Sinapultide

Sinapultide (also known as KL4 peptide) is a synthetic protein used to mimic human lung surfactant protein B.^L2502 This protein has a weight of 2469.40.^L2502

Sinapultide is a 21-residue peptide made up of lysine (K) and leucine (L) residues with the sequence KLLLLKLLLLKLLLLKLLLLK (KL4), in aqueous dispersion with the phospholipids DPPC (dipalmitoylphosphatidylcholine), POPG (palmitoyloleoyl-phosphatidylglycerol), and palmitic acid, to create the drug lucinactant.^L2506

The product was originally developed by the Scripps Research Institute, then licensed to Windtree Therapeutics.^L2502 Windtree Therapeutics plans a phase III trial for Respiratory distress syndrome in 2018.^L2505

Respiratory distress syndrome (RDS) is a major cause of mortality and morbidity in preterm infants. Surfactant replacement therapy has been commonly used to prevent and treat RDS in these newborns and is now a standard of care. First-generation synthetic surfactants that were previously used, such as Exosurf did not contain any surfactant protein. This large disadvantage was overcome with animal-derived surfactant products which contain specific proteins but are limited, but must be derived from animal sources. This has led to the development of newer synthetic surfactants such as lucinactant (Surfaxin), which contains sinapultide. Phase 3 clinical trials with Surfaxin show promising results with similar efficacy as animal-derived surfactants while avoiding the use of animal-origin products.^L2504

Windtree is currently developing aerosolized KL4 surfactant to treat RDS in premature infants, and thereafter, to potentially address a range of indications in neonatal, pediatric and adult critical care patient populations.^L2511