Background

The advent of monoclonal antibodies targeting proprotein convertase subtilisin/kexin type 9 (PCSK9) ushered in a new era of dyslipidemia pharmacotherapy. The first two antibodies targeting PCSK9 (evolocumab, alirocumab) approved by the United States Food and Drug Administration (FDA) provided significant and sustained reductions in atherogenic lipids and a reduced risk of atherosclerotic cardiovascular disease (ASCVD) events. More recently, phase 3 trials of inclisiran--a small interfering RNA-based agent targeting PCSK9--reported similar lipid lowering effects and preliminary evidence of ASCVD risk reduction, although significant questions remain regarding the extent of benefits across cardiovascular outcomes.

Methods

We conducted a systematic review and meta-analysis (random effects model) of the available data on lipid lowering, incidence of atherosclerotic cardiovascular disease (ASCVD) events, and safety of pharmacologic agents targeting PCSK9.

Results

A significant and consistent reduction in low-density lipoprotein cholesterol (LDL-C) was observed across all agents (-51%, [95% confidence interval : -61%, -41%]). Despite the impressive reduction in LDL-C, the individual effects on mortality, cardiovascular death, myocardial infarction (MI), and stroke remained nonsignificant. However, a consistent reduction was observed in the composite outcomes of MI, stroke, and cardiovascular death [relative risk (95% CI): 0.80 (0.73-0.87)] and MI, stroke, unstable angina (requiring revascularization), and cardiovascular death [RR (95% CI): 0.85 (0.74-0.97)]. In terms of safety outcomes, there was no significant difference in severe adverse events, new onset diabetes, neurocognitive disorders, or myalgia. Meanwhile, injection site reaction was more frequent in patients receiving these agents compared to placebo [RR 2.11 (95% CI): 1.26-3.54].

Conclusion

These findings suggest a class effect for favorable lipid changes and a low risk of serious adverse events among pharmacologic agents targeting PCSK9. Although there is compelling evidence that PCSK9-targeting agents reduce the risk of some cardiovascular outcomes, adequately powered studies with longer follow-up may be needed to fully characterize the magnitude of benefits across the cardiovascular spectrum.