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 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.