(214) Characteristics and drug utilization patterns of patients with migraine initiating erenumab in Nordic countries

Background: In 2018, erenumab, a calcitonin gene-related peptide (CGRP) receptor antagonist, was approved by the European Medicines Agency as a preventive migraine treatment for adults.

Objectives: To describe utilization of erenumab and characteristics of erenumab initiators in Denmark, Finland, Norway, and Sweden.

Methods: We report a subset of interim results from a regulator-mandated non-interventional study. Using data from nationwide registries from the four countries, we identified and described persons with migraine who initiated erenumab between August 2018 and December 2021. Erenumab was assumed to be initiated as an add-on if dispensing of a previous preventive migraine medication covered the erenumab initiation date. Erenumab persistence was estimated as the proportion of patients who remained continuous users of erenumab (i.e., did not discontinue or switch to another CGRP pathway antagonist or botulinum toxin).

Results: During the study period, 1253 individuals initiated erenumab in Denmark, 4124 in Finland, 7003 in Norway, and 4423 in Sweden. In all countries, >80% of erenumab initiators were women. Median age ranged between 43 (Norway) and 47 years (Sweden). Within 12 months prior to erenumab initiation, >90% had received at least one type of acute migraine medication. Within the same period, 64% in Denmark, 48% in Finland, 82% in Norway, and 78% in Sweden had received at least one type of preventive migraine medication. The proportion of individuals initiating erenumab as an add-on to another preventive migraine treatment varied by country (25% in Denmark, 39% in Finland, 31% in Norway, and 5% in Sweden). In Denmark and Sweden, >90% initiated erenumab in specialist care, most commonly neurology. One year after erenumab initiation, 50% of initiators in Denmark and Sweden, 38% in Finland, and 39% in Norway were still using the drug. Among those discontinuing erenumab, restarting erenumab within 1 year after discontinuation was relatively common (31% of discontinuers in Denmark, 41% in Finland, 47% in Norway, and 46% in Sweden). Number of individuals initiating erenumab on the same date botulinum toxin was dispensed was 24 Finland, 189 in Norway, and 127 in Sweden (these were not included in the total count of erenumab initiators).

Conclusions: Erenumab uptake and the proportion receiving erenumab as an add-on to another preventive treatment varied according to country. Considering population size, Norway and Finland had the greatest erenumab uptake. Likely reflecting guidelines, a large proportion of erenumab initiators had been treated with acute and preventive migraine medication within the 12 months preceding erenumab initiation. Concomitant use of erenumab and botulinum toxin was observed, although not described in current European guidelines.