Long‐term safety and efficacy of mirogabalin in Asian patients with diabetic peripheral neuropathic pain

Aims/Introduction Diabetic peripheral neuropathic pain (DPNP) affects the functionality, mood and sleep patterns of patients with diabetes. Mirogabalin, an α 2 δ ligand with a slower dissociation for α 2 δ‐1 versus α 2 δ‐2 subunits, showed efficacy and safety in a randomized, double‐blind, placebo‐controlled, 14‐week study in Asian patients with DPNP. This open‐label extension study evaluated the long‐term safety and efficacy of mirogabalin in Asian patients with DPNP. Material and Methods This 52‐week open‐label extension study was carried out in Japan, Korea and Taiwan in patients with DPNP. Patients received mirogabalin, initiated at 5 mg twice daily and increased to a flexible maintenance dosage of 10 or 15 mg twice daily. Adverse events were monitored throughout the study. Patients provided a self‐assessment of pain using the Short‐Form McGill Pain Questionnaire. Results Of the 214 patients who entered the study, 172 (80.4%) completed the extension study. Of 172 patients who completed the study, 149 received the highest dosage of mirogabalin (15 mg twice daily). The most common treatment‐emergent adverse events were nasopharyngitis, diabetic retinopathy, peripheral edema, somnolence, diarrhea, increased weight and dizziness. Most treatment‐emergent adverse events were mild or moderate in severity. The incidence of treatment‐emergent adverse events leading to treatment discontinuation was 13.1%. The visual analog scale and all other Short‐Form McGill Pain Questionnaire subscales (sensory score, affective score, total score and present pain intensity) generally decreased over time from baseline until week 52. Conclusions This extension study showed the safety and efficacy of a long‐term flexible dosing regimen of mirogabalin 10 or 15 mg twice daily in patients with DPNP.