| | Conditions & Treatments | Cholesterol

PCSK9 Inhibitors: The Injectable Cholesterol Game-Changer

A New Class of Cholesterol-Lowering Therapy

PCSK9 inhibitors (alirocumab/Praluent, evolocumab/Repatha) are monoclonal antibodies that dramatically lower LDL cholesterol by preventing the PCSK9 protein from degrading LDL receptors on liver cells. More receptors = more LDL cleared from blood = 50–60% LDL reduction.

How They Work

PCSK9 normally binds LDL receptors, targeting them for destruction. Inhibitors block this interaction, increasing LDL receptor availability on hepatocytes → enhanced LDL clearance → dramatic LDL lowering.

Clinical Benefits

LDL reduction: 50–60% additional lowering on top of statins
Cardiovascular outcomes: FOURIER (evolocumab) and ODYSSEY (alirocumab) trials showed ~15% relative risk reduction in MACE (heart attack, stroke, CV death)
HDL increase: Modest 5–10% rise
Lp(a) reduction: 20–30% decrease in lipoprotein(a), an independent risk factor

FDA-Approved Indications

Heterozygous familial hypercholesterolemia (HeFH) requiring additional LDL lowering
Clinical ASCVD (prior MI, stroke, PAD) needing further LDL reduction
Homozygous FH (HoFH) — evolocumab only
Primary hyperlipidemia (evolocumab) as adjunct to diet/statins

Dosing & Administration

Alirocumab: 75 mg SC every 2 weeks or 300 mg monthly
Evolocumab: 140 mg SC every 2 weeks or 420 mg monthly
Self-injected via autoinjector/prefilled syringe; refrigerated storage

Side Effects & Safety

Common (≥5%)	Serious (Rare)	Monitoring
Injection site reactions (redness, pain)	Neurocognitive effects (confusion, memory) — causality unclear	Lipid panel 4–12 weeks after initiation
Nasopharyngitis, flu-like symptoms	Hypersensitivity/anaphylaxis	Liver function (rare elevations)
Back pain, myalgia	No increased diabetes risk (unlike statins)	Cognitive symptoms if reported

Cost & Access

List price: ~$5,000–6,000/year (significantly reduced from launch)
Insurance: Requires prior authorization; typically for high-risk patients not at goal on maximally tolerated statin ± ezetimibe
Patient assistance: Manufacturer programs for eligible uninsured/underinsured

How They Compare to Other Lipid Therapies

Therapy	LDL Reduction	CV Outcomes Data	Cost/Year	Route
High-intensity statin	50%	Robust	$50–300 (generic)	Oral daily
Ezetimibe	15–20%	IMPROVE-IT (modest)	$100–1,000	Oral daily
Bempedoic acid	15–25%	CLEAR Outcomes (primary prevention)	$3,000–4,000	Oral daily
PCSK9 inhibitors	50–60%	FOURIER, ODYSSEY	$5,000–6,000	SC q2w/monthly
Inclisiran (siRNA)	50%	ORION-4 ongoing	~$3,000	SC every 6 months

Decision Framework

Discuss with a cardiologist/lipid specialist. Consider if: LDL >70 mg/dL on max tolerated statin ± ezetimibe with ASCVD, or LDL >100 mg/dL with HeFH. Inclisiran offers similar efficacy with twice-yearly dosing—an emerging alternative.