Résumé
Background: in 2018, the US FDA approved 8 mg moxidectin (MOX) for onchocerciasis in individuals aged ≥12 years. Moxidectin’s safety in L. loa infected individuals has never been evaluated. Severe adverse reactions as observed after ivermectin (IVM) may occur in individuals with high L. loa microfilaria density (MFD). This study compared the safety and parasitological efficacy of a 2 mg MOX and the standard 150 µg/kg IVM dose in individuals with low L loa MFD.Methods: a double-blind randomized, ivermectin-controlled trial of a 2 mg moxidectin dose in Cameroon (May-July 2022) enrolled adult men with L. loa MFD between 5–1000 mf/mL by ascending MFD. Outcomes were occurrence of adverse events (AE) during the first week and month and L. loa MFD reduction rate during the first month post-treatment. Findings: no serious or severe AEs occurred among the 36 MOX or the 36 IVM treated individuals. Forty-nine AEs occurred in the MOX arm vs 59 AEs in the IVM arm. Grade 2 AE incidence was higher among IVM than MOX treated participants (38·5% and 14·3%, respectively, p=0·043). Median MFD reduction rates were significantly higher after IVM than MOX administration at day 3 (D3) (70·2% vs 48·5%), D7 (76·4% vs 50·0%) and D30 (79·8% vs 48·1%). Interpretation: a single 2 mg MOX dose seems safer than 150 µg/kg IVM in patients with low L. loa MFD. Further studies with higher moxidectin doses and in patients with higher MFD are warranted.