Drug Shows Promise Against Chagas’ Disease

Times Staff Writer

An experimental drug has shown promise as the first effective therapy for Chagas’ disease, a widespread affliction in Latin America that kills 50,000 people annually, scientists reported Wednesday.

The antifungal agent TAK-187 was effective in the treatment of infected mice and didn’t cause the toxic side effects of existing drugs, according to a study in the April issue of the journal Antimicrobial Agents and Chemotherapy.

The researchers said they intended to begin human trials of the drug as soon as possible.


“If this is a drug that can be given orally, and if it turns out to be safe in other animal models -- dogs and primates, whose metabolisms are more like people -- then it would be a real breakthrough,” said James McKerrow, a Chagas expert and pathology professor at UC San Francisco.

Chagas’ disease affects 16 million to 18 million people in Latin America, according to the World Health Organization. It rarely causes symptoms until 10 or more years after infection, when it attacks the bones and heart. Many victims die from heart failure.

Researchers at the Venezuelan Institute for Scientific Research and the National University of Salta in Argentina conducted the study with funding from the Howard Hughes Medical Institute, based in Chevy Chase, Md.

Chagas’ disease is caused by a microscopic parasite, Trypanosoma cruzi, which is usually passed to victims by the bite of a bloodsucking insect called the assassin bug.

The nocturnal insect lives in the crevices of mud or thatched houses and feeds with a long proboscis that penetrates the skin, said Erwin Huebner, a zoology professor at the University of Manitoba in Canada.

TAK-187 eliminated the parasite from mice by blocking production of the steroid ergosterol, which plays a crucial role in the parasite’s life cycle. The researchers observed that the drug was effective at one-tenth the dose of the currently used anti-Chagas drug, benznidazole, and could be given less frequently.

McKerrow said benznidazole is often ineffective and can cause crippling side effects, such as nerve and bone marrow damage.

Even if human trials are successful, it could still be years before TAK-187 is widely used. Because of the low profit potential of drugs employed to treat diseases endemic to developing countries, such medications typically must be brought to market by international or nonprofit groups.

“Only 1% of the new drugs introduced to the market in the last 25 years were developed to treat tropical diseases,” Julio A. Urbina of the Venezuelan institute, one of the authors of the study, said in a written statement.