In clinical practice, many patients on erenumab treatment have chronic migraine (CM). As per this real-life data from an Italian region, the percentage of patients changing to EM was approximately half at 1st month and soared up to 3 quarters at 5th month. The high rate of conversion to EM in these difficult-to-treat patients with a prior CM and many earlier preventive treatment disappointments supports erenumab’s effectiveness for preventive treatment of CM patients.

This real-life study aimed to examine the rate and potential predictors of change from chronic migraine (CM) to episodic migraine (EM).

A subgroup analysis was performed in patients treated with erenumab in central Italy. Treatment was provided as per existing clinical practice. The patients satisfying the definition of CM for 3 months prior to erenumab usage and with approximately 6 months of follow-up after the erenumab use were included. The rate of change to EM from starting to months 4 to 6 of treatment and through each month of treatment was investigated. The reduction in monthly headache days (MHDs), acute medicine days, and average headache intensity on a Numerical Rating Scale (NRS) to examine the clinical validity of conversion to EM was noted.

Ninety-one patients with CM were included. At Months 4–6, 62 patients (68.1%) changed from CM to EM; the percentage of converters augmented from Month 1 till Month 5 in the following figure:

Figure: Rates of conversion to episodic migraine at Months 4–6 and following each month of treatment as per headache days per month

On the whole, median MHDs reduced from 26.5 to 7.5 than with baseline, whereas median acute medication days reduced from 21 to 6 and median NRS scores reduced from 8 to 6. There were substantial decreases observed both in converters and in non-converters. No noteworthy indicators of conversion to EM among the patients’ baseline features were found.

About two-thirds of patients with CM changed to EM in 6 months of erenumab treatment. The acute medicine usage, MHDs and headache intensity reduced irrespective of change from CM to EM.