Moxidectin

The macrocyclic lactone moxidectin is an anthelmintic drug, which means that it is used to control or prevent parasitic worms (helminths). Its principal use is veterinary, in animals ranging from dogs and cats to cattle and horses. Parasites susceptible to moxidectin include Strongylus vulgaris (“blood worm”) in horses and Ostertagia ostertagi (“brown stomach worm”) in cattle.

Moxidectin, obtained from Streptomyces bacteria, was developed in the 1980s by the now-defunct American Cyanamid Co. Today, it is marketed worldwide under several trade names by major pharma companies such as Bayer Animal Health, Pfizer Animal Health, and Zoetis.

This year, on the basis of only two double-blind studies, the US Food and Drug Administration approved the use of moxidectin on humans. The target disease is river blindness (onchocerciasis), which occurs mainly in sub-Saharan Africa. The disease is caused by the parasitic worm Onchocerca volvulus, which is disseminated by Simulium species of black flies.

Moxidectin was registered by the nonprofit Medicines Development for Global Health (MDGH) with guidance from a World Health Organization initiative. MDGH is the first nonprofit to register a tropical medicine drug through FDA’s priority review voucher program.