Evaluate fusidic acid as a potential short-course treatment for onchocerciasis

Founded: 2025

Fusidic acid is a widely available antibiotic from the fusidane class with known anti-Wolbachia properties. Unrelated to penicillin, fusidic acid has been in use for over 40 years and is primarily used to treat bacterial skin infections as well as chronic bone and joint infections. The Fusidic Acid Macrofilaricide Evaluation (FAME) project aims to evaluate fusidic acid as a potential short-course treatment for river blindness (known as onchocerciasis), particularly in regions co-endemic with Loa loa (African eye worm), where treatment with ivermectin is contraindicated.

Wolbachia is an intracellular bacterium that lives symbiotically within the filarial parasite that causes river blindness and is essential for the survival of adult filarial worms. Anti-Wolbachia drugs, such as doxycycline, work by depleting or killing the Wolbachia bacteria, which are essential to the survival of adult filarial parasites. This leads to the sterilization of female adult worms, the gradual death of adult worms, and reduced inflammation and pathology in humans living with onchocerciasis.

While ivermectin remains the backbone of mass drug administration programmes targeting river blindness, it does not kill adult worms, requires repeated dosing over several years, and carries a risk of severe side-effects in people also living with Loa loa. Anti-Wolbachia therapy is preferable for individual treatment of river blindness in Loa loa co-endemic areas and in cases of ivermectin resistance. The best-known anti-Wolbachia treatment, doxycycline, has a long treatment duration and is contraindicated in young children and pregnant women.

The FAME trial is testing regimens as short as 7 to 14 days, compared to 4 to 6 weeks for doxycycline, and 12 or more years of ivermectin annually. If proven effective, fusidic acid’s shorter treatment duration, expected safety in Loa loa co-endemic areas, and low cost would make it a more feasible option for mass deployment, especially in remote or resource-constrained settings. Furthermore, current evidence shows that, depending on the dosage and formulation, fusidic acid could be a safer treatment option for children and pregnant or breastfeeding women living with river blindness.

The FAME trial is being conducted by an international consortium of partners, including DNDi, the University of Buea (Cameroon), the University of Bonn (Germany), and the Liverpool School of Tropical Medicine (UK). The project supports training and capacity strengthening for early-career scientists in sub-Saharan Africa and involves validating cutting-edge technologies such as AI-assisted histological analysis tools and molecular biomarkers for Wolbachia depletion.