# Predictors of Response to Treatment With Anti-calcitonin Gene-Related Peptide (CGRP) Antibodies in Real-World Patients With Episodic Migraine: A Two- and Four-Month Prospective Study

## TL;DR

This study identifies factors like normal BMI and headache characteristics that predict better response to anti-CGRP antibody treatment in migraine patients.

## Contribution

The study identifies clinical predictors of sustained response to anti-CGRP antibodies in real-world episodic migraine patients.

## Key findings

- Migraine frequency significantly decreased from baseline to two and four months after anti-CGRP antibody treatment.
- Patients with normal BMI showed a greater reduction in migraine frequency compared to those who were overweight.
- Unilateral headaches and severe osmophobia were also associated with significant reductions in migraine days.

## Abstract

Background: Monoclonal antibodies (mAbs) for anti-calcitonin gene-related peptide (CGRP) have emerged as an effective and well-tolerated option for alleviating migraine burden and improving patients’ quality of life. There is limited understanding of the specific clinical and biological predictors that forecast sustained response to anti-CGRP antibodies in real-world episodic migraine patients. This study was designed to estimate the proportion and potential predictors of response (≥50% response rate) at two months and four months in real-world patients with episodic migraine who received this therapy as their only preventive treatment.

Method: This is an open prospective study carried out in consecutive episodic migraine patients (International Classification of Headache Disorders (ICHD)-3) with six to 10 monthly headache days (MHD), seen for the first time from January 2023 to May 2024 in a tertiary center, to whom a monoclonal antibody anti-CGRP (fremanezumab or galcanezumab) was prescribed as the only preventive treatment. Sixty-three patients fulfilled the eligibility criteria. The patients were evaluated in long-lasting initial consultations, and follow-up visits were carried out after two and four months. Data was collected using a semi-structured proforma and a detailed headache diary.

Results: There was a significant reduction in the migraine frequency as measured by MHD from baseline to two months and four months after intervention (P=0.000, 8.85±1.17 days at baseline to 6.39±3.60 at two months and 6.35±3.25 at four months). The reduction in MHD was significantly higher among those who had a normal BMI as compared to the participants who were overweight (P=0.000) and those who had unilateral headaches (P=0.013) and severe osmophobia during attacks (P=0.035). Approximately 39.7% (n=25) of participants achieved a ≥50% reduction in MHD at both two and four months.

Conclusion: Normal BMI was found to be significantly associated with a reduction in migraine frequency of >50%, whereas normal BMI, unilateral headache, and severe osmophobia were significantly associated with a mean MHD reduction. Further controlled studies with several other factors predicting response to anti-CGRP mAbs are warranted.