Background: MONONOFU, a multicenter, randomized, double-blind, placebo-controlled phase 2 study of Japanese patients with migraine, was pivotal for lasmiditan approval in Japan. However, treatment-emergent adverse events (TEAEs) were more common than in global studies. A detailed safety profile would assist patient management.
Research design and methods: Safety assessments in MONONOFU included specific terms reported, frequency, severity, time to onset, duration, TEAE management, common TEAE risk factors, and TEAE-efficacy associations.
Results: Of 846 participants, 691 were assessed for safety. The proportion of participants reporting ≥1 TEAE was 23.4% with placebo and 70.9% with lasmiditan; 87.3% of TEAEs with lasmiditan were mild. The most frequent TEAEs with lasmiditan, dizziness (39.4%) and somnolence (19.3%), started ≤1 hour postdose (median durations: 2.5 and 3.3 hours, respectively). Higher lasmiditan dose, but not patient factors including body size, was identified as a clinically meaningful predictor of dizziness and somnolence. There were no adverse consequences of neurological TEAEs, which did not appear to adversely affect lasmiditan efficacy.
Conclusions: In the MONONOFU study, TEAEs appeared typically mild, transient, and self-limiting. Lasmiditan may represent a useful and well-tolerated acute treatment option for smaller (body mass index <30 kg/m2) patients and Asian patients with migraine.
Keywords: 5-HT1F receptor; Japan; acute treatment; headache; lasmiditan; migraine disorders; phase 2; safety; serotonin agonist.