Patient-Reported Outcomes of Mirogabalin in Patients with Postoperative Spinal Cord-Related Central Neuropathic Pain Inadequately Controlled with Conventional Gabapentinoids: A Retrospective Real-World Study

Objective: This single-center, observational study investigated the effectiveness and safety of switching to mirogabalin in patients with residual spinal cord-related central neuropathic pain that persisted despite conventional gabapentinoid therapy (gabapentin or pregabalin). Methods: Electronic medical records of 41 patients who switched from pregabalin or gabapentin to mirogabalin between November 2023 and June 2024 were retrospectively analyzed. Analgesic effectiveness was primarily assessed using the patient-reported percentage of pain reduction. Clinically meaningful and substantial pain reduction were defined as ≥ 30% and ≥ 50%, respectively. Safety was evaluated by assessing the incidence and severity of adverse events (AEs). Results: The mean baseline numerical rating scale score was 3.93 ± 1.75. Among the 41 patients included in the study, the interval between surgery and the first switch to mirogabalin was available for 35 patients. The median interval between surgery and switching to mirogabalin was 411 days (IQR, 88-743; range, 27-2091 days). Overall, 53.7% and 46.3% of patients achieved clinically meaningful (≥ 30%) and substantial (≥ 50%) pain reduction, respectively, after switching to mirogabalin. AEs were reported in 31.7% of patients, with the most common being somnolence (12.2%), dizziness (7.3%), and weight gain (7.3%). All reported AEs were mild to moderate in severity. Consequently, 19.5% and 22.0% of patients discontinued mirogabalin and resumed their previous medication because of insufficient efficacy and AEs, respectively. For the secondary analysis, patients were divided according to disease etiology (spinal cord tumor vs. non-tumoral myelopathy). Clinically meaningful pain reduction was achieved in 60.0% and 47.6% of patients, respectively, with no significant difference in responder rates between the two groups. Conclusion: Although the findings may overestimate treatment effectiveness because of the retrospective design and reliance on subjective patient assessment, switching to mirogabalin provided additional clinically meaningful pain relief in approximately half of the patients with persistent postoperative spinal cord-related central neuropathic pain that was inadequately controlled with conventional gabapentinoids. These findings suggest that mirogabalin may represent a promising alternative treatment option for patients with residual spinal cord-related central neuropathic pain who have limited therapeutic options.