A new chemical could provide an effective treatment for three parasitic diseases for which previously there were no viable treatments. These diseases, which together affect more than 20 million people mainly in Africa and Latin America and cause more than 50,000 deaths annually, had no effective treatments and were assigned to the ‘neglected diseases’ category.
One reason for the general neglect was the reluctance of large pharmaceutical companies to invest money and material into research on these illnesses, as they were considered a ‘poor-man’s disease’ and companies did not foresee recouping their investments.
The three diseases, Chagas disease (American trypanosomiasis), Sleeping sickness (African trypanosomiasis) and Leishmaniasis , are caused by infection from parasites that have similar biology and genetic structure, potentially enabling them to be cured by a single class of drug. While there are some drugs to treat the infections, they are expensive and toxic and often need to be given via an intravenous drip, making them impractical in poor regions.
Now scientists working with the World Health Organization (WHO) and the pharmaceutical company Novartis have identified a new enzyme, common to all three parasites, and developed a chemical that binds to a ’target’ enzyme in the parasite that prevents it from becoming active. But crucially the chemical does not affect similar processes in mammalian cells.
Codenamed GNF6702, the new drug is now entering safety tests before human trials. Chagas disease which is transmitted to humans by bloodsucking bugs affects 6 to 7 million people worldwide, mostly in Latin America. It causes damage to the heart and central nervous system.
African trypanosomiasis (Sleeping sickness) is a disease found affecting around 30,000 people in sub-Saharan Africa and is transmitted by the tsetse fly. It infects the brain, causing victims to fall into a coma and die; animals such as cows may also become infected by the same parasite.
Leishmaniasis, which occurs in many parts of the tropics, sub-tropics and southern Europe, affects nearly 1.2 million people. Transmitted by the bite of sand flies, it results in two forms of the disease: Cutaneous leishmaniasis that cause skin sores and Visceral leishmaniasis that affects several internal organs.