 Recombinant human CC10 protein rhCC10 is a novel therapeutic agent used to prevent the development of chronic respiratory morbidity CRM; repeated respiratory infections, asthma, re-hospitalizations in preterm infants. Native CC10 is a natural anti-inflammatory and immunomodulatory factor produced by Clara Cells in the lung and is the most abundant protein in respiratory mucosa. Animal data demonstrate that a single intratracheal dose of rhCC10 administered shortly after birth reduces lung inflammation important biomarkers linked to lung injury in preterm infants, promotes normal lung development, preserves lung architecture, improves pulmonary function, suppresses the response to endotoxin and enhances resistance to pulmonary infections. In preterm infants who die or develop lung inflammation and subsequent bronchopulmonary dysplasia BPD, both the concentration and activity of CC10 are significantly reduced indicating that CC10 is essential for preventing lung injury and promoting normal lung development. In a small phase I study, rhCC10 significantly decreased several indices of pulmonary inflammation in the lungs of premature infants who were at risk of developing BPD and associated CRM. The drug appeared to be safe, well-tolerated, and reduce risk of re-hospitalization due to respiratory illness for 9-10 months after a single intratracheal dose at the time of birth 011 rhCC10-treated infants vs. 36 placebo-treated. This supports the protective role of rhCC10 against damage from hyperoxia, mechanical ventilation, inflammation, and infection in the immature lung. A more normal airway epithelium will produce significantly more endogenous CC10, with both factors contributing to enhanced resistance to infections, less asthma, and improved long-term respiratory outcome. We propose to conduct a Phase 2 clinical trial to evaluate rhCC10 in extremely premature infants 29 weeks gestation for the prevention of BPD and CRM. This will be a randomized, double-blind, placebo-controlled dose escalation study in 88 premature infants. A single intratracheal dose of study drug rhCC10 or placebo will be administered to preterm infants receiving surfactant and mechanical ventilation for treatment of RDS. Infants will be followed to evaluate safety, pharmacokinetics, and short and long term efficacy of this approach. Safety will be evaluated through serious adverse event SAE and adverse event monitoring and by Bayley neurodevelopmental assessments at 18 months corrected gestational age CGA. Efficacy measurements will include the primary combined endpoint of alive without evidence of CRM through 12 months CGA defined by parental diaries and pulmonary questionnaires comparing rhCC10 treated to placebo controls. The availability of a therapy which prevents lung injury, promotes lung development, and prevents serious respiratory infections and asthma in high risk preterm infants would be a highly significant advancement in care. 