This will be a double-blind (neither physician nor participant knows the treatment that the participant receives), randomized (the study drug is assigned by chance), multi-center, parallel-group study (each group of participants will be treated at the same time) to evaluate the efficacy and safety of mebendazole (a drug currently being investigated for Helminth gastrointestinal infections) compared with placebo (an inactive substance that is compared with a drug to test whether the drug has a real effect in a clinical trial) in children (including pre-school and school-aged children) with Helminth infections. The study will consist of 3 phases: a screening phase, a double-blind treatment phase, and a post-treatment (or follow-up) phase. A pharmacokinetic (explores what a drug does to the body) open-label substudy (asks a separate research question from the parent study while using the same participant population but does not contribute to the parent study's objectives) will be included in the parent study to measure the level of mebendazole in the blood. Safety assessments will be performed throughout the study. Each participant will take part in the study for approximately 30 days.
The purpose of this study is to evaluate the efficacy and safety of mebendazole compared with placebo in pediatric participants with Helminth infections.