Fisking Provectus' Claims About PV-10's FDA Approval Path
Provectus Biopharmaceuticals (PVCT: Pink Sheets) now says it will submit data from its phase II study of the melanoma drug PV-10 to the FDA, seeking breakthrough therapy designation (BTD), as expected.
As expected? Sure, because as I've already made clear, Provectus has been unable and/or unwilling to start the phase III study of PV-10 in melanoma for the past two years, as promised. Consider this BTD filing, which will be completed later this quarter, a Hail Mary. The ball is now in the air for the next 60 days as FDA mulls the PV-10 BTD request and reaches a decision.
By the way, BTD does not equal drug approval. Nowhere in today's update does Provectus confirm that FDA will allow an approval filing or actual review for approval PV-10 based on a tiny phase II study, even if BTD is granted. BTD in the absence of well-designed clinical trials demonstrating clear efficacy and safety doesn't mean much.
Did FDA actually encourage Provectus to seek BTD status for PV-10? Here's what the Provectus press release says:
In reference to discussions on the potential for breakthrough therapy designation, "FDA advised Provectus to provide objective response rates with adequate information to evaluate the symptomatic treatment effects (e.g. pain, infection, bleeding) in patients presenting with locally advanced cutaneous melanoma who received PV-10 to all lesions."
I don't see anything in that statement where FDA says, "Sure, definitely, go ahead and file for BTD!!!" It sounds a lot more like, "Sure, if you want to file for BTD, go ahead. We can't stop you."
I spoke briefly with Provectus COO Peter Culpepper a few minutes ago. He wouldn't comment further on what the minutes from the FDA meeting actually say about BTD. The company is also not making the FDA meeting minutes publicly available, he says.
Culpepper, of course, is excited about the new regulatory plan for PV-10, insisting the agency is being supportive and recognizes that PV-10 would be an entirely new treatment for patients with localized, advanced cutaneous melanoma i.e. patients with skin cancer is fully accessible to treatment with an intra-lesion injection.
How many patients in Provectus' phase II study fit this category, meaning all their lesions were injected with PV-10?
Twenty-eight patients, said Culpepper.
So, Provectus is basing its BTD and approval strategy largely on a subset of 28 patients from an already small 80-patient phase II study. Provectus warns that it may need more clinical data:
The Agency may yet recommend and it may be in the best interest of Provectus to undertake a small, short bridging study in patients where all tumor burden can be injected. This would allow more frequent dosing than was permitted in the Phase 2 study, presumably akin to the dosing schedule currently used to treat nearly 100 patients under our expanded access protocol, and allow symptomatic endpoints to be prospectively correlated with objective response criteria.
Translated: It sounds like FDA told Provectus that it may need to run another phase II study before it runs the larger phase III study proposed two years ago. This helps explain why Provectus held the December meeting with FDA in the first place, and why the development of PV-10 has been so delayed.
How is treatment and clinical benefit of PV-10 being defined?
"Symptom control," said Culpepper, which Provectus defines as improvement in pain, infection or significant bleeding. Symptomatic control of melanoma is a far cry from a cure or even the delay or prevention of melanoma metastasis -- data the company doesn't have.
This story will continue...