Long-Term Safety and Efficacy of Mirogabalin for Central Neuropathic Pain: A Multinational, Phase 3, 52-Week, Open-Label Study in Asia.

INTRODUCTION: Central neuropathic pain (CNeP) is difficult to treat and has diverse etiology, including spinal cord injury (CNePSCI), Parkinson's disease (CNePPD), and central post-stroke pain (CPSP). The safety and efficacy of mirogabalin have been demonstrated in short-term trials, including patients with CNePSCI. The objective of our study was to confirm the safety/efficacy of mirogabalin in patients with CNePPD and CPSP, and obtain long-term data for CNePSCI. METHODS: This 52-week, open-label extension of a previous randomized controlled study was conducted across Japan, Korea, and Taiwan. Patients with CNePSCI, CNePPD, or CPSP received twice daily (BID) 5-10 mg mirogabalin for a 4-week titration period, after which the dosage was maintained for 47 weeks at a maximum of 15 mg BID, followed by a 1-week taper period receiving the same dose but only administered once daily. The primary endpoint was safety, assessed primarily by incidence and severity of treatment-emergent adverse events (TEAEs). Efficacy was assessed in a post hoc analysis of data obtained by the short-form McGill Pain Questionnaire (SF-MPQ). RESULTS: Of the 210 patients enrolled, 106, 94, and 10 had CNePSCI, CPSP, and CNePPD, respectively. The mean overall age of patients was 62.9 years, and most patients were male and of Japanese ethnicity. TEAEs occurred in 84.8% of patients, the most common being somnolence (16.7%), peripheral edema (12.4%), edema (11.4%), nasopharyngitis (11.0%), and dizziness (7.6%). Most TEAEs were mild. Severe and serious TEAEs occurred in 6.2% and 13.3% of patients, respectively. All patient groups experienced reductions in SF-MPQ visual analog scores for pain: mean ± standard deviation changes from baseline at week 52 were -2.3 ± 21.13 mm (CNePSCI), -17.0 ± 24.99 mm (CPSP), and -17.1 ± 35.32 mm (CNePPD). CONCLUSION: Mirogabalin was generally safe, well tolerated, and effective for treatment of CNeP in this long-term study. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT03901352.

Mirogabalin for Central Neuropathic Pain After Spinal Cord Injury: A Randomized, Double-Blind, Placebo-Controlled, Phase 3 Study in Asia.

BACKGROUND AND OBJECTIVES: Patients with spinal cord injury (SCI) commonly experience central neuropathic pain (CNeP), which is challenging to treat. Mirogabalin is effective for peripheral neuropathic pain, but evidence for CNeP is lacking. METHODS: This randomized, double-blind, placebo-controlled, phase 3 study investigated mirogabalin efficacy and safety for the treatment of CNeP in patients with traumatic SCI. Adult patients from 120 sites throughout Japan, Korea, and Taiwan were randomized (1:1) to receive placebo or mirogabalin (5 mg twice daily [BID] for 1 week, 10 mg BID for 1 week, and 10 or 15 mg BID for 12 weeks). Patients with moderate renal impairment received half the dosage. The primary efficacy endpoint was change from baseline in the weekly average daily pain score (ADPS) at week 14. The secondary endpoints included ADPS responder rates, the Short-Form McGill Pain Questionnaire (SF-MPQ), average daily sleep interference score (ADSIS), and Neuropathic Pain Symptom Inventory (NPSI). Adverse events were monitored for safety. RESULTS: Each treatment group comprised 150 patients. Mirogabalin elicited a statistical and clinically relevant improvement in change from baseline in the weekly ADPS at week 14 (least-squares mean difference [95% CI] vs placebo -0.71 [-1.08 to -0.34], p = 0.0001). Responder rates at week 14 were higher for mirogabalin than those for placebo (odds ratio [95% CI] 1.91 [1.11-3.27] for the ≥30% responder rate; 2.52 [1.11-5.71] for the ≥50% responder rate). Statistical improvements (i.e., least-squares mean difference [95% CI] vs placebo) were also observed in the SF-MPQ (-2.4 [-3.8 to -1.1]), ADSIS -0.71 (-1.04 to -0.38), and NPSI -7.7 (-11.1 to -4.4) scores. Most treatment-emergent adverse events were mild; no serious adverse drug reactions were reported. DISCUSSION: Mirogabalin elicited clinically relevant decreases in pain and was well tolerated, suggesting that mirogabalin is a promising treatment for patients with CNeP due to SCI. TRIAL REGISTRATION INFORMATION: ClinicalTrials.gov (NCT03901352); first submitted April 3, 2019; first patient enrolled March 14, 2019; available at clinicaltrials.gov/ct2/show/NCT03901352. CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that in adult patients with CNeP due to traumatic SCI, mirogabalin, 10 or 15 mg BID, effectively improves weekly ADPS at week 14.

Safety and Efficacy of Mirogabalin for Peripheral Neuropathic Pain: Pooled Analysis of Two Pivotal Phase III Studies.

PURPOSE: Mirogabalin besylate has been approved in several countries to treat peripheral neuropathic pain. This pooled analysis, using data from the two pivotal Phase III studies in Asian patients with diabetic peripheral neuropathic pain and post-herpetic neuralgia, aimed to provide clinicians with more detailed and precise information relating to mirogabalin's safety and efficacy. METHODS: Data were pooled from 2 multicenter, double-blind, placebo-controlled, parallel-group, 14-week treatment studies of mirogabalin conducted at ∼350 study sites (Japan, South Korea, Taiwan, Singapore, Malaysia, and Thailand). Eligible patients in both studies were randomized in a 2:1:1:1 ratio, stratified according to a baseline average daily pain score (ADPS) of <6 or ≥6, to placebo, mirogabalin 15-mg once daily (QD), mirogabalin 10-mg twice daily (BID), or mirogabalin 15-mg BID treatment groups. Safety was assessed based on treatment-emergent adverse events identified from the adverse events collected throughout both studies. The primary efficacy end point of both studies was the change from baseline in ADPS at week 14. FINDINGS: In total, 1587 patients (824 with diabetic peripheral neuropathic pain; 763 with post-herpetic neuralgia) who received at least 1 dose of study drug were analyzed (633 received placebo, 954 treated with mirogabalin). Treatment-emergent adverse events included somnolence (3.8%, 10.8%, 14.5%, and 19.1%) and dizziness (2.7%, 5.7%, 9.1%, and 13.1%) in patients receiving placebo, mirogabalin 15 mg QD, mirogabalin 10 mg BID, and mirogabalin 15 mg BID, respectively. In patients treated with mirogabalin 15 mg QD, 2 (0.6%) of 316 patients discontinued due to somnolence. In the mirogabalin 10-mg BID group, somnolence, edema, and peripheral edema each resulted in 3 (0.9%) of 318 patient discontinuations. In the mirogabalin 15-mg BID group, 6 (1.9%) of 320 patients discontinued due to dizziness and 3 (0.9%) due to somnolence. At week 14, mirogabalin 10 mg BID and 15 mg BID statistically significantly improved ADPS versus placebo, with least squares mean changes (95% CI) of -0.31 (-0.55, -0.08) and -0.63 (-0.86, -0.40). Post hoc analysis showed a statistically significant difference 2 days after administration in the mirogabalin 10-mg and 15-mg BID groups compared with placebo. Female sex, age ≥65 years, and baseline weight <60 kg may influence the safety of mirogabalin, particularly regarding the incidence of somnolence and dizziness, but had no notable impact on efficacy. ClinicalTrials.gov identifiers: NCT02318706 and NCT02318719. IMPLICATIONS: This pooled analysis showed that mirogabalin was efficacious and well-tolerated by Asian patients with peripheral neuropathic pain.

Long-term safety and efficacy of mirogabalin in Asian patients with postherpetic neuralgia: Results from an open-label extension of a multicenter randomized, double-blind, placebo-controlled trial.

OBJECTIVE: Postherpetic neuralgia (PHN) is a condition that results from nerve dysfunction following an episode of acute herpes zoster (shingles). Mirogabalin is a novel, selective oral α2δ ligand that demonstrated safety and efficacy in a multicenter, randomized, double-blind, placebo-controlled 14-week study in Asian patients with PHN. This 52-week, open-label extension study investigated the long-term safety and efficacy of flexible-dosage mirogabalin in Asian patients with PHN. METHODS: This open-label extension study enrolled patients who completed the placebo-controlled study. Patients started with a dose of 5 mg mirogabalin twice daily (BID), which was followed by a flexible dose of 10 or 15 mg BID. During the study, patients assessed their pain using the Short-Form McGill Pain Questionnaire (SF-MPQ). Adverse events were monitored throughout the study. RESULTS: Of 239 enrolled patients, 184 (77.0%) completed the study and 185 patients (77.4%) received the 15 mg BID dose most during the treatment duration. Most treatment-emergent adverse events (TEAEs) were mild or moderate. The most common TEAEs were nasopharyngitis, somnolence, dizziness, weight increased, and edema. All SF-MPQ scales decreased from baseline to week 52. CONCLUSIONS: This study showed the safety and stable pain management of a long-term flexible dosing regimen of mirogabalin 10 or 15 mg twice daily for 52 weeks in patients with PHN. CLINICAL TRIAL REGISTERED AT CLINICALTRIALS.GOV:: NCT02318719. SUMMARY FOR TABLE OF CONTENTS: Mirogabalin-a novel α2δ oral ligand-was shown to be effective and well tolerated for treating postherpetic neuralgia (PHN) in an Asian multicenter, randomized, double-blind, placebo-controlled, 14-week study. This open-label, 52-week study was conducted as an extension of the double-blind study to demonstrate long-term safety and efficacy of mirogabalin.

Mirogabalin for the management of postherpetic neuralgia: a randomized, double-blind, placebo-controlled phase 3 study in Asian patients.

This study investigated the safety and efficacy of mirogabalin, a novel, potent, selective ligand of the α2δ subunit of voltage-dependent Ca channels, for the treatment of postherpetic neuralgia (PHN). In this multicenter, double-blind, placebo-controlled phase 3 study, Asian patients ≥20 years with PHN were randomized 2:1:1:1 to placebo or mirogabalin 15, 20, or 30 mg/day for up to 14 weeks (NCT02318719). The primary efficacy endpoint was the change from baseline in average daily pain score at week 14, defined as a weekly average of daily pain (0 = "no pain" to 10 = "worst possible pain," for the last 24 hours). Of 765 patients randomized, 763 received ≥ 1 dose of the study drug and were included in the analysis; 303, 152, 153, and 155 received placebo, mirogabalin 15, 20, or 30 mg/day, respectively. A total of 671 (87.7%) patients completed the study. At week 14, the difference in average daily pain score least squares mean vs placebo was -0.41, -0.47, and -0.77, respectively; all mirogabalin groups showed statistical significance. The most common treatment-emergent adverse events were somnolence, nasopharyngitis, dizziness, weight increase, and edema, and all of them were mild or moderate in severity. Mirogabalin was superior to placebo in all groups for relieving PHN and appeared well tolerated.