The ability of oxfendazole to attain higher blood levels than other similar drugs offers significant advantages for the treatment of certain kinds of helminth (parasitic worm) infections that have been difficult to cure. These infections are considered Neglected Tropical Diseases (NTDs) because, although they afflict millions of people in resource-limited regions, they have historically attracted little research into better treatment and control programs.
The Oxfendazole Development Group has initially prioritized three NTDs caused by helminths that we believe will benefit from access to oxfendazole.
- Fasciola hepatica: Fasciola hepatica, a helminth in the trematode class that infects the liver of millions of humans, causes a disease called fasciolosis. This is termed a zoonosis, because humans are not the primary host; it is typically an infection of livestock. Parasites shed by livestock into fresh water develop in snails and become attached to vegetation. If people eat vegetation containing the parasite, infection and disease can follow. One drug is primarily used to treat this parasite in livestock and humans, but resistance to it has become widespread and new treatments are urgently needed. Promising results have been obtained with oxfendazole in the cure of fasciolosis in sheep, using a single safe dose. Based on these (and other) results, we believe oxfendazole will be effective and safe in infected people and are pursuing clinical trials to test oxfendazole as a treatment for human fasciolosis in Peru.
- Taenia solium: A different parasitic helminth, the tapeworm Taenia solium, causes an NTD called neurocysticercosis in humans. This
parasite is also associated with livestock. Adult tapeworms of this species live in the intestinal tract of people who have eaten undercooked pork that contains a larval (immature) form of the parasite in structures called cysts. In the human gut, these cysts develop into adults, which then shed eggs into the environment where they can be ingested by pigs, developing into cysts in the muscle and other tissue of that animal. The presence of adult tapeworms in people produces almost no symptoms or disease. Problems occur if people eat the eggs; these develop into cysts in the person who ate them. Serious illness can occur if the cysts develop in the brain, causing neurocysticercosis, which is the major cause of adult-onset epilepsy. It is very difficult to eliminate the cysts with currently available drugs, but the high blood levels attained by oxfendazole are likely to change this. Indeed, studies in pigs infected with cysts indicate that oxfendazole is very effective and safe. We are collaborators in a clinical trial, again in Peru, to examine the ability of oxfendazole to cure neurocysticercosis in infected people. - Trichuris trichiura: We are also investigating the ability of oxfendazole to treat a human helminth infection called trichurosis, caused by a parasitic nematode (roundworm) called Trichuris trichiura, known as the whipworm. It is a human parasite (no animals involved) and is one of a set of parasitic nematodes called soil-transmitted helminths (STH), acquired from soil contaminated with their larvae. Hundreds of millions of people are infected with STH, which are the target of global chemotherapy-based control programs. Unfortunately, the whipworm is very hard to kill with the drugs in use, and so better drugs are needed. Based on studies in animals infected with close relatives of the whipworm, oxfendazole appears to be an excellent candidate, and the Oxfendazole Development Group is a collaborator in a trial of oxfendazole in humans infected with whipworms in Peru.
oxfendazoledevelopmentgroup.org 