Filarial diseases include onchocerciasis (also known as River Blindness), lymphatic filariasis (also known as elephantiasis), and loiasis. They are caused by parasitic worms which are transmitted by insect vectors to humans, mainly in Africa and Southeast Asia. About 168 million people are infected by the three diseases.

Among them, 120 million suffer from lymphatic filariasis and 25 million suffer from onchocerciasis. For 20 years, the treatment and control strategy for filarial diseases has been Mass Drug Administration programs based on drug donations directed by the World Health Organization, and designed to reduce morbidity and disease transmission. Despite the success of these programs in reducing prevalence in many countries, filarial diseases still prevail and challenges remain to achieve their elimination. The existing drugs used in MDA programs can take over a decade to work because they kill the juvenile form of worms but not the adult worms which carry on reproducing.

DNDi has a discovery and development program focused on screening for macrofilaricide drug candidates from repurposing libraries where compounds have previously been in development or reached registration for human and animal health.

One such candidate has already been identified and is progressing to the translation phase (pre-clinical testing):

Translation

• Emodepside is being explored though a material transfer agreement (MTA) between Bayer, Astellas and DNDi, as a potential macrofilaricide. It is a potent antihelminthic drug currently used in combination with praziquantel to treat parasitic worms in cats and dogs.

Other candidate macrofilaricide drugs have been identified and are being further investigated.