Ruxolitinib for Early Lung Dysfunction After Hematopoietic Stem Cell Transplant

Hematopoietic stem cell transplant (HSCT) is an effective but toxic therapy, and lung injury affects as many as 25% of children receiving HSCT. Improved transplant techniques and major improvements in survival mean that HSCT is being more widely used, and more mismatched grafts are being used. Bronchiolitis obliterans (BO) is a major limitation of pediatric HSCT success as BO is commonly diagnosed late in children, when lung injury is irreversible, leading to long term morbidity or even death. Currently, there are major gaps in our knowledge regarding incidence, etiology and optimal treatment of BO following HSCT, and important diagnostic limitations specific to children. Diagnosis of BO is usually based on performance of pulmonary function tests, which is usually impossible in ill children under 10. Even older children who feel unwell or un-cooperative may be unable to produce interpretable data. These deficiencies in diagnosis mean that BO is commonly diagnosed late, meaning fibrosis has occurred and lesions are irreversible. The hypothesis for this interventional trial is that early treatment with standard Flovent/montelukast and steroids plus ruxolitinib will reverse lung injury and reduce the frequency of chronic pulmonary impairment or florid BO.