In Support of the Priority Review Voucher for Neglected Tropical Diseases

I'm tired of the Priority Review Voucher (PRV)-bashing. For those unaware of the PRV program, it is a new bipartisan incentive mechanism passed by Congress and signed into law in September of 2007. The legislation rewards the sponsor of a neglected tropical disease product with a tradable voucher upon its FDA approval. The voucher can then be used to obtain a priority (speedier) review for another product.Articles critical of the PRV program have appeared in the New England Journal of Medicine (NEJM), on Huffington Post, and, most recently, in a blast Healthnet email sent by Medicins Sans Frontieres (MSF). The last two of these were prompted by the Swiss pharmaceutical company Novartis applying for FDA approval of its antimalarial Coartem. The criticisms argue that Coartem is already WHO prequalified and sold in over 80 countries around the world, and that Novartis is only applying for FDA approval to obtain a voucher, with no intention of selling it in the United States.I would argue that Coartem is a great pilot candidate for the program and a good way to test how the whole system will work. Will there be value in the voucher? Will there be a market for the voucher? How will the FDA incorporate the legislation into its operations? Having Coartem as the pilot candidate for PRVs is much like pneumococcal vaccine being the first candidate for the Advance Market Commitment (AMC), instead of a more uncertain product. In order to establish the viability of the incentive, a dependable pilot is useful. Another apt analogy can be made. Novartis is being awarded the voucher on top of anything else it might receive in profits or good CSR for its successful investment in malaria R&D; this is analogous to the pay for performance (P4P) initiatives in health which have gained so much steam in recent years. It should also be noted that Novartis began the FDA registration process in 2006, a full year before the legislation existed.MSF argues that big pharmaceutical companies will abuse the legislation, scouring their pipelines and dusty shelves to register existing products they had no prior plans for. This is a flawed argument. The legislation specifically excludes combination therapies (where any active ingredient has previously been approved been FDA approved), and it will only award a PRV for a product that is either a significant improvement over the current treatment, or where no current treatment exists. This is why Novartis is the only company to come forward and apply for FDA approval thus far. It should also be noted that there are not dusty shelves full of neglected disease products; in fact, there are too few products for neglected diseases -- exactly why this incentive was created. Even if companies did come forward with these hypothetical, existing products, the vouchers would be a well deserved reward for investment in neglected diseases.A different criticism is put forth by Kesselheim in the NEJM. He argues that large pharmaceutical companies have not traditionally engaged in this sort of R&D, leaving it to smaller companies and biotechs. Kesselheim believes that the PRV program will sufficiently entice neither big Pharma to begin R&D in this area, nor the smaller companies normally involved in this research because they lack the more robust portfolio on which to use a prospective voucher. The first point is exactly correct, but the causality is wrong. The PRV program takes insufficient R&D from big Pharma as a given, hoping to make these R&D investments more attractive for large companies and change the landscape of neglected disease product development. On the second point, there is an easy answer: The voucher is fully tradable. Even for small companies who cannot afford to take a product through costly clinical trials and register it themselves, their pipelines are more valuable now that the PRV system is in place. It increases their chances of out-licensing a product to, or being bought by, big Pharma (two of the best outcomes for small companies and their investors).Despite its potential, the PRV program is not perfect. Critics are right to point out that the legislation does nothing in the way of assuring access to these products for those in the developing world who need them most. I would agree with them on this point, but hope that the recent surge in global health funding and investment would provide innovative financing schemes and product development avenues for these medical solutions to reach the poor once they are developed.No incentive scheme will be perfect, but the PRV program is an innovative mechanism to increase this much-needed R&D in neglected diseases. It is a unique way for the US to use its own market-based, profit oriented business model for the good of the developing world, and the U.S. Congress should be commended for this farsighted legislation. Despite the naysayers, if the PRV program results in just one neglected disease product making its way to the developing world that would otherwise not have even been discovered, then it will have to be judged a success.