Elephantiasis (lymphatic filariasis) causes severe swelling in the arms, legs, breasts or genitals that can become very painful, and river blindness (onchocerciasis) causes severe itching and bumps under the skin and is the second-most common cause of blindness due to infection.
According to an estimate, the diseases have affected 157 million people worldwide. The reason behind the diseases is parasitic worms.
There are few existing drugs available that can kill the worms. But they require weeks of treatment and can cause side effects or interact with other drugs.
Scientists at the University of Liverpool and the Liverpool School of Tropical Medicine and including Imperial College London, have developed a drug molecule that could reduce treatment duration and can effectively kill the cause of elephantiasis and river blindness.
The new molecule focuses on a species of bacteria called Wolbachia that lives inside the worms, which thusly live inside the human host. The worms depend on this ‘symbiotic’ association with the microbes for their improvement and survival. By focusing on these microbes explicitly, the particle is relied upon to have fewer side effects.
Professor Ed Tate, from Imperial’s Department of Chemistry, is Director of the Centre for Drug Discovery Science and led the work at Imperial. He said: “The mechanism we used is completely unique, and by identifying this new target we will reveal new insights into the bacteria-worm symbiosis. These insights could, in turn, be exploited to develop still more effective drugs against the worms, or even novel antibiotics to combat antimicrobial resistance in unrelated pathogens.”
in order to create the molecule, scientists screened 10,000 compounds in the search for candidates that affects the Wolbachia bacteria. They then designed several drugs that balanced efficacy at killing the parasite, human safety and the ability to be easily broken down in the body when taken as an oral drug.
Professor Steve Ward, senior author and Deputy Director of the Liverpool School of Tropical Medicine, said: “The identification represents the first potential designer drug of its kind, specifically targeting Wolbachia as a curative treatment for onchocerciasis and lymphatic filariasis.”
“The candidate selection status of this compound represents the successful conclusion to a multidisciplinary team’s efforts to generate the first synthetic drug specifically developed to target this bacteria and we are really excited to take the compound to the next stage of its development.”
The starting point for the work was screening activities of the A?WOL programme funded through the Bill and Melinda Gates Foundation, and the work at Imperial was funded by Collaboration Kick-start Funding by the Faculty of Natural Sciences. The team also partnered with Eisai Ltd, with additional support from AstraZeneca, which allowed the candidate drug molecule to be fast-tracked.
The article is published in Proceedings of the National Academy of Sciences.