What are the indications, dosing regimen, and monitoring recommendations for Repatha (evolocumab) in adults with heterozygous or homozygous familial hypercholesterolemia or established atherosclerotic cardiovascular disease?

Repatha (Evolocumab): Indications, Dosing, and Monitoring

Repatha (evolocumab) is a PCSK9 inhibitor indicated for adults with established atherosclerotic cardiovascular disease (ASCVD) to reduce major adverse cardiovascular events, and as adjunctive therapy in adults and pediatric patients ≥10 years with heterozygous or homozygous familial hypercholesterolemia when LDL-C goals are not achieved with maximally tolerated statins and ezetimibe. 1

Primary Indications

1. Established ASCVD (Secondary Prevention)

• Reduces risk of: CV death, myocardial infarction, stroke, unstable angina requiring hospitalization, or coronary revascularization 1
• Evidence: The FOURIER trial demonstrated a 15% relative risk reduction in major CV events (HR 0.85,95% CI 0.79-0.92, NNT=67) over 2.2 years in patients with clinical ASCVD and LDL-C ≥1.8 mmol/L (≥70 mg/dL) despite maximally tolerated statin therapy 2
• When to use: LDL-C remains ≥70 mg/dL (1.8 mmol/L) on maximally tolerated statin ± ezetimibe 2, 3

2. Heterozygous Familial Hypercholesterolemia (HeFH)

• Adults: Adjunct to diet and maximally tolerated statin ± ezetimibe 1
• Pediatric patients ≥10 years: Adjunct to diet and other LDL-C-lowering therapies 1
• Threshold for initiation:
  • Ages 30-75 years with LDL-C ≥100 mg/dL (2.6 mmol/L) despite maximal statin + ezetimibe 4
  • Achieves ≥50% additional LDL-C reduction 4
• Evidence: Long-term data show sustained 54-60% LDL-C reduction over 4 years with good tolerability 5, 6

3. Homozygous Familial Hypercholesterolemia (HoFH)

• Adults and pediatric patients ≥10 years: Adjunct to other LDL-C-lowering therapies 1
• Important caveat: Most effective in patients WITHOUT biallelic LDLR null mutations 7
• Response threshold: Continue only if ≥15% additional LDL-C reduction achieved 7
• Evidence: Mean 21% LDL-C reduction in HoFH patients; up-titration to every-2-week dosing improved response to 30% 5

4. Severe Primary Hypercholesterolemia (Non-FH)

• Consider when: Baseline LDL-C ≥220 mg/dL AND LDL-C ≥130 mg/dL despite maximal statin + ezetimibe 4

Dosing Regimens

Standard Dosing (Adults and Pediatric ≥10 years with ASCVD or HeFH)

• Option 1: 140 mg subcutaneously every 2 weeks 1
• Option 2: 420 mg subcutaneously once monthly 1
• Switching regimens: Administer first dose of new regimen on next scheduled date of prior regimen 1

HoFH-Specific Dosing

• Initial: 420 mg once monthly 1
• Up-titration: Increase to 420 mg every 2 weeks if clinically meaningful response not achieved after 12 weeks 1
• Patients on apheresis: May initiate 420 mg every 2 weeks to correspond with apheresis schedule; administer AFTER apheresis session 1

Administration Details

• Route: Subcutaneous injection into abdomen, thigh, or upper arm 1
• Rotate injection sites with each administration 1
• Available formulations:
  • 140 mg/mL prefilled SureClick® autoinjector 1
  • 140 mg/mL prefilled syringe 1
  • 420 mg/3.5 mL Pushtronex® system (on-body infusor) 1

Latex Considerations

Critical: Some presentations contain dry natural rubber (latex derivative) in needle cover. Prescribe latex-free presentation for latex-sensitive individuals 1

Monitoring Recommendations

LDL-C Assessment

• Timing: Assess LDL-C when clinically appropriate; LDL-lowering effect measurable as early as 4 weeks after initiation 1
• Baseline: Measure LDL-C at week 48 after starting evolocumab to achieve median 0.8 mmol/L (interquartile range 0.5-1.2 mmol/L) 2

Treatment Targets by Population

Very High-Risk ASCVD:

• LDL-C <55 mg/dL (1.4 mmol/L) + ≥50% reduction from baseline 8
• Consider <40 mg/dL for highest-risk patients 8

HeFH:

• Primary prevention: LDL-C <100 mg/dL (2.6 mmol/L) 4
• With ASCVD: LDL-C <70 mg/dL (1.8 mmol/L) 4

HoFH:

• Without ASCVD: LDL-C <100 mg/dL (2.6 mmol/L) 7
• With ASCVD: LDL-C <70 mg/dL (1.8 mmol/L) 7
• With symptomatic ASCVD: LDL-C <55 mg/dL (1.4 mmol/L) 7

Safety Monitoring

• Adverse events: Most common are nasopharyngitis, upper respiratory tract infection, influenza, back pain, and injection site reactions 1
• Hypersensitivity: Angioedema has occurred; discontinue if serious hypersensitivity reactions develop 1
• Contraindication: History of serious hypersensitivity to evolocumab or excipients 1

Clinical Decision Algorithm

Step 1: Confirm diagnosis (ASCVD, HeFH, HoFH, or severe primary hypercholesterolemia)

Step 2: Optimize background therapy

• Maximize statin dose (unless intolerant)
• Add ezetimibe if not already prescribed

Step 3: Assess LDL-C on optimized therapy

• ASCVD: If ≥70 mg/dL → add evolocumab 2, 3
• HeFH: If ≥100 mg/dL → add evolocumab 4
• HoFH: Initiate evolocumab regardless of LDL-C level 7

Step 4: Select dosing frequency

• Standard: Choose 140 mg Q2W or 420 mg monthly based on patient preference
• HoFH on apheresis: Consider 420 mg Q2W aligned with apheresis schedule

Step 5: Assess response at 12 weeks

• HoFH: If <15% additional reduction, consider up-titration to Q2W dosing or alternative therapy (evinacumab) 7
• All others: Continue if achieving target or meaningful reduction

Important Caveats

Primary Prevention Limitation

There are currently NO RCT data supporting PCSK9 inhibitor use for CV event reduction in patients without established ASCVD (primary prevention) or FH 2. The 2025 AACE guidelines conditionally recommend AGAINST evolocumab in adults without ASCVD who may tolerate other lipid-lowering medications 3.

Statin Intolerance

In complete statin intolerance, evolocumab is a reasonable option for LDL-C lowering, though evidence for ASCVD risk reduction as monotherapy is limited 2. The GAUSS-3 trial showed 36% greater LDL-C reduction vs ezetimibe with similar muscle symptom rates (21% vs 29%, p=0.17) 2.

Cost and Access Considerations

While not explicitly stated in guidelines, the high cost of PCSK9 inhibitors necessitates careful patient selection based on cardiovascular risk stratification and failure of less expensive therapies 9.