Priority Review Voucher - Limitations

Limitations

First, the voucher prize might be too small. Diseases with incredible burdens might merit more resources. The Advance Market Commitment, proposed by Michael Kremer and colleagues, calls for creating a $3 billion market for neglected diseases with high burdens, such as malaria, tuberculosis, and HIV/AIDS.

Second, the voucher prize might be too large, if it rewards research which would have been done anyway, or research with low value. Aidan Hollis of the University of Calgary notes that "firms which are developing very profitable products will be rewarded even more". While some treatments for neglected diseases are lucrative, this is generally not the rule, which is why the diseases are neglected.

Third, the voucher prize encourages innovation, but does not pay for access to existing therapies. Funding from governments or foundations might be needed to purchase treatments for poor people. Aidan Hollis of the University of Calgary has commented that the proposal does not address "the access problem, but helps to increase incentives through creating distortions in markets in developed countries".

Fourth, the voucher prize might tie up FDA resources. Fortunately, however, the law includes an extra fee paid by manufacturers to the FDA and requires that voucher bearers provide FDA with a year notice before using a voucher.

Fifth, priority review might not be safe. Priority review should not, however, be confused with accelerated approval or fast track. Priority review does not omit safety or efficacy studies or require approval within a given time frame. It sets a target of 6 rather than 10 months for FDA review. Nevertheless, if the FDA feels pressure to meet deadlines faster, it might be more likely to err. Carpenter and colleagues (2008) report that new molecular entities approved in the two months before the first review deadlines showed a higher rate of postmarketing safety problems than drugs approved at other times. Nardinelli and colleagues (2008) of the FDA, however, wrote that they were not able to replicate the findings and that the findings might be driven by HIV-AIDS therapies. Following the Nardinelli piece, Carpenter acknowledged several errors in their data set and demonstrated errors in the FDA's and Nardinelli's data; Carpenter and colleagues report that the original associations between last-minute approvals and safety problems hold.