Abstract 1696: Compound RVX-208 Modulates HDL-C Levels and Function in Non-human Primates and in Early (phase I) Human Trials
The novel compound RVX-208 is a small molecule that upregulates the gene expression of apoA-I and raises HDL-C in non-human primates. Here, we examined the effects of oral administration of RVX-208 on serum apoA-I and HDL-C levels , HDL size distribution, and HDL function. African green monkeys received RVX-208 (7.5, 15 and 30 mg/kg; twice daily and 60 mg/kg; once daily) or vehicle control for 28, 42, and 63 days. We report that RVX-208 chronic treatment resulted in a highly significant increase in the average of serum apoA-I and HDL-C levels (57% and 92%, respectively). Interestingly, RVX-208 treatment modified the distribution of HDL particle size causing a significant increase in preβ1-LpA-I and larger α1-LpA-I species. The ability of serum to promote cholesterol efflux via ABCA1, ABCG1 or SR-BI-dependent pathways in a cell culture model was significantly increased by RVX-208. The phase Ia safety and pharmacokinetic human study comprised of a total of 80 subjects. In the multiple ascending dose arm, 24 participants were randomly assigned to 3 cohorts of 8 healthy volunteers (6 active and 2 placebo), and received oral administration of RVX-208 at 2, 3 and 8 mg/kg per day or placebo for 7 days. The compound was well tolerated and had good oral absorption meeting the objectives of safety and pharmacokinetics. ApoA-I, HDL-C, HDL size distribution and ABCA1-dependent cholesterol efflux were assessed at days 1 (predose) and 7. The percent change from baseline to day 7 for apoA-I was 11% higher (P = 0.03) in the RVX-208 treated participants compared to placebo. Interestingly, preβ1-LpA-I change was 30% (P = 0.02) higher in the actively treated group and was found to strongly correlate with increased apoA-I levels (R2 = 0.72). Furthermore, ABCA1-dependent cholesterol efflux change was 10% higher (P = 0.03) and was found to correlate with increased preβ1-LpA-I . Taken together, these pharmacodynamic data from human healthy volunteers show consistent trends in apoA-I production and HDL functionality, supporting the findings in the African green monkey. Further investigation of the effect of RVX-208 on the HDL metabolic pathway is ongoing in humans and animals to establish the mechanisms of action and therapeutic potential in treating atherosclerotic cardiovascular disease.