Single-dose Prophylactic INdomethacin in Extremely Preterm Infants

BACKGROUND \& IMPORTANCE In Canada, about 900 infants are born extremely preterm at \<26 weeks of gestation (GA); nearly four out of 10 of them do not survive or develop severe intraventricular hemorrhage (sIVH). Existing evidence shows that a 3-dose regimen of prophylactic intravenous indomethacin (0.1mg/kg/dose every 24h for 3 doses most commonly used clinically) results in a significant reduction in sIVH, an outcome deemed critical by families. However, use of the conventional 3-dose regimen has declined among clinicians due to perceived adverse effects on the gut, presumed lack of long-term neurodevelopmental benefit and preclusion of other early therapeutic interventions such as ibuprofen or hydrocortisone due to potential increased risk of gut perforation with concomitant use with indomethacin. Recent pharmacokinetic studies show that indomethacin drug clearance is significantly reduced in infants born ≤26 weeks GA in the first week of life due to their developmental immaturity; and consequently a single 0.1 mg/kg dose likely maintains therapeutic levels for at least 72h - the most critical period of sIVH onset in these smallest infants. However, no RCTs have yet been conducted to establish effectiveness and safety of this single dose regimen in this highest risk population. GOAL(S) / RESEARCH AIMS Primary goal: To determine the effectiveness and safety of single dose prophylactic indomethacin to prevent morbidity and mortality in extremely preterm infants born \<26 weeks GA. The investigators hypothesize that in preterm infants born \<26 weeks GA, when compared to placebo, a single 0.1 mg/kg dose of intravenous indomethacin given prophylactically within the first 12 hours of birth will improve survival without sIVH. METHODS/APPROACHES/EXPERTISE Study design: Multicenter, blinded, placebo-controlled, individually randomized, Bayesian design RCT Population: Preterm infants born \<26 weeks GA and/or \<750 g birth weight Intervention: Prophylactic indomethacin: Single-dose intravenous indomethacin (0.1 mg/kg) given within 12 hours of birth. Comparison: Equal volume saline placebo. Sample size and analysis: The proposed sample size is 500 neonates (250 per arm). The primary analysis will utilize a Bayesian approach using an informative prior that assumes a 5% expected net benefit (in absolute risk difference) with an uncertainty of 5%, with regards to the primary outcome. The trial will be considered successful if it shows that the posterior probability of a positive net benefit is at least 90%. Setting: Neonatal intensive care units across Canada, the United States and Australia over 3 years. The study will be conducted in 2 phases: (i) an internal pilot phase that will enroll 104 infants born \<26 weeks or \<750 g birth weight over a period of 1 year; (ii) If the investigators are successful in achieving their target enrolment in the pilot phase, they will move on to the second phase and continue enrollment up to a total of 500 infants born \<26 weeks or \<750 g birth weight over a period of 3 years. The total of 500 infants will include the 104 infants enrolled in the first phase of the study. Primary outcome: Survival without sIVH (grades 3 and 4) at hospital discharge Secondary outcomes include in-hospital clinical outcomes; white matter injury on MRI at term corrected age; neurodevelopmental impairment at 24 (±6) months; pharmacokinetic (PK) profile of single-dose indomethacin; total hospital costs and costs per sIVH or death averted. EXPECTED OUTCOMES This will be the first RCT to explore the effectiveness and safety of single dose prophylactic indomethacin exclusively in infants born \<26 weeks GA who are at the highest risk of severe IVH and death. Apart from the primary and secondary clinical outcomes, this trial will describe the PK profile of single dose indomethacin to establish the ideal therapeutic window for sIVH prevention as well as ascertain the value for money of this therapy in preventing death and sIVH in infants born \<26 weeks GA.