Prospective evaluation of hydroxychloroquine in pediatric interstitial lung diseases: Study protocol for an investigator-initiated, randomized controlled, parallel-group clinical trial

Background Interstitial lung diseases in children (chILD) are rare and consist of many different entities that affect the parenchyma of the lungs, leading to a chronic lung disease. The natural course of many of these diseases is connected with a high morbidity and significant mortality. Symptomatic treatment consists of oxygen supplementation, adequate nutrition adapted to the high energy demand generated by the disease due to the increased breathing effort required, as well as immunization against respiratory pathogens to prevent exacerbations through respiratory infections. No proven pharmacological treatments are available to date. This placebo-controlled study aims to evaluate the efficacy and safety of the mid-term use of hydroxychloroquine in chILD. Methods and design The study is an explorative, prospective, randomized, double-blind, placebo-controlled investigation of hydroxychloroquine (HCQ) in chILD. Patients can be included into the trial when diagnosed with a chronic (>= 3 weeks' duration) diffuse parenchymal lung disease (chILD) (1) genetically defined, (2) histologically defined or (3) diagnosed with idiopathic pulmonary hemorrhage (hemosiderosis). The study contains of two different study blocks, a START and a STOP block, which can be initiated in any sequence. Each patient can participate in each block only once. In the START block subjects are randomized to parallel groups for 4 weeks treatment, then the placebo group is switched to the active drug. In the STOP block, subjects taking HCQ are randomized into parallel groups treated with placebo or HCQ. Discussion This study is the first international, investigator-initiated, prospective and controlled investigation of a pharmacological treatment in chILD. The block design was selected as it has the advantage of accommodating patients who are initiating or withdrawing from HCQ therapy, thus allowing the participation of those who were previously started on off-label HCQ. The cross-over design and selected outcome parameters enables us to include appropriate numbers of patients of all age groups from neonates to adults suffering from these rare diseases.