The Impact of the Priority Review Voucher on Research and Development for Tropical Diseases

Abstract

Background: In 2007, the priority review voucher (PRV) was implemented in the US to incentivize research and development (R&D) for tropical diseases. The PRV is issued by the US FDA and grants a quicker review to manufacturers upon successful development of a product for a disease eligible for the program.

Objective: The objective of this analysis was to assess whether the PRV has incentivized R&D (measured as clinical trial activity) for the intended tropical diseases.

Method: We used a difference-in-difference-in-differences (DDD) strategy by exploiting variation in its implementation across diseases and registries around the world. Clinical trials were retrieved from the World Health Organization International Clinical Trials Registry Platform for the years 2005-2019.

Results: We found a positive, but not statistically significant, effect of the PRV on stimulating R&D activity. Delayed effects of the policy could not be found.

Conclusion: Our findings, which were robust across a series of robustness tests, suggest that the PRV program is not associated with a trigger in innovation for neglected diseases and therefore should not be considered as a stand-alone solution. It should be supplemented with other government measures to incentivize R&D activity. To increase the value of the program, we recommend that the PRV only be awarded to novel products and not to products that have already been licensed outside the US. Doing so would restrict the number of vouchers awarded and slow down their ongoing market depreciation. Finally, we propose that product sponsors be required to submit an access plan for PRV-awarded products.

Fig. 1

Eligible diseases of the priority review voucher program. Most diseases became eligible for the PRV when the policy was implemented in 2007. Few additional diseases were added to the eligible list later on, in 2014, 2015, 2016 and 2018. Source: Our elaboration on US FDA data [24]. PRV priority review voucher

Fig. 2

Total number of trials for each registry of the WHO ICTRP across eligible and non-eligible diseases (2005–2019). ANZCTR Australian New Zealand Clinical Trials Registry, CRIS Clinical Research Information Service, CTRI Clinical Trials Registry – India, ChiCTR Chinese Clinical Trial Registry, ClinicalTrials.gov United States registry, ICTRP International Clinical Trials Registry Platform, IRCT Iranian Registry of Clinical Trials, ISRCTN International Standard Randomised Controlled Trial Number, JPRN Japan Primary Registries Network, LBCTR Lebanese Clinical Trials Registry, PACTR Pan African Clinical Trial Registry, REBEC Brazilian Clinical Trials Registry, REPEC Peruvian Clinical Trial Registry, RPCEC Cuban Public Registry of Clinical Trials, SLCTR Sri Lanka Clinical Trials Registry, TCTR Thai Clinical Trials Registry