On January 31, 2020 the Government Accountability Office (GAO) released a report on FDA’s Priority Review Voucher Programs (PRVs), covering the Neglected Tropical Disease (NTD PRV), Rare Pediatric (RPD PRV), and Medical Counter Measures (MCM PRV) Priority Review Voucher programs. The voucher programs were originally established and intended by Congress to encourage development of therapies for conditions that often lack the market opportunity to attract significant investment or may present other significant development obstacles and costs that may deter investment from biopharmaceutical companies.
The voucher program works by granting a priority review voucher to a drug developer who develops and gains approval for a therapy that treats a neglected tropical disease, a rare pediatric disease, or that is a medical countermeasure. A drug sponsor can later redeem the PRV when submitting a future drug application to treat any disease, or condition, or sell or transfer it to another drug sponsor. When redeemed, a PRV entitles a drug sponsor to priority review by FDA—which has a goal of a 6-month review, rather than the 10-month goal for a standard review.
The study was the result of a requirement included in the 21st Century Cures Act that compelled the GAO to review and report on the PRV programs. The GAO report is especially timely as the RPD PRV will begin to expire this year unless legislation makes the program permanent or extends the program sunset.
For the report the GAO interviewed FDA Officials, representatives from stakeholder groups, academic researchers, and drug sponsors and conducted a literature review of studies examining the voucher programs. The GAO also examined the number and types of vouchers that have been issued as well as the number of vouchers purchased, and for how much.
At a high level the results of the GAO report are mixed. Drug developers largely report that the voucher programs work as intended, incentivizing drug development in areas that were therapies would likely not have been developed. However, based on their literature review, of just three studies, one per voucher program, the GAO indicated that there is little evidence that the voucher programs have worked to incentivize the development of new therapies for neglected tropical or rare pediatric diseases, or medical counter measures. However, for the RPD PRV and the Medical Counter Measure PRV, the GAO failed to take into account the uncertainly of these two programs given that both programs are currently set to expire in the next few years.
Drug development is resource and time intensive. In fact, it has been estimated that it takes at least 10 years to bring a therapy from early development to approval. In the context of the voucher programs, a drug developer must first request designation from the FDA to be eligible for one of the voucher programs. The voucher is then not made available to the drug developer until the designated therapy is approved. However, with the PRV sunset looming, if a drug developer is unsure whether an incentive will be available when they will be eligible then the incentive is less effective. In other words, if a company is making the determination to initiate or continue a drug development program for a rare pediatric disease or a medical counter measure, but it is unclear whether the company would be able to get their development program far enough along in order to receive a voucher before the program expires, the voucher program is likely not going to serve as an incentive for that company. To really evaluate the impact of the voucher programs it is important that there is a long enough window for drug developers to reasonably develop and have their therapies approved, thus allowing them to qualify for a voucher.
To date, in fact since the establishment of the RPD PRV in 2012, more than 21 therapies have been approved for treating 18 rare pediatric diseases, including Duchenne muscular Dystrophy, spinal muscular atrophy, cystic fibrosis, and batten disease, among others. It’s also important to note that any developed and approved therapies that would allow a company to qualify for a PRV cannot have already been approved in the United States, meaning that they a new therapies being brought to American patients.
It’s so important that Congress extends the sunsets for the RPD and MCM PRV so that these programs can be fully evaluated for the impacts the we hope they have on the development of therapies for patients in areas where drug development is not sufficiently incentivized.