FDA Mulls “Fast Track” Approach For Priority Review Voucher Eligibility

FDA should consider setting up a process to pre-determine whether a product being developed for a neglected tropical disease will qualify for a priority review voucher, BIO Ventures for Global Health VP-Strategy & Operations Wendy Taylor said Dec. 12 at a public hearing convened by the agency.

"If there's a way to work with the respective review division and get an early pre-determination as to whether or not the product would qualify for priority review. ... I think that would be very, very helpful," Taylor said.

The priority review voucher program allows a company that receives approval for a drug to treat a neglected tropical disease to claim a six-month priority review on any other product it chooses.

But to qualify for the voucher, the NDA for the tropical disease drug must itself qualify for priority review. And under traditional agency procedures, sponsors are not told whether the application qualifies for priority status until it is submitted.

"So if you are a developer very early on in the process trying to decide whether or not to even undertake the risk of R&D ... whether or not your product will qualify for priority review seems to be a big unknown," Taylor noted.

"There is a lot of risk there, and the developers may not be willing to take the risk. If that happens, we think that could really undermine the program."

Taylor isn't alone in suggesting the idea of early priority review designation.

Duke Economics professor Henry Grabowski, one of the three academics who first proposed the voucher program in a 2006 article in Health Affairs, noted earlier this year that, as FDA mulls implementation, it may be useful to develop new rules rather than try to fit the voucher program into existing regulatory procedures (¹ (Also see "FDA Priority Review Voucher Guidance Coming: Incentive Has Low Visibility" - Pink Sheet, 13 Oct, 2008.), p. 32).

A draft guidance on the program issued by FDA in October is silent on the issue (² (Also see "Priority Review Vouchers One Step Closer, But Congress Must Act Again" - Pink Sheet, 27 Oct, 2008.), p. 28).

FDA convened the meeting to collect public comments to guide implementation of the program, and in particular on criteria to expand the list of diseases that could qualify for a voucher.

Agency officials at the meeting seemed receptive to the suggestion of pre-qualifying applications.

"What you're talking about sounds similar to what we do with Fast Track designation, where very early in development we can say it meets certain criteria, and if at the time of submission ... those criteria still hold, those are usually priority reviews," Office of Antimicrobial Products Associate Director of Regulatory Affairs David Roeder observed.

Not An Academic Issue

In the absence of a formal procedure, sponsors will have to rely on precedents to guide their thinking about whether they will be able to qualify for a voucher.

The first precedent came when FDA granted priority review status for Novartis' malaria drug Coartem (artemether/lumefantrine).

That decision encouraged PRV advocates, but it also prompted some criticism that Novartis is being rewarded with a voucher for a drug that is already widely used in the developing world (see ³ (Also see "Priority Review Vouchers: Coartem And The Importance Of Perceptions" - Pink Sheet, 22 Dec, 2008.)).

Assuming Coartem receives FDA approval as expected, there are two other combination malaria drugs likely to come before FDA soon: Ranbaxy's RBx 11160 (arterolane malate-piperaquine phosphate) and Pyramax (pyronaridine-artesunate), being developed by the University of Iowa and Shin Poong Pharma.

Those applications would provide an even clearer reading on how FDA is approaching priority status for voucher eligible products. With Coartem approved, the case for priority review could be tougher to make, especially for Pyramax which includes a close chemical cousin to one of the ingredients in Coartem.

- Jamie Hammon ([email protected])