Reduction in Lipoprotein(a) With PCSK9 Monoclonal Antibody Evolocumab (AMG 145)

Objectives The purpose of this study was assess the effect of evolocumab (AMG 145) on lipoprotein (Lp)(a) from a pooled analysis of 4 phase II trials. Background Lp(a), a low-density lipoprotein (LDL) particle linked to the plasminogen-like glycoprotein apolipoprotein(a), shows a consistent and independent positive association with cardiovascular disease risk in epidemiological studies. Current therapeutic options to reduce Lp(a) are limited. Methods A pooled analysis of data from 1,359 patients in 4 phase II trials assessed the effects of evolocumab, a fully human monoclonal antibody to PCSK9, on Lp(a), the relationship between Lp(a) and lowering of low-density lipoprotein cholesterol (LDL-C) and apolipoprotein B, and the influence of background statin therapy. Lp(a) was measured using a standardized isoform-independent method. Results Evolocumab treatment for 12 weeks resulted in significant (p < 0.001) mean (95% confidence interval) dose-related reductions in Lp(a) compared to control: 29.5% (23.3% to 35.7%) and 24.5% (20.4% to 28.7%) with 140 mg and 420 mg, dosed every 2 and 4 weeks, respectively, with no plateau of effect. Lp(a) reductions were significantly correlated with percentages of reductions in LDL-C (Spearman correlation coefficient, 0.5134; p < 0.001) and apolipoprotein B (Spearman correlation coefficient, 0.5203; p < 0.001). Mean percentage reductions did not differ based on age or sex but the trend was greater in those patients taking statins. Conclusions Inhibition of PCSK9 with evolocumab resulted in significant dose- related reductions in Lp(a). While the mean percentage of reduction was significantly greater in those patients with baseline Lp(a) of >= 125 nmol/l, the absolute reduction was substantially larger in those with levels >125 nmol/l. (C) 2014 by the American College of Cardiology Foundation