Prospective real-world analysis of OnabotulinumtoxinA in chronic migraine post-National Institute for Health and Care Excellence UK technology appraisal.

BACKGROUND AND
PURPOSE: The National Institute for Health and Care Excellence (NICE) in the UK recommends the use of OnabotulinumtoxinA (BoNTA, Botox® ) in the management of chronic migraine (CM) following specific guidelines within the National Health Service. In view of the lack of data on the efficacy of this therapy following implementation of these guidelines in clinical practice and on the evaluation of guidance compliance, we aimed to evaluate the effectiveness and safety of BoNTA in patients with CM following the NICE guidelines.
METHODS: This was a prospective real-life audit study.
RESULTS: After two treatments, 127 of 200 patients (63.5%) obtained at least a 30% reduction in headache days. Those who continued the treatment up to 3 years reported a stable beneficial effect compared with baseline. Amongst responders, 68 patients (53.5%) were reclassified as episodic migraineurs. A total of 57 of these patients (83.8%) converted to an episodic migraine pattern at 6-month follow-up. The majority of those whose migraine became episodic after BoNTA extended the treatment intervals beyond 3 months (range 4-8 months) before noticing any worsening of headache. We observed no significant differences in the efficacy measures in patients treated with 155 U BoNTA compared with those treated with >155 U BoNTA.
CONCLUSIONS: When administered according to the NICE guidance, BoNTA produced a clinically meaningful effect in the long-term management of CM with and without medication overuse headache. Treatment discontinuation when CM becomes episodic may be useful in clinical practice to identify those who may benefit from extended treatment intervals. Our clinical experience indicates a lack of additional benefit from using the 'follow-the-pain' paradigm.