Reduction in Lipoprotein(a) With PCSK9 Monoclonal Antibody Evolocumab (AMG 145): A Pooled Analysis of More Than 1,300 Patients in 4 Phase II Trials

Abstract

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. 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. 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. 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. 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.