Clinical Evaluation After Discontinuation of Galcanezumab in Japanese Patients with Episodic and Chronic Migraine: Analysis of a Randomized, Placebo-Controlled Trial and Open-label Extension Study

Introduction This analysis of two Japanese clinical trials evaluated efficacy and safety after galcanezumab (GMB) discontinuation in patients with episodic migraine (EM) and chronic migraine (CM).Methods Data were from a 6-month, randomized, double-blind, placebo [PBO]-controlled primary trial (patients with EM) and a 12-month open-label extension trial (patients with EM/CM). Patients received 6 months' (primary) or 12/18 months' (extension) treatment with GMB 120 mg (GMB120) plus 240-mg loading dose or 240 mg (GMB240) with 4 months' post-treatment follow-up. Efficacy was assessed as number of monthly migraine headache days during post-treatment. Safety was assessed via post-treatment-emergent adverse events (PTEAEs).Results The analysis population included 186 patients from the primary trial (PBO N = 93; GMB120 N = 45; GMB240 N = 48), 220 patients with EM from the extension trial (PBO/GMB120 N = 57; PBO/GMB240 N = 55; GMB120/GMB120 N = 55; GMB240/GMB240 N = 53), and 55 patients with CM (GMB120 N = 28; GMB240 N = 27). In patients with EM receiving 6 months' GMB120, mean standard deviation (SD) monthly migraine headache days increased from 5.69 (4.64) at treatment end to 6.24 (4.37) at end of follow-up but did not return to pre-treatment levels (8.80 [2.96]). In the extension trial, mean monthly migraine headache days in patients with EM receiving GMB120 were 4.13 (3.85) after 12 months and 4.45 (3.78) at end of follow-up, and 3.59 (3.48) after 18 months and 3.91 (3.57) at end of follow-up. Monthly migraine headache days in patients with CM (12 months' GMB120) were 10.71 (4.61) at treatment end and 11.17 (5.64) at end of follow-up (pre-treatment 20.15 [4.65]). Similar results were seen for patients receiving GMB240. The most observed PTEAE after GMB discontinuation was nasopharyngitis.Conclusion Galcanezumab exhibited post-treatment efficacy for up to 4 months in Japanese patients with EM and with CM. No unexpected safety signals were observed.Clinical Trial Registration ClinicalTrials.gov, NCT02959177 and NCT02959190.