Jennifer Keiser
Associate Professor and Head of Helminth Drug Development, Swiss Tropical and Public Health Institute (Swiss TPH)
Lack of investment in developing drugs against parasitic worm infections results in limited treatment options and a growing threat of drug resistance. Combining or repurposing drugs can help overcome this problem.
Anthelmintic drugs are crucial in the fight against parasitic worm infections — which affect over 1.5 billion people worldwide — particularly for those living in poverty. These drugs treat infections caused by different species of parasitic worms including whipworms, hookworms and roundworms — the three main soil-transmitted helminths that can cause debilitating diseases.
Challenges in treating parasitic worm infections
The current pipeline of anthelmintic drugs is insufficient to meet the global demand for effective treatments. This is partly because parasitic worm infections have been neglected by the pharmaceutical industry, as there are few incentives for drug development given the low profitability.
To treat soil-transmitted helminth infections, albendazole and mebendazole are currently used; but both drugs have limitations and demonstrate low efficacy against whipworm infections. However, no new anthelmintic has been developed in four decades.
Another challenge is the threat of resistance to existing drugs. This is particularly concerning given the limited number of drugs available and the fact that resistance can develop rapidly in response to the widespread use of these treatments, as observed in animal health.
Several veterinary drugs might be an attractive starting point for treating infections in humans.
Strategies to fill the anthelmintic pipeline
One promising area of research we are working on at the Swiss Tropical and Public Health Institute (Swiss TPH) is testing new combinations of existing drugs. They have the potential to target multiple species of helminths given their broader spectrum of activity. Additionally, drug combinations can increase efficacy and reduce resistance.
Another area of research is the repurposing of veterinary drugs for human use. Several veterinary drugs might be an attractive starting point for treating infections in humans. For example, emodepside — an anthelmintic drug used for dogs and cats — is undergoing clinical testing with promising results. Repurposing could provide a cost-effective way to expand the pipeline of available treatments.
Only one piece of the puzzle
Investment in the anthelmintic pipeline is critical to reducing the burden of disease and preventing drug resistance. By combining existing drugs or repurposing veterinary drugs for human use, we can help to ensure that effective treatments are available to those who need them — and that they remain effective for years to come.
New drugs are only one piece of the puzzle. To truly reduce the burden of these diseases, an integrated approach is needed, which includes improved water and sanitation infrastructure, education and behaviour change.