Alopecia as an emerging adverse event to CGRP monoclonal antibodies: Cases Series, evaluation of FAERS, and literature review

Background Alopecia is associated with erenumab post-marketing, but no cases have been described. Methods We describe two patients that reported temporary hair loss and review the FDA Adverse Event Reporting System (FAERS). Results The first patient experienced alopecia within three months of starting erenumab, which did not improve with ongoing use or transition to fremanezumab. The second patient reported alopecia within two weeks of starting erenumab, which continued after transition to galcanezumab; months later, there was also recurrent hair loss within one month of starting fremanzeumab. According to FAERS (last accessed 18 August 2022), alopecia was reported most with erenumab (1158), followed by galcanezumab (554), fremanezumab (175), eptinezumab (23), rimegepant (26), ubrogepant (4), and atogepant (3). Conclusion Most events were reported in women and non-serious. The potential mechanism of alopecia with drugs targeting calcitonin gene-related peptide or its receptor possibly includes disruptions in the microvascular circulation and other homeostatic mechanisms.