New Anti-Parasitic Drug Moxidectin Shows Promise in Fighting Lymphatic Filariasis in Africa

Tens of millions of individuals across Africa are afflicted with parasitic worms that lead to lymphatic filariasis, commonly known as elephantiasis. This debilitating disease causes significant swelling and deformities in the limbs and genitals. Despite various treatment initiatives that have successfully reduced the risk of contracting the disease, a substantial number of individuals remain susceptible to infection.

A recent clinical trial conducted in Côte d'Ivoire by researchers from Washington University School of Medicine has found that the anti-parasitic medication moxidectin--currently used to treat river blindness--demonstrates greater efficacy against lymphatic filariasis compared to the standard treatment, ivermectin. Notably, moxidectin's prolonged effects may result in fewer treatment cycles, potentially expediting the elimination of this infection in Africa.

This study, published in The Lancet Infectious Diseases, highlights the significant advantages of moxidectin. Dr. Philip Budge, an associate professor in the Division of Infectious Diseases at Washington University, emphasized the need for effective treatments in regions where lymphatic filariasis and river blindness are co-endemic.

Lymphatic filariasis remains a pressing health concern in numerous African nations, with over 26 million people identified as at risk in Côte d'Ivoire alone. The disease is transmitted by mosquitoes carrying the parasite Wuchereria bancrofti.

In addition to the physical deformities caused by lymphatic filariasis, the disease increases the likelihood of contracting other serious illnesses such as malaria, tuberculosis, and HIV/AIDS. Traditionally, patients are required to undergo annual treatments with ivermectin and another anti-parasitic drug, albendazole, for five consecutive years to eradicate the infection fully.

The objective of this particular study was to evaluate whether moxidectin, which has proven superior in treating river blindness, could serve as a more effective option for lymphatic filariasis when used in combination therapies. Participants in the trial were adults aged 18 to 70 with high concentrations of microfilaria, the larvae of the adult worms, indicating their infectious status.

The trial comprised four groups, each receiving different combinations of moxidectin or ivermectin with one or more additional anti-parasitic medications. Results revealed that after one year, 18 out of 19 participants who received moxidectin alongside albendazole cleared their infections, compared to only 8 out of 25 in the ivermectin plus albendazole group. Remarkably, 14 out of 16 participants treated with moxidectin remained free of microfilaria after two years.

Among those who received either moxidectin or ivermectin combined with two other drugs, 21 out of 23 individuals in the moxidectin group were parasite-free after 24 months, while 20 out of 22 participants in the ivermectin group achieved similar results. These findings suggest that a single dose of moxidectin paired with another medication may be as effective as multi-drug combinations involving ivermectin.

Dr. Budge noted that moxidectin's ability to provide longer-lasting parasite clearance could be particularly beneficial for reaching populations that are often overlooked in mass drug administration efforts, especially those residing in remote areas.

Moxidectin was developed for human use by Medicines Development for Global Health in conjunction with the UNICEF/UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases. Dr. Budge expressed optimism that moxidectin could be integrated into mass drug administration programs, significantly reducing the time required to eliminate lymphatic filariasis. The successful elimination of this disease could potentially improve the lives of hundreds of millions of individuals in the future.