Human Amnion Epithelial Cells for Prevention of Bronchopulmonary Dysplasia in Preterm Infants: A Safety Study

Owing to advances in neonatal care, survival of preterm infants, particularly those born at less than or equal to 28 weeks, is increasing. Survival brings with it the risk of morbidity. Bronchopulmonary dysplasia (BPD), lung disease unique to preterm infants, is an important morbidity associated with long term impairments of lung function and neurodevelopment. Despite advances in the care of preterm infants, rates of BPD in survivors have not changed over recent decades. In fact, pulmonary outcomes in recent cohorts of preterm infants appear worse. With developments in neonatal medicine over the last few decades the phenotype of BPD has changed. Today, infants at greatest risk of BPD are born in the canalicular phase of lung development, a time when alveolar and distal capillary development commences. Preterm delivery and the interventions compromising neonatal intensive care create a proinflammatory environment disrupting the architecture of vulnerable developing lungs. Targeting inflammation with new generation therapies may provide new therapeutic options for BPD. Preclinical models have demonstrated human amnion epithelial cells (hAECs) can prevent and repair lung injury by modifying the inflammatory response, helping to restore normal lung architecture. hAECs have potential to reduce the incidence and/or severity of BPD. A small phase 1 study completed at Monash Health in Melbourne, Australia gave 1 million hAECs/kg to infants with established BPD. This was a first-in-human study and appropriately gave a conservative dose of hAECs to assess safety. Prior to larger trials to study the efficacy of hAECs as a preventive therapy for BPD, tolerance to higher doses of hAECs, which are more likely to be efficacious based on preclinical studies, must be established in a younger, less mature population of preterm infants. Accordingly, we propose a multicentre dose escalation trial to assess the safety of intravenously administered hAECs in preterm infants at high risk of developing BPD. Infants will be assessed as being at high risk of BPD if delivered at less than 29 weeks gestational age and on Day 14 of life require either mechanical ventilation with an FiO2 greater than or equal to 0.25 or non-invasive respiratory support with an FiO2 greater than or equal to 0.35. 24 infants will be recruited and given intravenous hAECs during the third and fourth week of life at doses increasing from 2 million hAECs/kg to 30 million hAECs/kg. The first 12 infants will receive a single infusion to a maximum dose of 10 million hAECs/kg. Larger total doses will be achieved in the final 12 patients by repeat infusions at 5 day intervals. Safety is the primary outcome and will be defined by the occurrence of adverse events during the 2 year follow-up period. Secondary outcomes include cytokine profiling and neonatal morbidities, in particular the incidence and severity of BPD.