In 2007, Congress authorized a program intended to promote development of new treatments for neglected tropical diseases, conditions that disproportionately affect poor people in developing countries. Neglected tropical diseases lack treatments for many reasons, including attracting little interest from multinational pharmaceutical manufacturers, which preferentially invest in developing products that offer the possibility for more profitable returns. To help overcome such barriers, 2007 federal legislation offering priority review vouchers (PRVs) to companies that sponsored drugs newly approved by the US Food and Drug Administration (FDA) to treat qualifying neglected tropical diseases such as tuberculosis, malaria, schistosomiasis, and yaws. Once granted, the vouchers could be transferred or sold, or redeemed at the FDA to accelerate the regulatory review of a different product (eTable in the Supplement) from the standard 10-month period to the priority 6-month period intended to be reserved for drugs that appear to represent therapeutic advances.1 Earlier access to the US market leads to longer market exclusivity periods and greater revenues. In 2012, PRVs were also made available to sponsors of FDA-approved drugs treating a rare pediatric diseases, with a plan to reexamine the effects of the voucher program in this clinical context after 3 rare pediatric disease vouchers were granted.2