A total of 393 patients affected by different foms of hyperlipoproteinemia have been treated for up to 12 months or more with a daily dose of 200-400 mg of isopropyl-4'-(p-chlorobenzoyl)-2-phenoxy-2-methyl]-propionate (LF 178; procetofene; Lipanthyl). In pure hypercholesterolemia (IIa) the mean