What are the pros and cons of Ajovy (fremanezumab) and Amovig (erenumab) for managing migraines?

Comparison of Ajovy (Fremanezumab) and Aimovig (Erenumab) for Migraine Management

Both Ajovy (fremanezumab) and Aimovig (erenumab) are highly effective CGRP monoclonal antibodies for migraine prevention with strong evidence supporting their use, but they should be reserved as second-line options after trials of less expensive alternatives like beta-blockers, antiseizure medications, or antidepressants due to their high cost.

Efficacy Comparison

Shared Benefits

• Both medications have received "strong for" recommendations for prevention of episodic migraine (EM) and chronic migraine (CM) in the 2023 VA/DoD Clinical Practice Guidelines 1
• Both demonstrate significant reductions in:
  • Monthly migraine days
  • Monthly headache days of moderate/severe intensity
  • Use of acute headache medications
  • Migraine-associated symptoms (photophobia, phonophobia, nausea)

Efficacy Data for Ajovy (Fremanezumab)

• Available in both monthly (225 mg) and quarterly (675 mg) dosing options 2
• Clinical trials showed:
  • For episodic migraine: 3.7 fewer monthly migraine days (monthly dosing) and 3.4 fewer days (quarterly dosing) compared to 2.2 days with placebo 2
  • For chronic migraine: 4.6 fewer monthly headache days (monthly dosing) and 4.3 fewer days (quarterly dosing) compared to 2.5 days with placebo 2
• Approximately 40-47% of patients achieve ≥50% reduction in monthly migraine days 2, 3
• Onset of action can be seen within the first week of treatment 4

Efficacy Data for Aimovig (Erenumab)

• First FDA-approved CGRP monoclonal antibody
• Similar efficacy profile to fremanezumab with significant reductions in monthly migraine days
• Unique mechanism as a CGRP receptor antagonist (rather than targeting the CGRP ligand like fremanezumab)

Administration Differences

• Ajovy (Fremanezumab):

  • Flexible dosing: monthly (225 mg) or quarterly (675 mg) subcutaneous injections 2
  • Quarterly dosing option may improve adherence for some patients

• Aimovig (Erenumab):

  • Monthly subcutaneous injections only
  • Post-marketing studies have shown increased risk for development or worsening of hypertension 1
  • FDA has revised prescribing information to include hypertension warning 1

Safety Profile

Shared Safety Features

• Both medications are generally well-tolerated
• Common side effects include injection site reactions
• Neither medication causes sedation, cognitive impairment, or weight gain seen with many traditional preventives
• Low discontinuation rates due to adverse events (<1%) 5

Safety Considerations for Aimovig (Erenumab)

• Unique warning for hypertension risk not present with fremanezumab 1
• Contraindicated in patients with uncontrolled hypertension 1

Cost Considerations

• Both medications are extremely expensive compared to traditional preventives
• Annual treatment costs range from $7,071 to $22,790 1
• Traditional preventives are substantially less expensive:
  • Metoprolol: $123/year
  • Propranolol: $393/year
  • Amitriptyline: $67/year
  • Valproate: $274/year
  • Venlafaxine: $378/year 1

Special Populations

• Medication Overuse Headache: Both medications have shown efficacy in reducing medication overuse headache in chronic migraine patients (approximately 80% of patients achieved ≥50% reduction in headache days and analgesic intake) 6

• Treatment-Resistant Patients: Both medications have demonstrated efficacy in patients with documented inadequate response to 2-4 classes of preventive medications 5

Clinical Decision Algorithm

1. First-line options (try before CGRP monoclonal antibodies):

   • Beta-blockers (propranolol 80-240 mg/day or metoprolol)
   • Antiseizure medications (valproate 500-1500 mg/day, except in women of childbearing potential)
   • Antidepressants (amitriptyline 30-150 mg/day or venlafaxine) 1, 7

2. Consider CGRP monoclonal antibodies when:

   • Patient has failed or cannot tolerate at least 2 first-line preventives
   • Patient has ≥4 migraine days per month or ≥2 migraine days with significant disability
   • Patient has high-frequency episodic or chronic migraine 1, 7

3. Choose Ajovy (fremanezumab) over Aimovig (erenumab) when:

   • Patient has hypertension or cardiovascular risk factors
   • Patient prefers quarterly dosing option
   • Patient has difficulty with medication adherence

4. Choose Aimovig (erenumab) over Ajovy (fremanezumab) when:

   • Patient prefers a CGRP receptor antagonist rather than a CGRP ligand antagonist
   • Patient has previously responded well to other receptor antagonists

Common Pitfalls to Avoid

1. Starting CGRP monoclonal antibodies as first-line therapy - Despite their efficacy, guidelines recommend trying less expensive options first 1, 7

2. Inadequate trial duration - Allow 2-3 months to determine efficacy of any preventive medication 7

3. Not addressing medication overuse - Both medications can help reduce medication overuse headache, but addressing overuse of acute medications is still important 6

4. Not monitoring for hypertension with erenumab - Regular blood pressure monitoring is recommended due to post-marketing safety findings 1

5. Discontinuing too early - Benefits may continue to improve over 6 months of treatment 5