The Phase 3b FOCUS study demonstrated the efficacy and tolerability of fremanezumab, a humanised IgG2Δa monoclonal antibody that selectively targets the calcitonin gene-related peptide, for migraine prevention in patients with documented inadequate response to 2-4 prior preventive treatment classes. This subgroup analysis aimed to evaluate acute medication use in fremanezumab treated patients who had baseline medication overuse (MO; any acute medication ≥15 days/month or triptans, ergots, or combination medications ≥10 days/month).

In the double-blind (DB) period (DBP) of FOCUS, patients were randomised (1:1:1) to quarterly/monthly fremanezumab, or placebo. Patients completing the DBP entered the open-label extension (OLE) and received monthly fremanezumab; results from OLE are stratified by DB randomisation group. Changes from baseline in monthly average days of acute medication use and proportions of patients reverting to no MO were evaluated.

Patients with MO (427/838) had significant reductions in acute medication use with quarterly (least squares mean change, −3.8) or monthly (−4.7) fremanezumab during the DBP, versus placebo (−0.7; P<0.0001), which increased in OLE (quarterly, −6.1; monthly, −6.9; placebo, −5.0). A higher proportion of patients treated with quarterly or monthly fremanezumab reverted to no MO during the DBP, versus placebo (39% and 42% vs 13%), which further increased during the OLE (quarterly, 48%; monthly, 46%; placebo, 41%).

Fremanezumab patients with prior inadequate response to 2-4 prior classes of preventive medications and MO experienced a reduction in acute headache MO.