Erenumab
Overview
Erenumab is a fully human monoclonal antibody that targets the calcitonin gene-related peptide receptor, a key pathway involved in the development of migraine headaches. By blocking this receptor, it prevents the binding of calcitonin gene-related peptide, a neuropeptide associated with vasodilation and pain signaling during migraine attacks. This targeted mechanism helps reduce the frequency and severity of migraines without affecting broader neurological function. Erenumab is administered as a subcutaneous injection and is designed for preventive therapy rather than acute treatment. It is typically used in patients with episodic or chronic migraine who require long-term prophylaxis. Its introduction marked a significant advancement as one of the first therapies specifically developed to target migraine pathophysiology rather than general pain or neurological modulation.
Background and Date of Approval
Erenumab was developed as a novel biologic therapy targeting the calcitonin gene-related peptide receptor to address unmet needs in migraine prevention. It received approval from the United States Food and Drug Administration on May 17, 2018 for the preventive treatment of migraine in adults. This approval was based on multiple randomized clinical trials demonstrating a significant reduction in monthly migraine days compared to placebo. It was the first therapy approved specifically to block the CGRP receptor, representing a new class of migraine-specific treatments. Regulatory approvals have also been granted in other regions, including Europe, for similar indications, supporting its widespread clinical adoption.
Uses
Erenumab is indicated for the preventive treatment of migraine in adults, including both episodic and chronic migraine. It is used to reduce the frequency of migraine attacks and improve quality of life in patients with frequent or disabling headaches. The drug is used as monotherapy in most cases but may be combined with other preventive or symptomatic treatments depending on patient needs.
Administration
Erenumab is administered as a subcutaneous injection using a prefilled syringe or autoinjector. It is typically given once monthly, with dosing options commonly including 70 mg or 140 mg depending on clinical response. The medication is designed for self-administration after appropriate training. Treatment is ongoing and guided by clinical response, with regular evaluation of migraine frequency and severity.
Side Effects
Common side effects include injection site reactions such as pain, redness, or swelling, as well as constipation and muscle cramps. Some patients may also experience mild discomfort or irritation at the injection site. These effects are generally mild and manageable under medical supervision.
Warnings
Serious adverse events include hypersensitivity reactions such as rash, swelling, or difficulty breathing. Severe constipation requiring medical intervention has been reported. There is also a potential risk of increased blood pressure or worsening of pre-existing hypertension. Although rare, these risks require monitoring during treatment, especially in patients with cardiovascular risk factors.
Precautions
Patients should be evaluated for cardiovascular risk factors before initiating therapy. Blood pressure monitoring may be required during treatment. As a monoclonal antibody, erenumab has minimal cytochrome-mediated drug interactions. However, clinical caution is advised when used alongside other therapies affecting vascular or neurological pathways. Limited data are available in pregnancy, so use requires careful risk assessment.
Expert Tips
Erenumab is best suited for patients with frequent migraines who have not responded adequately to traditional preventive therapies. Patient education on proper injection technique is essential for adherence. Clinical monitoring should focus on reduction in migraine frequency and tolerability. Clinicians should be aware of potential constipation and blood pressure changes during therapy. Coordination with neurology specialists may help optimize treatment outcomes in complex cases.