2025-05-08T02:20:00Z

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Tens of millions of people across Africa are grappling with the devastating effects of parasitic worms that cause lymphatic filariasis, a debilitating disease commonly known as elephantiasis. This serious condition leads to significant swelling and deformities, particularly in the limbs and genitals, severely impacting the quality of life of those afflicted. Despite the implementation of extensive treatment programs aimed at reducing the transmission of lymphatic filariasis, it is concerning that hundreds of millions of individuals remain at risk of contracting this infection.

A recent clinical trial conducted in Côte d'Ivoire has shown promising results regarding a new treatment. Researchers from Washington University School of Medicine in St. Louis led this study, revealing that the anti-parasitic drug moxidectin, which is currently approved for the treatment of river blindness (another tropical disease caused by parasitic worms), outperforms the existing standard treatment, ivermectin, for lymphatic filariasis. Notably, moxidectin's long-lasting effects mean that individuals may require fewer treatment rounds compared to the annual regimen of ivermectin that typically spans at least five years. This advancement could significantly expedite the efforts to eradicate the infection across Africa.

The findings of this study were published on May 6 in The Lancet Infectious Diseases, shedding light on the potential of moxidectin as a game-changing therapy. Dr. Philip Budge, MD, PhD, an associate professor of medicine in the Division of Infectious Diseases at WashU Medicine and senior author of the study, emphasized the efficacy of moxidectin, stating, “Moxidectin really works much better than the drugs that we're currently using against lymphatic filariasis.” He also noted the co-endemic nature of lymphatic filariasis and river blindness across much of Africa, underscoring the necessity of an effective drug that can combat both diseases simultaneously.

The trial was conducted in partnership with the Centre Suisse de Recherches Scientifique in Côte d'Ivoire, a country where lymphatic filariasis is prevalent, leaving over 26 million people at risk. The disease is caused by the parasite Wuchereria bancrofti, which is transmitted through mosquito bites. River blindness, similarly, causes severe discomfort through symptoms like itching, rashes, and skin nodules, and can lead to vision impairment or even permanent blindness if left untreated. Efforts to eliminate these diseases are a priority for global health organizations such as the World Health Organization (WHO), which has facilitated the largest mass drug administration initiative to date, administering anti-parasitic medications to nearly 1 billion people.

In treating lymphatic filariasis, patients typically undergo a regimen of annual doses of ivermectin combined with another anti-parasitic drug, albendazole, over a span of five years to completely eradicate the infection. The focus of the recent study was to evaluate the effectiveness of moxidectin, a novel treatment for river blindness that has already been shown to outperform ivermectin in treating that condition, in combination therapies for lymphatic filariasis.

Participants in the trial included adults aged 18 to 70 who exhibited high blood concentrations of microfilaria, the larvae of adult worms responsible for the infection. Those with elevated levels are deemed infectious, which contributes to the ongoing transmission of lymphatic filariasis.

The study encompassed four treatment groups, with participants receiving either moxidectin or ivermectin in conjunction with one or two additional drugs typically used for treating parasitic worm infections. The results were promising; after 12 months, an impressive 18 out of 19 participants in the moxidectin and albendazole group successfully cleared their infections, in comparison to only 8 out of 25 in the ivermectin and albendazole group. At the 24-month mark, 14 out of 16 participants in the moxidectin group remained free of microfilaria.

Furthermore, among those who received either moxidectin or ivermectin alongside two other drugs, 21 out of 23 individuals in the moxidectin group were free of parasites after 24 months, while 20 out of 22 in the ivermectin group achieved the same outcome. These results suggest that a single dose of moxidectin, when combined with another treatment, is comparably effective to the traditional combination of ivermectin and two supplementary drugs.

Dr. Budge stated, “If you treat someone with moxidectin, they are more likely to clear their parasites for longer.” He contrasted this with ivermectin, which necessitates multiple doses over time, suggesting that moxidectin could be essential for reaching individuals who are typically difficult to treat repeatedly, especially those residing in remote areas.

Moxidectin was developed for human use by Medicines Development for Global Health, a not-for-profit pharmaceutical organization, in collaboration with the UNICEF/UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases (TDR). Dr. Budge expressed hope for the future, stating, “The best possible outcome for this work long-term would be for moxidectin to be used in mass drug administration programs.” He emphasized that the successful implementation of moxidectin in such programs could dramatically reduce the number of years required to achieve elimination of lymphatic filariasis. “There are hundreds of millions of people who won't have this disease in the future if we can eliminate it, and moxidectin may be able to help accelerate that process.”