CGRP-monoclonal antibodies in Japan: insights from an online survey of physician members of the Japanese headache society.

Background: Anti-calcitonin gene-related peptide monoclonal antibodies (CGRPmAbs) have greatly changed migraine treatment options. In Japan, although CGRPmAb guidelines (≥ 4 monthly migraine days (MMDs) and ≥ 1 previous preventive failure) are well-acknowledged, the actual use of CGRPmAbs and the circumstances of the related headache care are unknown.

Methods: We conducted an online survey of Japanese Headache Society members, inquiring about the physicians' experience with CGRPmAbs and how they make decisions related to their use.

Results: Of the 397 respondents, 320 had prescribed CGRPmAbs. The threshold number of previous preventive failures for recommending a CGRPmAb was two for the majority of the respondents (n = 170, 54.5%), followed by one (n = 64, 20.5%). The MMD threshold was ≥ 4 for 71 respondents (22.8%), ≥ 6 for 68 (21.8%), ≥ 8 for 76 (24.4%), and ≥ 10 for 81 (26.0%). The respondents tended to assess treatment efficacy after 3 months (episodic migraine: n = 217, 69.6%, chronic migraine: n = 188, 60.3%). The cost of CGRPmAbs was described by many respondents in two questions: (i) any request for a CGRPmAb (27.7%), and (ii) the most frequently reported reason for responders to discontinue CGRPmAbs (24.4%).

Conclusions: Most of the respondents recommended CGRPmAbs to patients with ≥ 2 preventive failures, followed by ≥ 1. The MMD threshold ranged mostly from ≥ 4 to ≥ 10. The concern for costs was raised as a major limiting factor for prescribing CGRPmAbs.