ALC-0159 is a PEG/lipid conjugate (i.e. PEGylated lipid), specifically, it is the N,N-dimyristyl amide of 2-hydroxyacetic acid, O-pegylated to a PEG chain mass of about 2 kilodaltons (corresponding to about 45-46 ethylene oxide units per molecule of N,N-dimyristyl hydroxyacetamide).
The compounds of every Wikipedia article carrying a Chembox or a Drugbox, refreshed daily, with the values their infoboxes give. The pages need JavaScript; the API does not.