AIM: Serum levels of Calcitonin Gene-Related Peptide (CGRP)-like immunoreactivity (CGRP-LI) in migraine patients before and after starting treatment with erenumab were measured to evaluate the association with clinical treatment response. METHODS: Blood samples were collected from the cubital fossa before (T0) and 2-4 weeks after (T1) starting treatment with erenumab. Clinical response was monitored using a daily headache e-diary. Serum levels of CGRP-LI, assessed using radioimmunoassay, were compared between T0 and T1, correcting for migraine reduction. In addition, for both T0 and T1, linear regression models were constructed using migraine reduction as outcome and serum CGRP-LI as independent variable, corrected for age, gender and monthly migraine days (MMD) at baseline. RESULTS: Serum CGRP-LI did not differ between T0 and T1 (p = 0.30). However, there was an interaction between time and reduction in MMD (p = 0.01). Absolute reduction in MMD in the third month after treatment with erenumab was associated with serum CGRP-LI at T1, 2-4 weeks after starting treatment with erenumab (p = 0.003), but not with serum CGRP-LI at T0 (p = 0.24). CONCLUSION: Lower serum CGRP-LI 2-4 weeks after starting treatment with erenumab was associated with a higher reduction in migraine days after three months of treatment. Although the underlying mechanisms remain to be determined, this suggests that changes in CGRP levels, shortly after starting erenumab, are important for its clinical effect.
Bibliographical noteFunding Information:
This study was supported by Vici grant 09150181910040 from the Dutch Research Council (AMVDB).
Gisela Terwindt reports consultancy support from Allergan/Abbvie, Lilly, Lundbeck, Novartis, and Teva, and independent support from Dutch Organization for Scientific Research, the Dutch Heart & Brain Foundations, IRRF and Dioraphte. Antoinette MaassenVanDenBrink reports consultancy or industry grant support from Novartis, Lilly and Teva, and independent support from the Dutch Research Council and the Dutch Heart & Brain Foundations. Simone de Vries Lentsch, Ingrid Garrelds and Jan Danser have nothing to disclose.
© 2022, The Author(s).