A group of health advocacy organizations are calling on the Senate Committee on Health, Education, Labor and Pensions (HELP) to tighten requirements for obtaining priority review vouchers for drugs for tropical diseases.
In a letter addressed to HELP Committee Chairman Lamar Alexander (R-TN) on Tuesday, seven organizations including Médecins Sans Frontières (MSF), Drugs for Neglected Diseases Initiative (DNDi), Center for Global Health Policy, TB Alliance, Treatment Action Group (TAG), American Thoracic Society (ATS) and the Sabin Vaccine Institute say that changes are needed to appropriately incentivize the development of new treatments for tropical diseases.
Tropical diseases, also called neglected tropical diseases (NTDs), are diseases such as malaria, Dengue fever or Ebola virus that only occur in, or are more prevalent in, developing countries. Because these diseases primarily affect low-income regions of the world, it is difficult for companies to recover their research and development costs.
To incentivize drug development for these diseases, the Food and Drug Administration Amendments Act of 2007 (FDAAA) created a system for awarding priority review vouchers to companies that successfully develop drugs for NTDs. When redeemed, these vouchers allow a company to have a future product reviewed in just six months instead of 10.
Congress initially made 16 NDTs eligible for the vouchers, though in 2014 it acted to add Ebolavirus, Cuevavirus and Marburgvirus to the list. Under FDAAA, FDA can also add diseases to the program, which the agency did for the first time in August 2015.
|Eligible Diseases Under the Tropical Disease Priority Review Voucher System|
|Dengue/Dengue haemorrhagic fever||Dracunculiasis (guinea-worm disease)|
|Fascioliasis||Human African trypanosomiasis|
|Schistosomiasis||Soil transmitted helminthiasis|
|Added by Congress|
|Added by FDA Order|
To learn more about priority review vouchers, see our Regulatory Explainer on the subject.
Calls for Change
In July 2014, MSF, DNDi and the TB Alliance wrote to the Senate HELP Committee highlighting four issues with the priority review voucher program:
- The economic value of the program is still unclear.
- A [voucher] can be awarded even when public health treatment needs have not been met by the entity receiving the award.
- The [voucher] does not include any mechanism to ensure patients will have affordable and appropriate access to [the] products.
- Not all neglected diseases are explicitly eligible.
In the new letter, the group says that some of its concerns about the economic value of the program and number of eligible diseases have been alleviated, citing the recent sale of United Therapeutics' voucher to AbbVie for $350 million and additions to the list of eligible NTDs by Congress and FDA.
However, the group is calling for the program to be amended to include two key provisions. First, the group says that vouchers "should only be awarded to products that are truly new, or that are registered with the FDA in a timely manner after initial registration in disease-endemic countries." This is because two of the vouchers awarded so far "were for drugs already in use for a long time in other countries."
This isn't the first time the program has been criticized for not incentivizing new research into treatments for NTDs. Earlier this year, Harvard professor Aaron Kesselheim questioned whether the program actually increased research and development into NTDs.
Second, the group says companies should be obligated to develop an access strategy to ensure treatments granted vouchers are both affordable and accessible to the patients who need them.
Under current legislation, companies are not required to price treatments which are awarded vouchers affordably and there is no requirement that companies actually market the product after it is approved.
The group points to miltefosine, for which Knight Therapeutics was awarded a priority review voucher in 2014, saying that many organizations and governments "are still struggling to access [miltefosine] at an affordable price – or in some cases to access it at all."