New treatment for human parasitic worm infections shows high efficacy
A compound previously used in veterinary medicine could greatly improve the treatment of parasitic worm infections in humans. Researchers at the Swiss Tropical and Public Health Institute report these findings in “The New England Journal of Medicine”. The Swiss TPH will now join forces with Bayer to further develop the drug.
17 May 2023 | Swiss TPH
Researchers at the Swiss Tropical and Public Health Institute (Swiss TPH) tested the efficacy and safety of the drug emodepside in a field study on Pemba Island in Tanzania. The aim is to control infections with parasitic worms that are transmitted through the soil, so-called helminths.
Soil-transmitted helminth infections are caused by different species of parasitic worms, including whipworms, hookworms and roundworms. Worldwide, more than 1.5 billion people are infected with at least one of these worms, with most of the infected population living in low- and middle-income countries.
Infected people can experience symptoms like stomach pain, diarrhea and anemia, while heavy infections can lead to malnutrition, impaired growth and physical development.
Safe drugs for the treatment of such infections are available but the efficacy varies widely. The current treatments recommended by the World Health Organization (WHO) are albendazole and mebendazole. However, in the case of the whipworm Trichuris trichiura, a single dose of these drugs can only cure 17 percent of the infected people as shown in this study. Moreover, as drug resistance is on the rise, new alternative treatments are urgently needed.
All patients cured
To fill the anthelminthic drug pipeline, Swiss TPH researchers have now tested the drug emodepside for the first time in humans infected with soil-transmitted helminths.
“In this study, emodepside showed high cure rates for all three soil-transmitted helminths,” says Emmanuel Mrimi, first author of the study. The lowest tested dose of 5 milligrams cured 83 percent of people infected with whipworm. “An increase of emodepside to 15 milligrams resulted in a complete cure for all people. Curing people infected with whipworm has never been achieved with the current anthelminthic treatments,” Mrimi explains. In addition, high efficacy was also observed against roundworms and hookworms.
“The drug also has other important characteristics. It is well tolerated and most adverse side effects in the trial were mild,” says Mrimi.
Collaboration with local partners
The study was conducted together with the Public Health Laboratory Ivo de Carneri, on Pemba Island, Tanzania. Overall, 442 study participants that were infected with one or more of the three main soil-transmitted helminths were enrolled. The participants were randomly assigned to emodepside, albendazole or placebo treatment groups.
Emodepside is an anthelminthic treatment used to date in veterinary medicine. “Drug repurposing is a key strategy in research for anthelminthic drug discovery and development that is neglected and underfunded,” says Jennifer Keiser, Professor of Neglected Tropical Diseases at the University of Basel.
The Swiss TPH has already tested the drug in laboratory studies. “Based on the promising results in the laboratory, we saw the potential for treating patients infected with soil-transmitted helminths,” says Keiser. That is why the drug was taken forward.
From innovation to application
“The recent results of the clinical trials are important and good news in the field of neglected tropical diseases. No new anthelminthic has been developed in the past decades. So this is a huge milestone towards controlling and eliminating soil-transmitted helminthiases,” Keiser adds.
The Swiss TPH will now join forces with the life science company Bayer on the further development of the drug. “The aim is to have it approved for use in humans and to make it available to patients in need in the future,” says Keiser.
Emmanuel C. Mrimi et al.
Emodepside for Trichuris trichiura and Hookworm Infection
The New England Journal of Medicine (2023), doi: 10.1056/NEJMoa2212825