What is Repatha?
Repatha (evolocumab) is a fully human monoclonal antibody that blocks PCSK9 (proprotein convertase subtilisin/kexin type 9), administered subcutaneously to dramatically lower LDL cholesterol and reduce cardiovascular events in patients with atherosclerotic disease or familial hypercholesterolemia. 1
Mechanism of Action
Evolocumab works by binding to PCSK9, a circulating enzyme that normally promotes degradation of LDL receptors in the liver. By inhibiting PCSK9, evolocumab increases the number of LDL receptors available on liver cells to clear LDL cholesterol from the blood, resulting in substantial LDL-C reduction of 45-60% when added to statin therapy 2, 1.
FDA-Approved Indications
Repatha is approved for:
- Reducing cardiovascular risk (myocardial infarction, stroke, coronary revascularization) in adults with established atherosclerotic cardiovascular disease 2, 1
- Lowering LDL cholesterol in adults with primary hyperlipidemia (including heterozygous familial hypercholesterolemia) as adjunct to diet and maximally tolerated statin therapy 2, 1
- Treating pediatric patients aged ≥10 years with heterozygous or homozygous familial hypercholesterolemia 2, 1
Dosing and Administration
Standard dosing: 140 mg subcutaneously every 2 weeks OR 420 mg once monthly 2, 1
For homozygous familial hypercholesterolemia: Start with 420 mg monthly; may increase to 420 mg every 2 weeks if LDL-C goals not achieved after 12 weeks 2, 1
The medication is self-administered via prefilled autoinjector or syringe in the thigh, abdomen, or upper arm. Injection takes approximately 15 seconds 1.
Clinical Evidence for Cardiovascular Outcomes
The FOURIER trial demonstrated that evolocumab reduces major adverse cardiovascular events by 15% (p<0.001) in patients with atherosclerotic disease on statin therapy 2, 3. More recent evidence from VESALIUS-CV showed that in patients without prior myocardial infarction or stroke, evolocumab reduced 3-point MACE by 25% (HR 0.75; 95% CI 0.65-0.86; p<0.001) over 4.6 years of follow-up 4.
Long-term data from FOURIER-OLE (median 7.1 years follow-up) showed sustained benefit, with particularly favorable results in older patients ≥75 years: absolute risk reduction of 5.4% and number needed to treat of only 19 5.
Guideline-Recommended Use
According to the 2022 ACC Expert Consensus 2:
- Add PCSK9 inhibitors when LDL-C remains ≥100 mg/dL (2.6 mmol/L) on maximally tolerated statin plus ezetimibe in very high-risk patients
- For patients with severe familial hypercholesterolemia, thresholds may differ based on baseline LDL-C levels
The 2022 BMJ guidelines 6 provide strong recommendations for adding PCSK9 inhibitors in high and very high cardiovascular risk patients, but strong recommendations against use in low-risk patients due to burden without important benefits.
Safety Profile
Generally well tolerated with adverse effects including nasopharyngitis, upper respiratory infections, injection site reactions, and myalgia 2. No evidence of increased cognitive adverse effects was observed in major trials 2.
Important warnings:
- Hypersensitivity reactions including angioedema can occur (though rare) - discontinue immediately if serious reaction develops 1, 7
- Latex sensitivity: Some formulations contain dry natural rubber in needle covers 1
- No dose adjustment needed for renal or mild-to-moderate hepatic impairment 1
Practical Considerations
Storage: Refrigerate at 2-8°C; may keep at room temperature (20-25°C) for up to 30 days 1
Cost and access: Robust LDL-C reduction but expensive; typically requires prior authorization 2. Generic not available.
Pregnancy/lactation: No safety data in humans; avoid use during pregnancy unless benefits clearly outweigh risks 1