$PVCT's PV-10: Update on an Emerging Melanoma Therapy

Via Provectus News, management informed shareholders and others about a Practical Dermatology article on PV-10 that included comments from principal investigator Dr. Sanjiv Agarwala, MD.

#1. Since those data were first reported, “There are now data for longer follow-up periods that show those initial results are holding up,” says Sanjiv S. Agarwala, MD, Professor of Medicine at Temple University School of Medicine in Philadelphia and Chief, Oncology & Hematology at St. Luke’s Cancer Center in Bethlehem, PA.

In Dr. Agarwala's poster presentation at ESMO 2012 in October, two key results were:

• Analysis of temporal data showed that Stage III subjects also experienced significantly greater mean Progression Free Survival (PFS) of at least 9.7 months, versus 3.1 months for Stage IV subjects (median PFS for Stage III subjects was not reached during the 12-month study interval); and
• Overall survival (OS) data were also presented by disease stage, with Stage III subjects achieving a mean overall survival of at least 12.6 months (median not reached during the study interval) versus 7.3 months for Stage IV subjects.

Dr. Agarwala appears to be commenting on data subsequent to that tabulated for and presented at ESMO, which he would have obtained from Eric this year for the Practical Dermatology article. Are PFS and OS results now longer? The question immunotherapies like PV-10 face is the durability (length) of the immune response they engender. From anecdotal comments, it seems industry folks wonder whether such immunotherapy responses last beyond (are durable for more than) 6-8 months. More and specific MM Phase 2 data will be presented at a Q3 medical conference. While we probably won't get specific data on durability of response (and perhaps updated numbers for PFS and OS) until then, I infer Dr. Agarwala's comments to mean durability of response has gotten better.

#2. Speaking of MM Phase 2 data, management observed notable local immunologic activity (in addition to systemic or distant immunologic activity), and should report on this significant finding in due course.

#3. “Right now we consider such a response to be a bonus clinically, and it is not something that the phase III trials will investigate.”

The contemplated MM Phase 3 trial has long been focused on a narrow or focused label for local regional disease control, with no thought of broadening the design or label that would present PV-10 as a systemic agent. The trial design's dosing regimen has been finalized. The application for breakthrough therapy designation is another regulatory path entirely.

#4. “Based on preliminary data, it appears that injection leads to local necrosis and recruitment of immune cells that may lead to a bystander effect,” Dr. Agarwala says. “We don’t have data to show the duration of immunological effects at this time,” he adds.

Dr. Agarwala appears to affirm preliminary results (interim analysis) of Moffitt's Phase 1 feasibility study are available, and positive.

#5. "Whereas most chemotherapeutic agents used in the management of melanoma tend to be administered by oncologists, PV-10 injection “is very doable in a dermatologist’s office,” Dr. Agarwala maintains. At some centers, physician assistants and nurse practitioners administer PV-10, a model that can be replicated in dermatology offices."

I've previously talked about the ease of PV-10 administration as a key piece of the drug's business value proposition. When I spoke to Dr. Agarwala last year, we discussed his experiences with and process of providing PV-10 in an oncology outpatient setting.