FDA Adds 4 Diseases to Tropical Diseases Priority Review Voucher Program

The US Food and Drug Administration (FDA) has announced the addition of 4 new tropical diseases to the Priority Review Voucher (PRV) program

The new tropical diseases that can qualify for the program include Lassa fever, chikungunya virus disease, rabies, and cryptococcal meningitis.

The addition to the program is to encourage the development of drugs and biologics to prevent or treat tropical diseases without suitable options.

Despite the uncommonness of these diseases in the United States, the FDA’s decision to include these diseases was influenced by the increase of international travel which can lead to easier transmission.

Additionally, these diseases are commonly found in lower income countries that lack the resources to develop effective treatments; this often leads to prolonged outbreaks. In Nigeria, 400 individuals fell ill with Lassa fever in an outbreak that sprung up earlier this year; 100 individuals died.

The tropical disease priority review voucher can be granted to a drug application that does not qualify for priority review, according to the FDA.

In order to gain tropical disease PRV, the drug must be for the prevention of a tropical disease listed by the FDA or if the FDA concludes that the tropical disease affects poor and marginalized individuals and does not have a significant market in developed nations.

Diseases previously added in the tropical disease program include malaria, tuberculosis, cholera, dengue, and Zika virus disease. Zika was one of the last diseases to be added in April of 2016.

The FDA indicated that all diseases submitted to the public docket between August 20, 2015 and June 20, 2018 as potential additions were considered, but not all diseases have been added to the list. In particular, the FDA reports that Pneumocystis pneumonia (PCP) has not been added as a disease that qualified for the tropical disease PRV program, despite the fact that it is considered a public health threat by the US Centers for Disease Control and Prevention (CDC).

PCP is a fungal infection that is common in individuals who have weakened immune systems or take medicines that affect the body’s ability to fight germs and sickness. The CDC indicates that there is no preventative vaccine for PCP, but health care providers can prescribe preventive medication such as trimethoprim/sulfamethoxazole to individuals who are considered to be at increased risk of infection.

In a statement explaining the decision not to include PCP, the FDA said: “In sum, although PCP disproportionately affects poor and marginalized populations, it is an infectious disease for which there is a significant market in developed nations for drugs indicated for prevention of PCP.”