Triptan Consumption Before and After the Initiation of an Anti-CGRP mAb: A Descriptive Drug Utilization Study in Tuscany Region, Italy

Background: Numerous clinical trials showed the efficacy of calcitonin gene-related peptide (CGRP) monoclonal antibodies (mAbs) in migraine prevention by measuring the reduction in the absolute number of days of migraine or use of acute migraine medications. However, to date, the impact of anti-CGRP therapy on the use of migraine-specific drugs like triptans in the real-world clinical practice has been poorly investigated.

Objectives: To describe triptan consumption before and after initiation of an anti-CGRP mAb treatment.

Methods: The population-based regional administrative database of Tuscany, Italy, was used. Subjects with ≥1 dispensing of erenumab (ERE), galcanezumab (GAL) and fremanezumab (FRE) (ATC N02CD*) reimbursed by the National Health Service between April 1, 2019 and June 30, 2021 were identified. The date of the first dispensing was the cohort entry date (CED). New users (NU) were subjects with no anti-CGRP mAb dispensing before CED. NU with < 2 triptan dispensings during the six months prior to CED, i.e. baseline, were excluded. NU were followed until 30 September 2021, switch, discontinuation, death or end of data availability. The mean monthly dosage units per patient was used to measure triptan consumption among patients still in the study at the end of each follow up time-window, i.e. 0-3, 3-6, 6-9, 9-12 and 12-15 months. The difference (Δ) between triptan consumption observed in each follow up time-window and that observed at baseline in the same users' population was reported. Results were stratified by active substance, sex and age band. Wilcoxon's test for paired data was used to assess statistical significance (p≤0.05).

Results: A total of 277 NU of anti-CGRP mAbs (ERE=128; GAL=109; FRE=40) were included in the study cohort, of which 214 (77%) were female. Mean age was 49.7 years. In the overall study population, the observed values of Δ at 3/6/9/12 months were -4.7/-6.1/-6.3/-5.8, respectively (p≤0.05). Among ERE users the observed Δ values were -3/-5.4/-5.6/-4.7 (p≤0.05) while among GAL users -6.8/-6.7/-8.2/-8.7 (p≤0.05). Among female NU the observed Δ values were -4.5/-6.3/-6.6/-6.1/ (p≤0.05) while among NU aged 40-64 years -5.1/-6.2/-6.3/-5.7 (p≤0.05). No statistically significant results were obtained at 15 months in any of the cohort strata.

Conclusions: Compared to baseline, a significant reduction in triptans consumption was observed up to 12 months following the initiation of an anti-CGRP mAb. The observed lack of significance at 15 months is likely due to the recommended therapeutic suspension, other than the small sample size. Further studies are needed to compare the effectiveness of the three anti-CGRP mAbs and investigate patients' characteristics associated with increased effectiveness of these drugs.