What is the recommended dose of Ajovy (fremanezumab) for migraine prophylaxis in an adult patient with chronic or episodic migraines?

Ajovy Dosing for Migraine Prophylaxis

Ajovy (fremanezumab) is administered subcutaneously at either 225 mg monthly OR 675 mg every 3 months (quarterly) for both episodic and chronic migraine prevention in adults. 1

FDA-Approved Dosing Regimens

Both dosing options are equally effective and the choice depends primarily on patient preference 1:

• Monthly regimen: 225 mg subcutaneous injection once per month 1
• Quarterly regimen: 675 mg subcutaneous injection every 3 months, administered as three consecutive 225 mg injections 1

For chronic migraine specifically, an alternative loading dose regimen exists: 675 mg initial dose followed by 225 mg monthly thereafter 1. However, the standard quarterly 675 mg dosing (without loading) is also FDA-approved and effective for chronic migraine 1.

Administration Details

• Inject subcutaneously in the abdomen, thigh, or upper arm 1
• Available as prefilled autoinjector or prefilled syringe, both containing 225 mg/1.5 mL 1
• For the 675 mg quarterly dose, administer three consecutive 225 mg injections at the same visit 1

Guideline Support and Evidence Strength

The 2024 VA/DoD guidelines provide a "Strong For" recommendation for fremanezumab in preventing both episodic and chronic migraine 2, placing it among the highest tier of preventive therapies alongside erenumab and galcanezumab.

The 2025 American College of Physicians guidelines similarly recommend CGRP monoclonal antibodies including fremanezumab for episodic migraine prevention 2.

Clinical Efficacy Data

Fremanezumab demonstrates robust efficacy in FDA trials 1:

• Episodic migraine: Reduces monthly migraine days by 3.4-3.7 days versus 2.2 days with placebo (difference of 1.2-1.5 days) 1
• Responder rates: 44-48% of patients achieve ≥50% reduction in monthly migraine days versus 28% with placebo 1
• Acute medication reduction: Decreases monthly acute headache medication use by 1.3-1.4 days compared to placebo 1, 3

Real-world studies suggest even greater effectiveness than clinical trials, with 76.5% of episodic migraine patients and 58.3% of chronic migraine patients achieving ≥50% response rates 4.

Pharmacokinetic Considerations

• Steady-state concentrations achieved after approximately 6 months of treatment 1
• Half-life of approximately 31 days 1
• No dose adjustments needed for age, sex, race, weight, or mild hepatic/renal impairment 1
• No drug-drug interactions with cytochrome P450 substrates or other migraine medications 1

Safety Profile

• Most common adverse reaction: injection site reactions (≥5% incidence) 1
• Contraindicated only in patients with serious hypersensitivity to fremanezumab or excipients 1
• Very low incidence of anti-drug antibodies compared to other CGRP antibodies 5
• Treatment-emergent adverse events are uncommon (5.7%) and mild in real-world settings 4

Important Clinical Pearls

• Younger age predicts better treatment response (OR = 0.91 per year of age) 4
• Treatment benefits may continue to improve beyond 6 months, particularly in chronic migraine patients 4, 6
• 75% of chronic migraine patients revert to episodic migraine with fremanezumab treatment 4
• Fremanezumab reduces migraine-associated symptoms including nausea/vomiting, photophobia, and phonophobia 3
• Patients can use acute headache treatments concurrently without affecting fremanezumab efficacy 1

Dosing Selection Algorithm

Choose between monthly and quarterly dosing based on:

1. Patient preference for injection frequency - both regimens have equivalent efficacy 1
2. Adherence concerns - quarterly dosing may improve compliance in patients who struggle with monthly injections 7
3. For chronic migraine with severe baseline burden - consider the loading dose regimen (675 mg initial, then 225 mg monthly) 1