Background and Importance The diagnosis of chronic migraine (CM) includes headaches for more than 15 days per month for at least three months and suffering this pain with migraine criteria for at least eight days The clinical manifestations of CM have a high impact on the quality of life of patients. Failure to control the pain can lead to a high risk of treatment abuse. Monoclonal antibodies such as fremanezumab are used as prophylactic treatment.

Aim and Objectives The objectives of this real-life study were to analyse the reversion of CM to episodic (EM) and evaluate the benefit on the symptomatology in young patients treated with botulinum toxin-resistant fremanezumab.

Material and Methods Patients aged 18–65 years diagnosed with CM and under neurological follow-up, treated for at least 3 months with fremanezumab as a 225mg monthly inyection were interviewed. The data to assess effectiveness were before treatment and at the time of the interview: monthly headache days (MHDs), monthly symptomatic medication days (MSMDs) and percentage of patients with symptomatic medication overuse (SMO). Converters were defined as those patients whose number of MHDs decreased to less than 15 days after at least three months of fremanezumab treatment. The criterion for considering strong medication use as abusive was set at taking medication at least 15 days a month.

Fifty-four patients were interviewed The median age of the study population was 51.5 years old (47.4–55.3, 95%CI), with a median treatment duration of 12 months (9.4–15.0, 95%CI). Fourty patients were converters to EM. The median of MHDs decreased from 28.7 (27.1–30.0, 95%CI) to 4.0 (3.9–6.4, 95% CI; p<0.001) in converters. The median of MSMDs fell from 28.9 (27.8–30.0, 95%CI) to 4.0 (3.0–4.6, 95%CI; p<0.001) in converters. The percentage of patients with SMO decreased from 97.5% to 2.5% (p<0.001) in converters.

Conclusion and Relevance The decrease in converters of all the effectiveness variables, shows a high benefit in patients‘ clinical and quality of life, supporting the outcomes obtained in clinical trials. The large decrease in the percentage of patients with SMO reflects the high ability to combat one of the most interrelated clinical consequences of CM.

Conflict of Interest No conflict of interest.