Background: Visceral leishmaniasis (VL) is one of the most neglected parasitic diseases causing large scale mortality and morbidity among the poorest of the poor in the Indian subcontinent and Africa. Objective: This review aims to describe the potential and the (lack of) current impact of newly developed treatments on the control of VL. It describes how the problem of an empty research pipeline is addressed, and discusses the emerging threat of incurable HIV/VL coinfection. Methods: The literature was searched for drugs used in VL. Conclusion: Research and development of VL drugs has received a financial boost but no new drugs are expected in the next 5 years. Only three new and highly effective treatments have been licensed in the past 10 years. These remain, however, largely inaccessible as VL control programs in the developing world are lacking. This is deserving of immediate and urgent attention, especially in the context of the rapidly expanding HIV/VL coinfection.

Background Miltefosine (MF) is the only oral drug available for treatment of visceral leishmaniasis (VL) and post-kala-azar dermal leishmaniasis (PKDL). Although the drug is effective and well tolerated in treatment of VL, the efficacy and safety of MF for longer treatment durations (>28 days) in PKDL remains unclear. This study provides an overview of the current knowledge about safety and efficacy of long treatment courses with MF in PKDL, as a strategy in the VL elimination in South Asia. Methodology/Principal findings Literature was searched systematically for articles investigating MF treatment in PKDL. A meta-analysis included eight studies (total 324 PKDL patients) to estimate the efficacy of MF in longer treatment regimens (range 6–16 weeks). We found a per-protocol (PP) initial cure rate of 95.2% (95%CI 89.6–100.8) and a PP definite cure rate of 90% (95%CI 81.6–96.3). Descriptive analysis showed that 20% of patients experienced adverse events, which mostly had an onset in the first week of treatment and were likely to get more severe after four weeks of treatment. Gastrointestinal (GI) side effects such as vomiting, nausea, diarrhoea, and abdominal pain were most common. Conclusions/Significance Longer treatment regimens with MF are effective in PKDL patients in India, however with the caveat that the efficacy has recently been observed to decline. GI side effects are frequent, although mostly mild or moderate. However, on the basis of limited data, we cannot conclude that longer MF treatment regimens are safe. Moreover, VL and PKDL pharmacovigilance studies indicate a risk for serious adverse events, questioning the safety of MF. The provision of safer treatment regimens for PKDL patients are therefore recommended. Until these regimens are identified, it should be considered to halt the use of MF monotherapy for PKDL in order to preserve the drug’s efficacy.