This parasite infects an estimated 1.2 million people a year, primarily poor people who live in sub-tropical regions. Partly due to global warming, this disease has now spread to southern Europe.
In 2021, the Drugs for Neglected Diseases initiative (DNDi) ‘won’ the Call for Proposals for Skin Neglected Tropical Diseases with its research into cutaneous leishmaniasis (CL). The disease is spread by parasites, which are transmitted through the bite of the sand fly. This parasite infects an estimated 1.2 million people a year, primarily poor people who live in sub-tropical regions. Partly due to global warming, this disease has now spread to southern Europe. The disease is not fatal, but in the more severe cases it can lead to disfigurement and as a result to stigmatisation.
Research director Charles Mowbray and his international multidisciplinary team (including researchers from the Netherlands Cancer Institute NKI) will work on a three-year project to find an inexpensive, accessible treatment with few side effects. ‘The existing medication against CL is toxic, antiquated and insufficiently tested in clinical trials,’ Mowbray explains. ‘Their efficacy varies from region to region and depends on the nature of the disease. In fact, the sand fly is known to transfer an estimated 20 different subspecies of these parasites, each one producing its own distinct symptoms. Moreover, existing medication often has serious side effects, which tend to undermine patients’ commitment to treatment.’
Since neither the pharmaceutical industry nor policy-makers consider CL to be a priority, there has been a lack of in-depth research on how to tackle the various parasites. DNDi aims to fill that gap. ‘Currently, we have two very promising new drugs which we want to develop further. We will now test these using a mouse model. For example, we will examine the level of drug penetration in the various layers of the skin and assess how these parasites react. The initial findings are promising, but we still need to gain a better understanding of the data before we can actually start testing both drugs on people.’ When the pre-clinical testing is completed, then the clinical trials can begin. We will start with healthy volunteers and then continue with patients. Mowbray acknowledges that this will take a long time. ‘I imagine it will be at least five years before we have amassed enough data to ensure that these drugs are safe, affordable and readily available.’