The potential impact of moxidectin on onchocerciasis elimination in Africa: an economic evaluation based on the Phase II clinical trial data.

Hugo C Turner,Martin Walker,Nicholas O Opoku,Simon K Attah,María-Gloria Basáñez,Annette C Kuesel,Kwablah Awadzi

doi:10.1186/s13071-015-0779-4

Abstract

BackgroundSpurred by success in several foci, onchocerciasis control policy in Africa has shifted from morbidity control to elimination of infection. Clinical trials have demonstrated that moxidectin is substantially more efficacious than ivermectin in effecting sustained reductions in skin microfilarial load and, therefore, may accelerate progress towards elimination. We compare the potential cost-effectiveness of annual moxidectin with annual and biannual ivermectin treatment.MethodsData from the first clinical study of moxidectin were used to parameterise the onchocerciasis transmission model EPIONCHO to investigate, for different epidemiological and programmatic scenarios in African savannah settings, the number of years and in-country costs necessary to reach the operational thresholds for cessation of treatment, comparing annual and biannual ivermectin with annual moxidectin treatment.ResultsAnnual moxidectin and biannual ivermectin treatment would achieve similar reductions in programme duration relative to annual ivermectin treatment. Unlike biannual ivermectin treatment, annual moxidectin treatment would not incur a considerable increase in programmatic costs and, therefore, would generate sizeable in-country cost savings (assuming the drug is donated). Furthermore, the impact of moxidectin, unlike ivermectin, was not substantively influenced by the timing of treatment relative to seasonal patterns of transmission.ConclusionsMoxidectin is a promising new drug for the control and elimination of onchocerciasis. It has high programmatic value particularly when resource limitation prevents a biannual treatment strategy, or optimal timing of treatment relative to peak transmission season is not feasible.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-015-0779-4) contains supplementary material, which is available to authorized users.

Highlights

Spurred by success in several foci, onchocerciasis control policy in Africa has shifted from morbidity control to elimination of infection
In the Phase II clinical trial, a single dose of 8 mg moxidectin reduced pre-treatment skin microfilarial levels by 98%-100% from 8 to 365 days after treatment (Figure 1B, [17]). This higher and more prolonged efficacy compared to ivermectin (Figure 1A) resulted in shorter simulated programme durations for annual community-directed treatment with moxidectin (aCDTM) than annual community-directed treatment with ivermectin (aCDTI)
This was found to apply both when aCDTM is used from the outset (Table 2, Figure 2) and when a switch from aCDTI to aCDTM is made during ongoing control activities (Figure 3, Additional file 1: Table S4)

Summary

Introduction

Spurred by success in several foci, onchocerciasis control policy in Africa has shifted from morbidity control to elimination of infection. In the 13 endemic foci in Latin America (population at risk approximately 0.56 million), biannual ivermectin mass treatment (complemented in certain hyperendemic areas with more frequent administration) has, or is likely to have, interrupted transmission in 11 foci [4,5]. Biannual CDTI (bCDTI) could improve the chances of achieving elimination in Africa, which has a population at risk of onchocerciasis of approximately 115 million people [6]. Ghana and Uganda currently implement bCDTI in selected foci [9,10], and bCDTI was used in several of the Special Intervention Zones after the closure of the former Onchocerciasis Control Programme in West Africa (OCP) [11]

Methods

Results

Discussion

Conclusion