BACKGROUND: Available therapeutic surfactants are either animal-derived or 
non-protein-containing synthetic products. Animal-derived surfactants contain 
variable amounts of surfactant apoproteins, whereas the older-generation 
synthetic products contain only phospholipids and lack surfactant proteins 
(SPs). Both decrease morbidity and mortality rates associated with respiratory 
distress syndrome (RDS) among preterm infants, compared with placebo. However, 
excess mortality rates have been observed with non-protein-containing synthetic 
surfactants, compared with the animal-derived products. Evidence suggests that 
synthetic surfactants consisting solely of phospholipids can be improved with 
the addition of peptides that are functional analogs of SPs. Lucinactant is a 
new synthetic peptide-containing surfactant that contains sinapultide, a novel, 
21-amino acid peptide (leucine and lysine repeating units, KL4 peptide) designed 
to mimic human SP-B. It is completely devoid of animal-derived components.
OBJECTIVE: We hypothesized that the outcomes for premature infants treated with 
lucinactant and poractant alfa would be similar. Therefore, we compared 
lucinactant (Surfaxin; Discovery Laboratories, Doylestown, PA) with 
porcine-derived, poractant alfa (Curosurf; Chiesi Farmaceutici, Parma, Italy) in 
a trial to test for noninferiority.
METHODS: A total of 252 infants born between 24 and 28 weeks of completed 
gestation, with birth weights between 600 and 1250 g, were assigned randomly in 
a multicenter, multinational, noninferiority, randomized, controlled study to 
receive either lucinactant (n = 124) or poractant alfa (n = 128) within 30 
minutes of life. The primary outcome was the incidence of being alive without 
bronchopulmonary dysplasia (BPD) through 28 days of age. Key secondary outcomes 
included death at day 28 and 36 weeks postmenstrual age (PMA), air leaks, 
neuroimaging abnormalities, and other complications related to either 
prematurity or RDS. An independent, international, data and safety monitoring 
committee monitored the trial.
RESULTS: The treatment difference between lucinactant and poractant alfa for 
survival without BPD through 28 days was 4.75% (95% confidence interval [CI]: 
-7.3% to 16.8%) in favor of lucinactant, with the lower boundary of the 95% CI 
for the difference, ie, -7.3%, being greater than the prespecified 
noninferiority margin of -14.5%. At 28 days, 45 of 119 infants given lucinactant 
were alive without BPD (37.8%; 95% CI: 29.1-46.5%), compared with 41 of 124 
given poractant alfa (33.1%; 95% CI: 24.8-41.3%); at 36 weeks PMA, the rates 
were 64.7% and 66.9%, respectively. The corresponding mortality rate through day 
28 for the lucinactant group was lower than that for the poractant alfa group 
(11.8% [95% CI: 6.0-17.6%] vs 16.1% [95% CI: 9.7-22.6%]), as was the rate at 36 
weeks PMA (16% and 18.5%, respectively). There were no differences in major 
dosing complications. In addition, no significant differences were observed in 
the incidences of common complications of prematurity, including 
intraventricular hemorrhage (grades 3 and 4) and cystic periventricular 
leukomalacia (lucinactant: 14.3%; poractant alfa: 16.9%).
CONCLUSIONS: Lucinactant and poractant alfa were similar in terms of efficacy 
and safety when used for the prevention and treatment of RDS among preterm 
infants. The ability to enhance the performance of a synthetic surfactant with 
the addition of a peptide that mimics the action of SP-B, such as sinapultide, 
brings potential advantages to exogenous surfactant therapy.