Neutropenia is Not a Known Side Effect of Aimovig (Erenumab)
Based on available evidence, neutropenia is not a recognized side effect of Aimovig (erenumab) treatment.
Evidence Assessment
The evidence does not support neutropenia as a side effect of Aimovig. In reviewing the available research:
A 12-month real-world safety study of erenumab reported common adverse events including constipation, skin reactions, fatigue, sleep disturbances, and nausea/emesis, but did not identify neutropenia as a reported adverse event 1.
Long-term efficacy and safety studies of erenumab over 52 weeks 2 and 5 years 3 did not identify neutropenia among the reported adverse events, despite comprehensive safety monitoring.
The most frequently reported adverse events in long-term erenumab treatment were nasopharyngitis, upper respiratory tract infection, and influenza, with no mention of neutropenia or other hematologic abnormalities 3.
Mechanism of Action and Safety Profile
Aimovig (erenumab) is a fully human monoclonal antibody that selectively binds to and inhibits the calcitonin gene-related peptide (CGRP) receptor. Unlike some other medications that can cause neutropenia through direct bone marrow suppression or immune-mediated mechanisms, erenumab's mechanism of action does not suggest a pathway for neutropenia:
Erenumab works by blocking the CGRP receptor, which is primarily involved in pain signaling pathways relevant to migraine, rather than affecting bone marrow function or neutrophil production.
In contrast to medications known to cause neutropenia (such as azathioprine 4 or certain cancer treatments 4), erenumab does not have immunosuppressive properties that would directly affect white blood cell production.
Clinical Implications
If a patient on Aimovig develops neutropenia:
Consider other causes of neutropenia, including concomitant medications, infections, or underlying hematologic conditions.
Medications commonly associated with neutropenia include azathioprine 4, certain chemotherapeutic agents 4, and some antiarrhythmics like amiodarone 5.
Evaluate the timing and severity of neutropenia in relation to Aimovig administration and other potential causative factors.
Monitoring Recommendations
Routine monitoring of complete blood counts is not required specifically for patients on Aimovig based on current evidence.
If neutropenia is detected in a patient taking Aimovig, a thorough medication review and evaluation for other causes should be conducted before attributing it to Aimovig.
Conclusion
The current evidence does not support neutropenia as a side effect of Aimovig (erenumab). The established safety profile from multiple studies, including long-term follow-up data, does not identify neutropenia among the reported adverse events. If neutropenia occurs in a patient taking Aimovig, other causes should be investigated.