We’ve completed the development of a new treatment for this debilitating disease
River blindness (onchocerciasis) is a disease caused by the parasitic worm Onchocerca volvulus, which is transmitted to humans through repeated bites from infected black flies. The resulting infection can lead to visual impairment and even blindness, severe itching, and debilitating and disfiguring effects on the skin, such as nodules.
people are at risk of infection
African countries are where the majority of infected people live
World Health Organization. Ending the neglect to attain the Sustainable Development Goals: A road map for neglected tropical diseases.
World Health Organization. 2020 WHO Onchocerciasis fact sheet.
people estimated to have vision loss due to the disease
The current standard treatment for river blindness is an anti-parasitic medicine called ivermectin. It has been generously donated by Merck & Co., Inc. (MSD outside of the United States) and distributed to areas in which the disease is endemic for over 30 years. But there are many areas where the prevalence of river blindness remains high, even with annual community-directed treatment with ivermectin.
Moxidectin is from the same class of drugs as ivermectin but due to its substantially longer half-life in the body, it suppresses the disease-causing microfilariae in more patients, more extensively and for longer. Moxidectin has a similar safety profile as ivermectin with both medicines well tolerated. The most common adverse events reported in Phase 2 and 3 studies were transient and self-limiting, generally occurring and resolving within the first week of treatment. Modelling studies suggest that moxidectin has the potential to significantly reduce time to elimination of this disease.
In 2018, we received US FDA approval for moxidectin for river blindness for people aged 12 years and older. We are now generating the additional data required to carry out community-directed treatment in endemic areas, through targeting World Health Organization (WHO) endorsement for use in river blindness treatment programs. We are also working on local regulatory approval in African countries and the evaluation of pilot implementation studies in several river blindness-endemic countries.
We are conducting a cutting-edge moxidectin pharmacokinetic modelling program in breastfeeding and pregnant women, to better estimate the impact of treating this group with moxidectin, as well as modelling to determine how moxidectin could reduce time to elimination of this disease.
Paediatric formulation studies are also underway to determine the best format for use in children under four years of age and others unable to swallow tablets.
Finally, we continue to explore the most effective ways of manufacturing and distributing moxidectin, to accelerate the elimination of river blindness.
Photo acknowledgement: Gbonjeima, Sierra Leone. Olivier Asselin, 2012.
A paediatric dose-finding study, a phase 3b trial comparing efficacy and safety of annual and biannual moxidectin or ivermectin treatment and mathematical modelling of moxidectin and ivermectin based elimination strategies to support country policy decisions.
Developing a paediatric formulation moxidectin for neglected infectious diseases.
A painful and debilitating disease of the lymph system affecting over 50 million people at any one time.
A soil-transmitted infection affecting up to 100 million people, particularly children.
A chronic infectious disease which may cause skin lesions and nerve damage found in 127 countries.