Fremanezumab for refractory migraine in patients with hereditary transthyretin amyloidosis: A case series

Background Anti-calcitonin gene-related peptide (CGRP) monoclonal antibodies (mAbs) are considered a safe and well-tolerated option for migraine prophylaxis. However, caution is advised in patients with vascular comorbidities. In hereditary transthyretin amyloidosis (ATTRv amyloidosis), amyloid deposition in leptomeningeal vessels has been reported, potentially leading to cerebral amyloid angiopathy. The efficacy and safety of anti-CGRP antibodies in patients with this condition have not been described. Methods We present three patients with ATTRv amyloidosis and refractory migraine who were treated with 225 mg of fremanezumab monthly. Results All patients reported a reduction of more than 30% in the number of monthly headache and migraine days, as well a relief from maximum pain intensity and an improvement in quality-of-life impact scales. Mild constipation was reported by one patient, while the other two experienced no adverse effects. Conclusion In our experience, treatment with fremanezumab was both effective and safe in patients with ATTRv amyloidosis. To the best of our knowledge, this is the first reported use of anti-CGRP monoclonal antibodies in ATTRv amyloidosis patients with chronic migraine.