In a groundbreaking development for vestibular migraine treatment, galcanezumab (Emgality) has demonstrated significant therapeutic efficacy in the first-ever randomized, controlled trial testing a CGRP-blocking medication for this condition. The INVESTMENT study, conducted at UCSF Health, provides compelling evidence for a new treatment approach for patients suffering from this debilitating condition.
Clinical Trial Results and Patient Outcomes
The double-blind, placebo-controlled study enrolled 40 patients, randomized 1:1 to receive either galcanezumab or placebo over a three-month treatment period. Patients received an initial 240 mg dose followed by 120 mg monthly doses. The study population predominantly consisted of female participants (75%) with confirmed vestibular migraine diagnosis according to Barany Society criteria (88%).
Treatment with galcanezumab yielded impressive results across multiple outcome measures. Patients receiving the active treatment experienced a dramatic reduction in definite dizzy days (DDDs), decreasing from 17.9 to 6.6 by month 4 (P = .026), while the placebo group showed a more modest reduction from 18.0 to 12.5 days.
Significant Improvements in Quality of Life Measures
The Dizziness Handicap Inventory (DHI) scores revealed substantial improvements in the treatment group, with patients experiencing a reduction of 22.0 points compared to 8.3 points in the placebo group (P = .018). This difference demonstrated a large effect size (Cohen's d = .98), indicating clinically meaningful improvement.
The Vestibular Migraine Patient Assessment Tool and Handicap Inventory (VM-PATHI) scores also showed promising results, with the galcanezumab group experiencing a 14.8-point reduction compared to a 5.1-point drop in the placebo group. While this achieved statistical significance on one-tailed t-test (P = .044), it narrowly missed significance on two-tailed testing (P = .087).
Patient-Reported Outcomes and Treatment Effectiveness
Patient satisfaction with the treatment was notably higher in the galcanezumab group, with 71% of treated patients reporting moderate or greater treatment effects, compared to only 24% in the placebo group (P = .004). On a scale from 0 to 4, the galcanezumab group reported a mean effectiveness score of 2.1, while the placebo group averaged 1.0.
Study Implications and Future Directions
Dr. Jeffrey D. Sharon, assistant professor at UCSF Health and study lead, emphasized the significance of these findings: "This study adds to a body of evidence that VM is just another form of migraine and that the pathophysiology involves CGRP." While acknowledging the study's limitations, including its early termination and single-center design, the consistent positive results across multiple outcome measures strongly support the potential of CGRP blockade in treating vestibular migraine.
The findings represent a significant step forward in understanding and treating vestibular migraine, though larger, multi-center trials are needed to fully establish the role of CGRP-blocking medications in clinical practice. The success of this pilot study opens new avenues for research and treatment options for patients suffering from this common yet often challenging condition.
