Discovery Laboratories Inc. has announced encouraging results from the AEROSURF Phase IIa clinical program in premature infants 29 to 34 weeks gestational age, or GA, with respiratory distress syndrome, or RDS. The AEROSURF Phase IIa clinical program in premature infants 29 to 34 weeks GA consisted of two multicenter, randomized, open-label, controlled studies in a total of 80 premature infants receiving nasal continuous positive airway pressure (nCPAP) for RDS. The studies were designed to evaluate the safety and tolerability of aerosolized KL4 surfactant administered in five dose groups (15, 30, 45, 60 and 90 minutes), compared to infants receiving nCPAP alone.

All key objectives of the program were achieved. Overall, the safety and tolerability profile of the AEROSURF group in this Phase IIa program was generally comparable to the control group; and data suggest that AEROSURF may be reducing the incidence of nCPAP failure, which occurs when premature infants initially treated with nCPAP alone, require delayed surfactant therapy by means of invasive endotracheal intubation. Through 72 hours after the start of AEROSURF treatment, the AEROSURF-treated patients, predominantly receiving a single dose, had lower rates of nCPAP failure compared to control in each of the last three dose groups studied.

nCPAP failure rates were 53% in the control group compared to 38%, 14% (excluding one patient who was inappropriately enrolled) and 38% in the 45, 60 and 90 minute AEROSURF dose groups, respectively. The Company has focused its planning for the Phase IIb clinical trial on the 45 and 60 minute dose groups. The combined data for these groups indicate that, through 72 hours after the start of AEROSURF treatment, AEROSURF-treated patients had a 27% nCPAP failure rate compared to 53% in the control group.

This represents a 26% absolute reduction or a 49% relative reduction in nCPAP failure compared to control. Premature infants with RDS are born with immature lungs and may require surfactant therapy to sustain them in the first hours of life and for up to 48 to 72 hours. Currently in the US surfactant therapy is administered through endotracheal intubation.