FDA Approves First U.S. Treatment for Chagas Disease

Parasitic infection is caused by Trypanosoma cruzi

The FDA has granted accelerated approval to benznidazole (Chemo Research, S.L.) for use in children 2 to 12 years of age with Chagas disease—the first approved treatment for the disease in the United States.

Chagas disease, or American trypanosomiasis, is a parasitic infection caused by Trypanosoma cruzi and can be transmitted through different routes, including contact with the feces of a certain insect, blood transfusions, or from a mother to her child during pregnancy. After years of infection, the disease can cause serious heart illness, and it also can affect swallowing and digestion. While Chagas disease primarily affects people living in rural parts of Latin America, recent estimates are that there may be approximately 300,000 persons in the United States with Chagas disease.

The safety and efficacy of benznidazole were established in two placebo-controlled clinical trials in pediatric patients 6 to 12 years of age. In the first trial, approximately 60% of children treated with benznidazole had an antibody test change from positive to negative compared with approximately 14% of children who received a placebo. Results in the second trial were similar: Approximately 55% of children treated with benznidazole had an antibody test change from positive to negative compared with 5% who received a placebo.

An additional study of the safety and pharmacokinetics (how the body absorbs, distributes, and clears the drug) of benznidazole in pediatric patients 2 to 12 years of age provided information for dosing recommendations down to 2 years of age.

The most common adverse reactions in patients taking benznidazole were stomach pain, rash, decreased weight, headache, nausea, vomiting, abnormal white blood cell count, urticaria, pruritus, and decreased appetite. Benznidazole is associated with serious risks including serious skin reactions, nervous system effects, and bone marrow depression. Based on findings from animal studies, benznidazole could cause fetal harm when administered to a pregnant woman.  

Benznidazole was approved using the accelerated approval pathway, which allows the FDA to approve drugs for serious conditions where there is unmet medical need and adequate and well-controlled trials establish that the drug has an effect on a surrogate endpoint that is reasonably likely to predict a clinical benefit to patients. Further study is required to verify and describe the anticipated clinical benefit of benznidazole.

The FDA granted benznidazole priority review and orphan product designation. With this approval, benznidazole’s manufacturer, Chemo Research, S.L., is awarded a tropical disease priority review voucher in accordance with a provision included in the Food and Drug Administration Amendments Act of 2007 that aims to encourage development of new drugs and biological products for the prevention and treatment of certain tropical diseases.

Source: FDA; August 29, 2017.