Impact of multiple treatment cycles with anti-CGRP monoclonal antibodies on migraine course: focus on discontinuation periods. Insights from the multicenter, prospective, I-GRAINE study

Objectives While a single 12-month treatment cycle (TrC) with anti-CGRP mAbs is not disease-modifying for most patients, there is limited understanding of the effects of multiple TrCs on migraine course. We evaluated whether a second TrC might modify the migraine course by comparing the occurrence of migraine relapse after discontinuation of the second TrC to that following the cessation of the first TrC. Methods In a real-life, multicenter, prospective study we considered all consecutive patients diagnosed with high-frequency episodic migraine (HFEM) or chronic migraine (CM) with > 3 treatment failures and treated with any anti-CGRP mAbs for >= 2 consecutive 12-month TrCs who were responders at week 12. The primary endpoint was the change in monthly migraine days (MMD) for HFEM or monthly headache days (MHD) for CM at the first month of treatment discontinuation after the second TrC (D2) compared to the first TrC (D1). Secondary endpoints included variations in monthly analgesic medications (MAM), Numeric Rating Scale (NRS), and Headache Impact Test (HIT-6) scores, >= 50%, >= 75%, and 100% response rates, and relapse from episodic migraine to CM and from no-medication overuse (MO) to MO at D2 vs. D1. Results One-hundred-seventy-eight patients completed two 12-month TrCs with anti-CGRP mAbs. At D2, patients experienced a significant reduction in MMD (- 0.6, p = 0.028), MHD (- 2.6, p < 0.001), monthly analgesic medications (- 2.0, p < 0.001), and HIT-6 score (- 2.2, p < 0.001) compared to D1, indicating improved effectiveness. The >= 50% response rate at weeks 45-48 during the first TrC was 95.5%, while at weeks 45-48 of the second TrC was 99.4%. Corresponding rates at D1 was 20.2% whereas at D2 was 51.6% (p < 0.0001). No statistical difference emerged in >= 75% and 100% responders. The relapse rate from episodic migraine to CM at D2 was lower than at D1 (12.3% vs 30.4%; p = 0.0002) Fewer patients experienced relapse from no-MO to MO at D2 compared to D1 (29.5% vs 68.7%; p = 0.00001). Discussion A second TrC with anti-CGRP mAbs demonstrated clinical improvements compared to the first one, as indicated by a milder migraine relapse at D2 compared to D1. Multiple TrCs with anti-CGRP mAbs could progressively modify migraine evolution by reducing CGRP-dependent neuroinflammatory nociceptive inputs to the brain.