Chagas Disease Drug Now Available with FDA Approval

A new report from researchers at the Centers for Disease Control and Prevention (CDC) details the investigational use of a drug to treat Chagas disease now available commercially in the United States.

Chagas disease is a parasitic infection caused by Trypanosoma cruzi parasites. While mainly found in rural parts of Latin America, movements of individuals from rural to urban areas has led to a greater geographic spread of the disease. The disease can also spread through congenital transmission, blood transfusion, and organ transplantation. In the early acute phase of Chagas disease, an infected individual may be symptom-free or experience mild symptoms that are similar to other infections, such as fever, fatigue, body aches, headache, and rash. While symptoms typically go away without treatment within weeks or months, the infection can persist and lead to chronic infection, which, in about 30% of cases, results in cardiac or intestinal complications.

The antiparasitic medications benznidazole and nifurtimox are used for the treatment of acute, congenital, and chronic Chagas disease infections. Until the US. Food and Drug Administration (FDA) approved benznidazole in 2017 as the first treatment of Chagas disease in the United States for children ages 2 to 12 years, benznidazole and nifurtimox were exclusively available in the country through the CDC’s Investigational New Drug (IND) program. While benznidazole is now only available through the drug company Exeltis, a new report published in the CDC’s Morbidity and Mortality Weekly Report (MMWR) details the characteristics of patients included in the IND program from 2011 to 2018.

In October 2011, the CDC began providing benznidazole for the treatment of Chagas disease. The new report notes that most of the patients who received the drug through the IND program were chronically infected adults who had become infected in Latin America. Of the 369 total patients who received benznidazole in the program, 361 had chronic-phase infection. There were 319 (87.4%) patients born in 1 of 12 Latin American countries, primarily from El Salvador, Mexico, Bolivia, Guatemala, and Honduras. Of the 43 patients in the program born in the United States, the report noted at least 50% of these cases were likely from autochthonous, presumptive vector-borne transmission. The median age of patients was 42.9 years and only 34 patients were under the age of 19 years, which included 2 patients who were 2 to 12 years and 1 newborn with congenital infection.

In an interview with Contagion^®, the report’s lead author, Barbara Herwaldt, MD, medical officer of the CDC’s parasitic diseases branch, emphasized that that vector-borne transmission of Chagas disease remains low in the United States. “The FDA’s approval of benznidazole and the commercial availability of the approved product in the United States likely will increase awareness of Chagas disease and make it easier for patients with the disease to get this therapy, regardless of where they acquired the infection.”

For patients who cannot tolerate benznidazole, the CDC will continue to have nifurtimox available through the IND program and provide reference diagnostic testing for Chagas disease. Despite the presence of Chagas disease in the United States—both from immigrants and from an increase in the number of locally-acquired cases in states such as Texas—only a few states conduct active surveillance of the disease. The CDC recently called for better monitoring for Chagas disease, to better understand the prevalence of the underreported disease in the United States and to improve the public health response.