Treatment for human visceral leishmaniasis: a cost-effectiveness analysis for Brazil

Economic evaluations addressing diagnosis and treatment strategies for neglected tropical diseases: an overview

Neglected tropical diseases (NTDs) are those affecting vulnerable people and causing additional social and economic burden. The aim of this study was to carry out a general overview of the health economic assessments involving the diagnosis and treatment of six NTDs: cutaneous leishmaniasis (CL), Chagas disease, cysticercosis, filariasis, schistosomiasis and visceral leishmaniasis (VL). The literature search was based on two of the main medical literature databases (Medline and SciELO) and identified 46 studies. Twenty-six studies (57%) addressed therapeutic strategies, while other 20 (43%) assessed diagnostic or both diagnostic and therapeutic approaches. The studies were published between 1994 and 2021, and 57% of them (26/46) were carried out in four countries. Cost-effectiveness analyses were conducted in 59% (27/46) of the studies. Economic studies of NTDs have timidly increased in recent years. Despite the improvement of analytical methods, completeness and accuracy of information, there are few new technologies applied to NTDs and public health systems. In addition, economic studies for NTDs are concentrated in a few countries. Thus, this review points out the need for investment in research, development and training of human resources dedicated to the economic analysis in health, especially on NTDs, as a strategy to reduce inequalities by optimizing the use of health resources.

Effect of Itraconazole-Ezetimibe-Miltefosine Ternary Therapy in Murine Visceral Leishmaniasis

Drug combination therapy is an interesting approach to increase the success of drug repurposing for neglected diseases. Thus, the objective of this work was to evaluate binary and ternary therapies composed of itraconazole, ezetimibe and miltefosine for the treatment of visceral leishmaniasis. Intracellular Leishmania infantum amastigotes were incubated with the drugs alone or in combination for 72 h. For in vivo experiments, we tested a long-course (21 days, once per day) and a short-course treatment (5 days, twice per day) for the binary combination with itraconazole and ezetimibe. For the ternary therapy including miltefosine, we adopted the short-course treatment and varied the vehicle. None of the combinations were toxic to macrophages. Binary combination of itraconazole plus ezetimibe and ternary combination of itraconazole, ezetimibe and miltefosine had synergistic effects in intracellular amastigotes, in some of the proportions evaluated. Although the in vivo long-course therapy had been more effective than the short-course protocol, it showed hepatic toxicity signs. Ezetimibe has proven to be able to reduce the parasite burden alone or in combination. Both suspensions of the ternary combination were active, but when the drugs were suspended in the commercial ORA-Plus formulation instead of purified water, the parasite burden was reduced by 98% in the liver and spleen. Altogether, the results demonstrate for the first time the activity of ezetimibe in a viscerotropic species of Leishmania and indicate that ternary treatment composed of miltefosine, itraconazole, and ezetimibe at low doses is a promising therapeutic alternative for the treatment of visceral leishmaniasis.

Treatment With Liposomal Amphotericin B for All Confirmed Cases of Human Visceral Leishmaniasis in Brazil: A Budget Impact Analysis

OBJECTIVES

To estimate the budget impact of the expansion of liposomal amphotericin B use for all confirmed cases of visceral leishmaniasis (VL) in Brazil. Currently, the first-line medicine for VL treatment is meglumine antimoniate. Liposomal amphotericin B is indicated only for patients with a greater risk of severity by the disease.

METHODS

The analysis was performed from the perspective of the Brazilian public healthcare system over 3 years, considering the following 2 scenarios: the reference scenario with the current recommendations for VL treatment and the alternative scenario based on the use of liposomal amphotericin B for all patients. A diffusion rate of 60% was used in the first year, 80% in the second year, and 100% in the third year. The epidemiological parameters used in the analysis came from the Notifiable Diseases Information System and from a clinical trial that evaluated the efficacy and safety of medicines for the treatment of VL in the country. The costs were related to the treatment of VL and to hospital and outpatient care.

RESULTS

In the reference scenario, the total cost for treatment of the 3453 VL confirmed cases in 2014 was $1 447 611.75. The incremental budget impact with the use of liposomal amphotericin B for all the VL confirmed cases was $299 646.43 in the third year.

CONCLUSIONS

The analysis presented will support the decision process for the use and expansion of liposomal amphotericin B for all VL confirmed cases in Brazil.

Preclinical Gold Complexes as Oral Drug Candidates to Treat Leishmaniasis Are Potent Trypanothione Reductase Inhibitors

The drugs currently used to treat leishmaniases have limitations concerning cost, efficacy, and safety, making the search for new therapeutic approaches urgent. We found that the gold(I)-derived complexes were active against L. infantum and L. braziliensis intracellular amastigotes with IC₅₀ values ranging from 0.5 to 5.5 μM. All gold(I) complexes were potent inhibitors of trypanothione reductase (TR), with enzyme IC₅₀ values ranging from 1 to 7.8 μM. Triethylphosphine-derived complexes enhanced reactive oxygen species (ROS) production and decreased mitochondrial respiration after 2 h of exposure, indicating that gold(I) complexes cause oxidative stress by direct ROS production, by causing mitochondrial damage or by impairing TR activity and thus accumulating ROS. There was no cross-resistance to antimony; in fact, SbR (antimony-resistant mutants) strains were hypersensitive to some of the complexes. BALB/c mice infected with luciferase-expressing L. braziliensis or L. amazonensis and treated orally with 12.5 mg/kg/day of AdT Et (3) or AdO Et (4) presented reduced lesion size and parasite burden, as revealed by bioimaging. The combination of (3) and miltefosine allowed for a 50% reduction in miltefosine treatment time. Complexes 3 and 4 presented favorable pharmacokinetic and toxicity profiles that encourage further drug development studies. Gold(I) complexes are promising antileishmanial agents, with a potential for therapeutic use, including in leishmaniasis caused by antimony-resistant parasites.