Treatment of Low HDL-C Subjects with the CETP Modulator Dalcetrapib Increases Plasma Campesterol Only in Those Without ABCA1 and/or ApoA1 Mutations.

We investigated the effect of dalcetrapib treatment on phytosterol levels in patients with familial combined hyperlipidemia (FCH) or familial hypoalphalipoproteinemia (FHA) due to mutations in apolipoprotein A1 ( ApoA1) or ATP-binding cassette transporter A1 ( ABCA1). Patients ( n = 40) with FCH or FHA received dalcetrapib 600 mg or placebo in this 4-week, double-blind, crossover study. Lipids, apolipoproteins, cholesteryl ester transfer protein (CETP) activity and mass, and phytosterols were assessed. Dalcetrapib increased high-density lipoprotein cholesterol (HDL-C) and ApoA1 levels to a similar extent in FHA (+22.8, +13.9 %) and FCH (+18.4, +12.1 %), both p < 0.001 vs. placebo. Changes in CETP activity and mass were comparable for FHA (−31.5, +120.9 %) and FCH (−26.6, +111.9 %), both p < 0.0001 vs. placebo. Campesterol and lathosterol were unchanged in FHA (+3.8, +3.0 %), but only campesterol was markedly increased in FCH (+25.0 %, p < 0.0001 vs. placebo). Campesterol increased with dalcetrapib treatment in FCH but not in FHA, despite comparable HDL-C and ApoA1 increases, suggesting that ApoA1 and/or ABCA1 is essential for HDL lipidation by enterocytes in humans. [ABSTRACT FROM AUTHOR]