Ivermectin therapy for young children with scabies infection: a multicentre phase 2 non-randomized trial.

Abstract

<h4>Background</h4>Ivermectin, an effective treatment for scabies, is not licensed for children weighing <15 kg. Pharmacokinetic modelling has shown a 3 mg dose in young children (2-4 years, weighing 10-14 kg) achieves comparable drug exposure to a 200 μg/kg dose in children aged ≥5 years. This trial evaluated a 3 mg dose in young children.<h4>Methods</h4>Multicentre, phase 2 trial in five health centres in Lao PDR. Children aged 2-4 years, weighing 10-14 kg with scabies received 3 mg ivermectin and had two plasma concentrations determined (Clinicaltrials.gov ID NCT05500326). On day 14, clinical outcomes and adverse effects were assessed, and a second dose given to complete treatment. The primary outcome was the mean plasma ivermectin exposure (AUC_0-∞) after the first dose (compared to a historical control of Indigenous Australian children aged ≥5 years weighing ≥15 kg receiving 200 μg/kg). Secondary outcomes were clinical improvement and adverse effects.<h4>Findings</h4>Overall, 100 children with a median age of 3.0 years (IQR 2.6-3.9) and weight of 11.9 kg (IQR 11.0-13.1) were enrolled. The mean observed ivermectin AUC_0-∞ was comparable to the historical control group aged 5-11 years (815 μg h/L vs 953 μg h/L, p = 0.256). Complete resolution of scabies occurred in 90/99 children by day 14. Adverse effects were mild, occurring in 7/99.<h4>Interpretation</h4>A 3 mg ivermectin dose in children aged 2-4 years and weighing 10-14 kg achieved a mean plasma AUC_0-∞ comparable to older children, was highly effective in treating scabies and well tolerated. This study supports extending ivermectin treatment to younger children improving global efforts to control this neglected disease.<h4>Funding</h4>Project funding provided by a Thrasher Foundation Early Career Research Award.