Failure of an anti-CGRP monoclonal antibody in the treatment of migraine. Is it worthwhile trying another one?

Introduction. Migraine is a highly prevalent neurological disease and the search for an effective treatment to improve the patient's quality of life is essential. In 2018, anti-CGRP monoclonal antibodies were approved in Spain as a preventive treatment, and have proved to be effective in reducing the number of migraine crisis per month compared to placebo. Patients and methods. We conducted a descriptive and retrospective study of 14 patients suffering from high-frequency or chronic episodic migraine, under follow-up in our headache unit, in whom an anti-CGRP monoclonal was changed due to its ineffectiveness. Epidemiological data and variables related to the response to both drugs were collected, such as headache days per month and migraine days per month, as well as validated quality of life scales (Migraine Disability Assessment Scale and Headache Impact Test-6). Results. 50% of patients were males, with a median age of 46.5 years and 92% were diagnosed with chronic migraine. A follow-up of 6 to 12 months after the change of treatment was performed in 91.6% and significant improvement was observed in 33% of the patients. In addition, 50% had an initial response after three doses of the first monoclonal drug. Conclusions. In our series, 66% of patients who did not respond to a first drug responded initially to the switch and this improvement was maintained in 36% of them. Larger studies are needed to clarify this difference in response to different anti-CGRP monoclonal antibodies.