Thyroxine Treatment in Premature Infants With Intraventricular Hemorrhage: Phase III Clinical Trial

Intraventricular hemorrhage (IVH) remains a major complication of prematurely born infants. Survivors of IVH suffer from cerebral palsy, cognitive deficits and neurobehavioral disorders. In the proposed study We hypothesize that T4 treatment in preterm (230/7-276/7 weeks) infants with grade II-IV IVH will: a) improve MRI biomarkers, including total myelinated white matter volume, Kidokoro scoring, functional connectivity between motor brain regions, and fractional anisotropy in the corpus callosum of preterm infants with grade II-IV IVH at 36 weeks postmenstrual age, and b) better composite outcome of disability and death. The composite outcome will be derived by integrating scores for Bayley Scales of Infant and Toddler Development (BSID-IV) Motor subscale at 22-26 months in survivors and BSID IV value of 46 assigned to deceased infants. To test these hypotheses, we will perform a randomized double-blinded placebo-controlled trial to determine the effect of T4 treatment on preterm infants with grade II-IV IVH. Ten participating neonatal intensive care units will enroll 346 premature infants (230/7-276/7 weeks gestational age. 173 in each arm) with unilateral or bilateral grade II-IV IVH over a period of 3 years. The treatment will consist of T4 administration (8 µg/kg/day divided into two doses) up to 34 weeks of postmenstrual age, which will be initiated at 2-5 days of postnatal age in all cases. The infants will undergo MRI with DTI at 36 weeks and neurobehavioral evaluation at 22-26 months of corrected age. We have assumed a 7.5 point mean difference (SD=15) in BSID-IV motor subscale between T4 and placebo groups, an overall mortality rate of 25%, and 5% reduction in mortality for each SD change in outcome. Based on these, we expect an increase in the induced composite outcome by ≥5.6 points in T4 treated group compared to placebo controls. The study will conclusively determine whether the proposed clinical trial of T4 treatment enhances motor outcome and diminishes composite endpoint of death or disability in preterm infants with grade II-IV IVH.