Neglected Diseases
Mycetoma is a chronic infection of the skin and soft tissue caused by either flesh-eating fungi (eumycetoma) or bacteria (actinomycetoma). When left untreated, it can affect deeper tissues and lead to amputation.
Although the true global incidence and prevalence of mycetoma is still not fully known, it most often occurs across the so-called mycetoma belt, which includes Sudan, Chad, Ethiopia, Senegal, Somalia, Yemen, Mauritania, Venezuela, Mexico and India.
The current standard treatment for mycetoma has a cure rate of around 30% and comes with serious side effects. More effective, less toxic drugs with shorter duration of treatment are urgently needed. Aside from fosravuconazole, mycetoma drug R&D efforts are at a very early stage, such as DNDi’s MycetOs, a screening project to identify new leads, and niclosamide, a repurposed drug which showed potential in in-vitro studies. At present, mycetoma is diagnosed clinically, with identification of causative agents via histology and culture, techniques which require laboratory infrastructure and skilled practitioners. Specific diagnostics, such as PCR-based tests, are available only for research purposes. In 2022, the WHO published a target product profile (TPP) for a rapid test for diagnosis of mycetoma at the primary healthcare level. The TPP aims to facilitate the development of point-of-care tests that diagnose mycetoma and differentiate actinomycetoma and eumycetoma to allow initiation of appropriate treatments.
The majority of in-scope mycetoma product development – which covers only diagnostics and drugs – remains in the early stages of development. Eisai, in partnership with DNDi and the University of Khartoum, has recently completed Phase II trials comparing fosravuconazole and itraconazole for eumycetoma treatment. Fosravuconazole demonstrated high cure rates, good tolerance, and a convenient weekly dosing regimen, setting it apart from current treatments. In light of this, the GHIT Fund provided DNDi with €2 million in 2023 to aid fosravuconazole registration and preparatory efforts for patient access in Sudan and is also supporting the current Phase IIb/III study. Two other promising compounds, a fenarimol analog and niclosamide, are being investigated for potential alternative mycetoma therapies based on encouraging preclinical results.