Outcomes, unmet needs, and challenges in the management of patients who withdraw from anti-CGRP monoclonal antibodies: A prospective cohort study.

Background: The anti-calcitonin gene-related peptide (CGRP), or its receptor (CGRP/R) monoclonal antibodies (mAbs), offer targeted, effective, and tolerated drugs for migraine. However, about 25% of patients fail to achieve a clinically meaningful response, usually leading to discontinuation. These patients often have a lengthy migraine history and multiple prior preventive treatment failures, resulting in limited therapeutic options. Herein, we describe the cause for and outcome of withdrawal of anti-CGRP/R mAb and evaluate the treatment course until discontinuation.

Methods: We conducted a prospective analysis on migraine patients attending the Florence Headache Center in Italy, who discontinued treatment with anti-CGRP/R mAbs. The primary objectives were to describe the reasons for anti-CGRP mAbs discontinuation and the treatment course. Secondary objectives were the evaluation of the absolute change from baseline in monthly headache days, response rates, persistence in medication overuse, absolute change from baseline of the overall number and days of analgesics use per month, change of MIDAS and HIT-6 at three, six, and 12 months, and the last month of treatment.

Results: Among 472 patients, 136 (28.8%) discontinued mAb treatment after an average of 9.0 ± 6.1 (mean ± SD) months. The majority (96/136, 70.6%) discontinued due to ineffectiveness, followed by lost to follow-up during treatment (18/136, 13.1%) and adverse events (10/136, 7.3%). In total, 77.9% of the 136 patients ceased treatment within the first year. Following discontinuation, 48.5% initiated new pharmacological treatment, 39.7% were lost to follow-up, and 11.8% opted not to start another treatment. The majority of patients that started a new pharmacology treatment switched to another anti-CGRP/R (46/68, 67.6%). The second most-used treatment was onabotulinumtoxinA (7/68, 10.2%; all patients in this subgroup were naïve to this treatment), followed by an anticonvulsive medication (7/68, 10.2%). The response status (≥50% reduction in monthly headache days) was achieved by 30.5%, 34.6%, and 40.0% of patients at month 3, 6, and 12 of treatment, respectively. Considering only the comprehensive last month of treatment before withdrawn the percentage of responders was 16.9%.

Conclusion: Although anti-CGRP/R mAbs have provided a substantial amelioration of migraine management, a relevant proportion of patients remains unresponsive and requires additional therapeutic support. Further research is required to identify non-responder features and address unmet needs in migraine treatment.