradication of disease in some.  Best - c

Rose Bengal/PV 10 - 2012

Rose Bengal/PV 10 - 2013

Rose Bengal/PV 10 - 2014