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.

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.