Erenumab is a human monoclonal antibody that binds to the calcitonin gene-related peptide (CGRP) receptor, which is located at sites that are relevant to migraine pathophysiology, such as the trigeminal ganglion. CGRP levels have been shown to increase significantly during migraine and return to normal with headache relief.
The NICE guidance recommends erenumab as an option for preventing migraine in adults only if:
- they have >4 migraine days a month
- >3 preventive drug treatments have failed
- the 140mg dose of erenumab is used, and
- the company provides it according to the commercial arrangement
NICE recommends that treatment with erenumab should be stopped after 12 weeks if:
- the frequency of episodic migraine (<15 headache days per month) does not reduce by >50% or
- the frequency of chronic migraine (>15 headache days per month with >8 having features of migraine) does not reduce by >30%
The licensed dose of erenumab is 70mg by subcutaneous injection once every four weeks, increasing to 140mg once every four weeks if necessary. In clinical studies, most patients responding to therapy showed clinical benefit within three months. For patients who have shown no response after three months it is recommended that discontinuation of treatment be considered.