Question: Which enzyme is targeted by Evolocumab?

Context:
Efficacy and safety profile of evolocumab (AMG145), an injectable inhibitor of the proprotein convertase subtilisin/kexin type 9: the available clinical evidence.
AREAS COVERED: Evolocumab (AMG145) is a monoclonal antibody inhibiting the proprotein convertase subtilisin/kexin type 9 that binds to the liver LDL receptor and prevents it from normal recycling by targeting it for degradation. 
Efficacy and safety of evolocumab (AMG 145), a fully human monoclonal antibody to PCSK9, in hyperlipidaemic patients on various background lipid therapies: pooled analysis of 1359 patients in four phase 2 trials.
We report a pooled analysis from four phase 2 studies of evolocumab (AMG 145), a monoclonal antibody to PCSK9. 
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.
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.
CONCLUSIONS: Inhibition of PCSK9 with evolocumab resulted in significant dose-related reductions in Lp(a). 
Monoclonal antibodies that inhibit proprotein convertase subtilisin/kexin type 9, including evolocumab (previously AMG 145), dramatically lowered LDL-C in phase 2 clinical trials when administered alone or in combination with a statin. 
Evolocumab (AMG 145) is a fully human monoclonal antibody that binds PCSK9, inhibiting its interaction with the LDL receptor to preserve LDL-receptor recycling and reduce LDL-C.
Antibody therapeutics in Phase 3 studies are described, with an emphasis on those with study completion dates in 2014, including antibodies targeting interleukin-17a or the interleukin-17a receptor (secukinumab, ixekizumab, brodalumab), proprotein convertase subtilisin/kexin type 9 (alirocumab, evolocumab, bococizumab), and programmed death 1 receptor (lambrolizumab, nivolumab).
BACKGROUND: Evolocumab (AMG 145), a monoclonal antibody against proprotein convertase subtilisin/kexin type 9 (PCSK9), significantly reduced low-density lipoprotein cholesterol (LDL-C) in phase 2 studies of 12 weeks' duration. 
These compounds act either by reducing low-density lipoprotein (LDL) production by inhibiting apolipoprotein B synthesis with an antisense oligonucleotide (mipomersen) or by inhibiting microsomal triglyceride transfer protein (lomitapide), or by enhancing LDL catabolism via monoclonal antibody-mediated inhibition of the activity of proprotein convertase subtilisin/kexin 9 (PCSK9) (evolocumab). 
Inhibition of PCSK9 with evolocumab in homozygous familial hypercholesterolaemia (TESLA Part B): a randomised, double-blind, placebo-controlled trial.
Evolocumab, a monoclonal antibody to proprotein convertase subtilisin/kexin type 9 (PCSK9), reduced LDL cholesterol by 16% in a pilot study. 
PCSK9 inhibition with evolocumab (AMG 145) in heterozygous familial hypercholesterolaemia (RUTHERFORD-2): a randomised, double-blind, placebo-controlled trial.
We investigated the effect of PCSK9 inhibition with evolocumab (AMG 145) on LDL cholesterol in patients with this disorder. 
Some of the anti-dyslipidemic drugs which work by PCSK9 inhibition include evolocumab, alirocumab and ALN-PCS.
We highlight the different steps of this adventure and review the published clinical trials especially those with the anti-PCSK9 antibodies evolocumab (AMG 145) and alirocumab (SAR236553/REGN727), which are in phase III trials.
Monoclonal antibodies against PCSK9 represent so far the most advanced approach in clinical development, with alirocumab, evolocumab and bococizumab under advanced clinical development. 
AREAS COVERED: Evolocumab and alirocumab are fully human monoclonal antibodies inhibiting the proprotein convertase subtilisin/kexin type 9 (PCSK9) that binds to hepatic LDL receptor and prevents it from normal recycling by targeting it for degradation.
Phase II (for evolocumab and alirocumab) and III (for evolocumab) trials show that PCSK9 inhibitors are equally well tolerated, with adverse events mainly limited to mild-to-moderate nasopharyngitis, injection-site pain, arthralgia and back pain. 
Four classes of newer lipid-lowering drugs offer promising advances in treating FH, namely the apolipoprotein-B synthesis inhibitors (mipomersen), the microsomal transfer protein inhibitors (lomitapide), the cholesterol ester transfer protein inhibitors (anacetrapib, evacetrapib) and the proprotein convertase subtilisin/kexin type 9 inhibitors (evolocumab, alirocumab).
Monoclonal antibodies that inhibit proprotein convertase subtilisin/ kexin type 9 (PCSK9), which degrades the LDL receptor, like alirocumab and evolocumab, are in phase 3 trials.
In support of the drug development program for Evolocumab, a fully human IgG₂ antibody that targets PCSK9, a quantitative ELISA to measure free PCSK9 in human serum was developed. 
IMPORTANCE: In phase 2 studies, evolocumab, a fully human monoclonal antibody to PCSK9, reduced LDL-C levels in patients receiving statin therapy. 
Anti-PCSK9 antibody effectively lowers cholesterol in patients with statin intolerance: the GAUSS-2 randomized, placebo-controlled phase 3 clinical trial of evolocumab.
Evolocumab, a fully human monoclonal antibody to proprotein convertase subtilisin/kexin type 9 (PCSK9), demonstrated marked reductions in plasma low-density lipoprotein cholesterol (LDL-C) in a phase 2 study in statin-intolerant patients.
Anti-PCSK9 monotherapy for hypercholesterolemia: the MENDEL-2 randomized, controlled phase III clinical trial of evolocumab.
BACKGROUND: Evolocumab, a fully human monoclonal antibody against proprotein convertase subtilisin/kexin type 9 (PCSK9), significantly reduced LDL-C in phase II trials. 
BACKGROUND: Evolocumab, a monoclonal antibody that inhibits proprotein convertase subtilisin/kexin type 9 (PCSK9), significantly reduced low-density lipoprotein (LDL) cholesterol levels in phase 2 studies. 
Effects of evolocumab (AMG 145), a monoclonal antibody to PCSK9, in hypercholesterolemic, statin-treated Japanese patients at high cardiovascular risk--primary results from the phase 2 YUKAWA study.

Answer: Evolocumab (AMG145) is a fully human monoclonal antibody to proprotein convertase subtilisin/kexin type 9 (PCSK9) that demonstrated marked reductions in plasma low-density lipoprotein cholesterol concentrations in statin-intolerant patients.
Exact answer: proprotein convertase subtilisin/kexin type 9