Mirogabalin: a novel gabapentinoid or another false dawn?

PURPOSE OF REVIEW: Mirogabalin is a novel gabapentinoid medication for the treatment of neuropathic pain. The purpose of this review is to discuss current evidence for its use. Gabapentinoids are widely prescribed for neuropathic pain. Mirogabalin offers theoretical advantages over traditional gabapentinoids due to its specificity for the α2δ-1 subunit of voltage-gated calcium channels. It is theorised that this specificity may reduce adverse drug reactions by minimising binding to the α2δ-2 subunit which is responsible for many of the gabapentinoid side effects. RECENT FINDINGS: Mirogabalin's slower dissociation from the α2δ-1 compared with α2δ-2, and its higher potency may also impart an efficacy benefit over traditional gabapentinoids. These theoretical advantages of mirogabalin remain inconclusive in clinical practice, with mixed evidence regarding mirogabalin versus traditional gabapentinoids. Some studies suggest a reduced side effect profile yet, others fail to demonstrate significant differences. Regarding efficacy, mirogabalin may be superior to placebo for several neuropathic pain syndromes, but evidence of widespread benefit over traditional gabapentinoids is currently lacking. SUMMARY: Mirogabalin offers theoretical promise, but large, independent studies are required to further assess its performance versus traditional gabapentinoids.

Macrophage α7nAChR alleviates the inflammation of neonatal necrotizing enterocolitis through mTOR/NLRP3/IL-1ß pathway.

BACKGROUND: Neonatal necrotizing enterocolitis (NEC) is one of the most prevalent and severe intestinal emergencies in newborns. The inflammatory activation of macrophages is associated with the intestinal injury of NEC. The neuroimmune regulation mediated by α7 nicotinic acetylcholine receptor (α7nAChR) plays an important role in regulating macrophage activation and inflammation progression, but in NEC remains unclear. This study aims to explore the effect of macrophage α7nAChR on NEC. METHODS: Mice NEC model were conducted with high-osmolarity formula feeding, hypoxia, and cold stimulation. The α7nAChR agonist PNU-282987 and mTOR inhibitor rapamycin were treated by intraperitoneal injections in mice. The expression and distribution of macrophages, α7nAChR, and phospho-mammalian target of rapamycin (p-mTOR) in the intestines of NEC patients and mice was assessed using immunohistochemistry, immunofluorescence, and flow cytometry. The expression of NLRP3, activated caspase-1 and IL-1ß in mice intestines was detected by flow cytometry, western blot or ELISA. In vitro, the mouse RAW264.7 macrophage cell line was also cultured followed by various treatments. Expression of p-mTOR, NLRP3, activated caspase-1, and IL-1ß in macrophages was determined. RESULTS: Macrophages accumulated in the intestines and the expression of α7nAChR in the mucosal and submucosal layers of the intestines was increased in both the NEC patients and mice. The p-mTOR and CD68 were increased and co-localized in intestines of NEC patients. In vitro, α7nAChR agonist PNU-282987 significantly reduced the increase of NLRP3, activated caspase-1, and IL-1ß in macrophages. PNU-282987 also significantly reduced the increase of p-mTOR. The effect was blocked by AMPK inhibitor compound C. The expression of NLRP3, activated caspase-1, and IL-1ß was inhibited after mTOR inhibitor rapamycin treatment. In NEC model mice, PNU-282987 reduced the expression of p-mTOR, NLRP3, activated caspase-1, and IL-1ß in the intestine. Meanwhile, rapamycin significantly attenuated NLRP3 activation and the release of IL-1ß. Moreover, the proportion of intestinal macrophages and intestinal injury decreased after PNU-282987 treatment. CONCLUSION: Macrophage α7nAChR activation mitigates NLRP3 inflammasome activation by modulating mTOR phosphorylation, and subsequently alleviates intestinal inflammation and injury in NEC.

Mirogabalin as a Therapeutic Option for Neuropathic Pain Emerging Post-endodontic Treatment: A Two-Case Report.

INTRODUCTION: Occlusal and percussion pain may manifest occasionally following endodontic treatment, influencing retreatment decisions. Two cases of periapical neuropathic pain, classified as post-traumatic trigeminal neuropathic pain according to the International Classification of Orofacial Pain, are presented. Although mirogabalin is effective in managing neuropathic pain, there is a lack of clinical reports on its use for occasional post-traumatic trigeminal neuropathic pain after endodontic treatment. These cases highlight clinical symptoms and successful treatment with mirogabalin for post-traumatic trigeminal neuropathic pain after endodontic treatment, providing clinicians a "take-away" lesson for improving patient condition. METHODS: The patients, referred by their primary dentist due to postendodontic abnormal pain, found no relief with antibiotics or nonsteroidal anti-inflammatory drugs. Although no findings including swelling or periapical radiolucency were observed around the tooth, they experienced occlusal and percussion pain. Local anesthetic testing showed that the pain originated from the peripheral area around the tooth rather than from central sensitization. Dental radiography and cone-beam computed tomography revealed no abnormal findings. Root canal retreatment was performed by a specialist in endodontic treatment. Although endodontic retreatment drastically decreased visual analog scale pain score, pain persisted. Based on the International Classification of Orofacial Pain criteria, diseases other than post-traumatic trigeminal neuropathic pain were excluded. Mirogabalin (10 mg/d) was prescribed once daily before bedtime. RESULTS: Visual analog scale scores gradually and drastically decreased 2 weeks after mirogabalin therapy. Several months later, no recurrence of postendodontic pain was observed after tapering off and discontinuing mirogabalin. CONCLUSIONS: These findings suggest the possibility of a new treatment method for post-traumatic trigeminal neuropathic pain after endodontic treatment.

Efficacy of Mirogabalin for Taxane-associated Chemotherapy-induced Peripheral Neuropathy in Perioperative Chemotherapy for Early Breast Cancer.

BACKGROUND/AIM: Treatment with taxanes can result in chemotherapy-induced peripheral neuropathy (CIPN). We investigated the efficacy and safety of mirogabalin for the treatment of CIPN in patients who had been administered perioperative chemotherapy including taxane-based agents for breast cancer. PATIENTS AND METHODS: We retrospectively analyzed the case of 43 patients with early breast cancer who received a taxane as perioperative chemotherapy and were administered mirogabalin at the diagnosis of CIPN. RESULTS: Thirty-six patients (83.7%) had grade 1 CIPN and the other seven patients (16.3%) had grade 2 CIPN. The median mirogabalin dose was 10 mg (5-30 mg). CIPN improved from grade 1 to 0 in 12 patients (27.9%) and from grade 2 to 1 in one patient (2.3%); 13 (30.2%) patients thus had an objective therapeutic response. There were no cases in which chemotherapy was reduced or discontinued due to CIPN. Adverse events were evaluated by Common Terminology Criteria for Adverse Events and included five cases of dizziness (11.7%), three of somnolence (7.0%), and two of nausea (4.7%), all of which were grade ≤2. There were no cases of serious (grade ≥3) adverse effects. CONCLUSION: Mirogabalin may be effective and safe for treating CIPN of patients who receive a taxane in a perioperative breast cancer setting.

Modeling an evaluation of the efficacy of the novel neuroanalgesic drug mirogabalin for diabetic peripheral neuropathic pain and postherpetic neuralgia therapy.

Diabetic peripheral neuropathic pain (DPNP) and postherpetic neuralgia (PHN) are challenging and often intractable complex medical conditions, with a substantial impact on the quality of life. Mirogabalin, a novel voltage-gated Ca2+ channel α2δ ligand, was approved for the indication of DPNP and PHN. However, the time course of effects has not yet been clarified.We aimed to establish pharmacodynamic and placebo effect models of mirogabalin and pregabalin in DPNP and PHN, and to quantitatively compare the efficacy characteristics (maximum efficacy, onset time, and other pharmacodynamic parameters) and safety of mirogabalin and pregabalin. Public databases were comprehensively searched for randomized placebo-controlled clinical trials. A model-based meta-analysis (MBMA) was developed to describe the time course of drug efficacy and placebo effects. Adverse events were compared using a fixed-effects meta-analysis. Sixteen studies including 5,147 participants were eligible for this study. The placebo effect was relatively high and gradually increased with time, and it required at least eight weeks to reach a plateau. The pharmacodynamic model revealed that the maximum pure efficacy for mirogabalin and pregabalin was approximately -7.85 % and -8.86 %, respectively; the efficacy of mirogabalin to relieve DPNP and PHN was not superior to that of pregabalin, and both drugs had similar safety. While the rate constant of the onset rate of pregabalin was approximately thrice as high as that of mirogabalin. In addition, the baseline level of pain was an important factor affecting pregabalin efficacy. These findings are helpful in evaluating the clinical extension value of mirogabalin. They suggest that the high placebo effect and the baseline level of pain should be considered when grouping patients in future research and development of voltage-gated Ca2+ channel neuroanalgesic.

Alpha-7 Nicotinic Receptor Agonist Protects Mice Against Pulmonary Emphysema Induced by Elastase.

Pulmonary emphysema is a primary component of chronic obstructive pulmonary disease (COPD), a life-threatening disorder characterized by lung inflammation and restricted airflow, primarily resulting from the destruction of small airways and alveolar walls. Cumulative evidence suggests that nicotinic receptors, especially the α7 subtype (α7nAChR), is required for anti-inflammatory cholinergic responses. We postulated that the stimulation of α7nAChR could offer therapeutic benefits in the context of pulmonary emphysema. To investigate this, we assessed the potential protective effects of PNU-282987, a selective α7nAChR agonist, using an experimental emphysema model. Male mice (C57BL/6) were submitted to a nasal instillation of porcine pancreatic elastase (PPE) (50 µl, 0.667 IU) to induce emphysema. Treatment with PNU-282987 (2.0 mg/kg, ip) was performed pre and post-emphysema induction by measuring anti-inflammatory effects (inflammatory cells, cytokines) as well as anti-remodeling and anti-oxidant effects. Elastase-induced emphysema led to an increase in the number of α7nAChR-positive cells in the lungs. Notably, both groups treated with PNU-282987 (prior to and following emphysema induction) exhibited a significant decrease in the number of α7nAChR-positive cells. Furthermore, both groups treated with PNU-282987 demonstrated decreased levels of macrophages, IL-6, IL-1ß, collagen, and elastic fiber deposition. Additionally, both groups exhibited reduced STAT3 phosphorylation and lower levels of SOCS3. Of particular note, in the post-treated group, PNU-282987 successfully attenuated alveolar enlargement, decreased IL-17 and TNF-α levels, and reduced the recruitment of polymorphonuclear cells to the lung parenchyma. Significantly, it is worth noting that MLA, an antagonist of α7nAChR, counteracted the protective effects of PNU-282987 in relation to certain crucial inflammatory parameters. In summary, these findings unequivocally demonstrate the protective abilities of α7nAChR against elastase-induced emphysema, strongly supporting α7nAChR as a pivotal therapeutic target for ameliorating pulmonary emphysema.

Safety of mirogabalin and pregabalin in Japanese patients with neuropathic pain: a retrospective cohort study.

BACKGROUND: Few studies have compared the safety risks between the gabapentinoids, pregabalin, and mirogabalin in post-marketing clinical settings. We assessed reported events associated with gabapentinoid use in patients with neuropathic pain. RESEARCH DESIGN AND METHODS: We conducted a retrospective cohort study between September 2020 and December 2020 using the community pharmacies records in Japan. The pharmacists identified new vs. prevalent users of mirogabalin and pregabalin in September 2020 and reported data regarding baseline and adverse events to the Japan Pharmaceutical Association using web-based questionnaires. The incidence of events and hazard ratio (HR) were consequently compared. RESULTS: New users of mirogabalin and pregabalin were identified (n = 1,650 and 2,244; mean age (SD): 69 (15) and 68 (16) years; women: 59% and 56%, respectively). Although serious events were not reported, a marked difference in HRs of common adverse events, including somnolence (1.6), dizziness (1.3), nausea (2.8), edema (3.1), and acetaminophen (2.0)/antidepressant (2.4) addition, was observed. CONCLUSION: No new serious safety concerns were found for mirogabalin and pregabalin use in patients with neuropathic pain, although the HR of some events indicated increased risk among mirogabalin users. However, further studies are needed as estimates for events occurring in small numbers with wide confidence intervals.

Relationship between the dose titration and adherence of mirogabalin in patients with peripheral neuropathic pain depending on renal function: a nationwide electronic medical record database study.

BACKGROUND: Mirogabalin has been attracting attention for treating peripheral neuropathic pain. The package insert recommends that mirogabalin should be titrated depending on renal function. Here, we investigated the relationship between dose titration patterns and adherence, and persistence of mirogabalin treatment. RESEARCH DESIGN AND METHODS: Peripheral neuropathic pain patients who initiated mirogabalin between March 2020 and May 2021 were identified using an electronic medical record database. The dose titration pattern was described according to degrees of renal function. Regression analyses were performed to compare adherence and persistence between the patients with and without titration. RESULTS: Of the 4,138 identified patients, 1,696 (41.0%) titrated the dose within 45 days and were more adherent than those without titration (Adjusted odds ratio: 1.75, 95% CI 1.21, 2.54). Of the total 952 patients with renal function parameters, 229 (24.1%) titrated to the effective dose within 45 days and were less likely to discontinue than those without titration (Adjusted hazard ratio: 0.57, 95% CI 0.40, 0.81). CONCLUSION: Mirogabalin dose titration was associated with better adherence and persistence. It is important for mirogabalin treatment to determine the initial prescription dose based on renal function and subsequent dose titration according to the package insert. TRIAL REGISTRATION: UMIN000047313.

Prophylactic effects of hyperforin on anhedonia-like phenotype in chronic restrain stress model: A role of gut microbiota.

Anhedonia is the core symptom of depression, which largely reflects the therapeutic effect of depression. Hypericum perforatum is one of the most important antidepressant herb that has fewer side effects than traditional antidepressants. Considering the antibacterial effect of Hypericum perforatum, we verified whether this antidepressant activity was related to intestinal microbiomics. So we established anhedonia mouse model to explore the underlying treatment mechanism of hyperforin, the key antidepressant ingredient of Hypericum perforatum and to screen new psychobiotics based on hyperforin. It was found that hyperforin prevented anhedonia induced by chronic restraint stress in mice and altered the richness and evenness of bacteria populations compared with stressed mice. Metastat analysis showed that Akkermansia muciniphila and Muribaculum intestinale were the bacterial species obviously affected by hyperforin, and their abundance in hyperforin-treated group significantly increased. The results suggest that the effect of hyperforin on anhedonia may be partly assisted by Akkermansia muciniphila. These also indicate that Muribaculum intestinale may be another important intestinal bacteria involved in the pathogenesis of anhedonia symptom and depression.

Mirogabalin vs pregabalin for chemotherapy-induced peripheral neuropathy in pancreatic cancer patients.

BACKGROUND: The prognosis of pancreatic cancer (PC) has been improved by new chemotherapy regimens (combination of 5-fluorouracil, oxaliplatin, irinotecan, and leucovorin (FOLFIRINOX) or gemcitabine plus nab-paclitaxel (GnP)). Unfortunately, chemotherapy-induced peripheral neuropathy (CIPN) is a common adverse event of these two regimens. The efficacy of pregabalin for CIPN has been reported in previous studies. However, the efficacy of mirogabalin for CIPN remains unknown. Thus, in this study, we aimed to clarify which drug (mirogabalin or pregabalin) was more valuable for improving CIPN. METHODS: A total of 163 PC patients who underwent FOLFIRINOX or GnP between May 2014 and January 2021 were enrolled. Among them, 34 patients were diagnosed with CIPN. Thirteen patients were treated with mirogabalin (mirogabalin group), and twenty-one patients were treated with pregabalin (pregabalin group). Treatment efficacy was compared between the two groups. RESULTS: In both the mirogabalin group and the pregabalin group, the grade of patients with CIPN at 2, 4, and 6 weeks after the initiation of treatment showed significant improvement compared to the pretreatment grade. Notably, the rate of CIPN improvement was higher in the mirogabalin group than in the pregabalin group (2 weeks: 84.6% (11/13) vs 33.3% (7/21), P value = 0.005; 4 weeks, 6 weeks: 92.3% (12/13) vs 33.3% (7/21), P value = 0.001). CONCLUSIONS: Although both mirogabalin and pregabalin were effective at improving CIPN, mirogabalin might be a suitable first choice for CIPN in PC patients. TRIAL REGISTRATION: Not applicable.

Pretreatment with High Mobility Group Box-1 Monoclonal Antibody Prevents the Onset of Trigeminal Neuropathy in Mice with a Distal Infraorbital Nerve Chronic Constriction Injury.

Persistent pain following orofacial surgery is not uncommon. High mobility group box 1 (HMGB1), an alarmin, is released by peripheral immune cells following nerve injury and could be related to pain associated with trigeminal nerve injury. Distal infraorbital nerve chronic constriction injury (dIoN-CCI) evokes pain-related behaviors including increased facial grooming and hyper-responsiveness to acetone (cutaneous cooling) after dIoN-CCI surgery in mice. In addition, dIoN-CCI mice developed conditioned place preference to mirogabalin, suggesting increased neuropathic pain-related aversion. Treatment of the infraorbital nerve with neutralizing antibody HMGB1 (anti-HMGB1 nAb) before dIoN-CCI prevented both facial grooming and hyper-responsiveness to cooling. Pretreatment with anti-HMGB1 nAb also blocked immune cell activation associated with trigeminal nerve injury including the accumulation of macrophage around the injured IoN and increased microglia activation in the ipsilateral spinal trigeminal nucleus caudalis. The current findings demonstrated that blocking of HMGB1 prior to nerve injury prevents the onset of pain-related behaviors, possibly through blocking the activation of immune cells associated with the nerve injury, both within the CNS and on peripheral nerves. The current findings further suggest that blocking HMGB1 before tissue injury could be a novel strategy to prevent the induction of chronic pain following orofacial surgeries.

Ferula L. Plant Extracts and Dose-Dependent Activity of Natural Sesquiterpene Ferutinin: From Antioxidant Potential to Cytotoxic Effects.

The employment studies of natural extracts in the prevention and treatment of several diseases highlighted the role of different species of genus Ferula L., belonging to the Apiaceae family, dicotyledonous plants present in many temperate zones of our planet. Ferula communis L. is the main source of sesquiterpene ferutinin, a bioactive compound studied both in vitro and in vivo, because of different effects, such as phytoestrogenic, antioxidant, anti-inflammatory, but also antiproliferative and cytotoxic activity, performed in a dose-dependent and cell-dependent way. The present review will focus on the molecular mechanisms involved in the different activities of Ferutinin, starting from its antioxidant potential at low doses until its ionophoric property and the subsequent mitochondrial dysfunction induced through administration of high doses, which represent the key point of its anticancer action. Furthermore, we will summarize the data acquired from some experimental studies on different cell types and on several diseases. The results obtained showed an important antioxidant and phytoestrogenic regulation with lack of typical side effects related to estrogenic therapy. The preferential cell death induction for tumor cell lines suggests that ferutinin may have anti-neoplastic properties, and may be used as an antiproliferative and cytotoxic agent in an estrogen dependent and independent manner. Nevertheless, more data are needed to clearly understand the effect of ferutinin in animals before using it as a phytoestrogen or anticancer drug.

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.

[Analgesic Effects of Mirogabalin for Cancer Pain].

Mirogabalin is a novel drug for alleviating peripheral neuropathic pain, available since April 2019 in Japan. Since cancer pain was not included as an outcome in clinical trials for product approval, there have been no reports on its effectiveness or safety for treating cancer pain. The purpose of this study was to evaluate the effectiveness and safety of mirogabalin for patients with cancer pain. During the 5 months from April to August 2019, our palliative care team prescribed mirogabalin to 34 patients who had not achieved effective analgesia even after opioid titration. Effectiveness was defined as(1)reduction in persistent pain of 50% or more on the numeric rating scale(NRS); or(2)reduction in the frequency of rescue medicine of 50% or more for breakthrough pain. Based on this definition, the rate of effectiveness of mirogabalin was 88.2%. Two patients experienced mild side effects in the central nervous system. However, these effects did not result in discontinuation of the medication. The results of the study showed that mirogabalin can be used effectively and safely for cancer pain relief.

Pharmacological Inhibition of Soluble Epoxide Hydrolase as a New Therapy for Alzheimer's Disease.

The inhibition of the enzyme soluble epoxide hydrolase (sEH) has demonstrated clinical therapeutic effects in several peripheral inflammatory-related diseases, with 3 compounds in clinical trials. However, the role of this enzyme in the neuroinflammation process has been largely neglected. Herein, we disclose the pharmacological validation of sEH as a novel target for the treatment of Alzheimer's disease (AD). Evaluation of cognitive impairment and pathological hallmarks were used in 2 models of age-related cognitive decline and AD using 3 structurally different and potent sEH inhibitors as chemical probes. sEH is upregulated in brains from AD patients. Our findings supported the beneficial effects of central sEH inhibition, regarding reducing cognitive impairment, neuroinflammation, tau hyperphosphorylation pathology, and the number of amyloid plaques. This study suggests that inhibition of inflammation in the brain by targeting sEH is a relevant therapeutic strategy for AD.

Short-term outcomes of mirogabalin in patients with peripheral neuropathic pain: a retrospective study.

BACKGROUND: Mirogabalin, which is approved for the treatment of peripheral neuropathic pain in Japan, is a ligand for the α2δ subunit of voltage-gated calcium channels. Both pregabalin and mirogabalin act as nonselective ligands at the α2δ-1 and α2δ-2 subunits. Mirogabalin has a unique binding profile and long duration of action. Pregabalin has been reported to produce intolerable adverse effects in some patients. This study investigated outcomes associated with mirogabalin administration in patients with peripheral neuropathic pain who ceased treatment with pregabalin. METHODS: We retrospectively assessed peripheral neuropathic pain using the neuropathic pain screening questionnaire (NeP score) in 187 patients (58 men, 129 women) who were treated with mirogabalin. All patients had switched from pregabalin to mirogabalin due to lack of efficacy or adverse events. Differences in the treatment course (i.e., numeric rating scale (NRS) scores) were compared using one-way analysis of variance with Bonferroni post hoc tests. RESULTS: The mean age of the patients was 72.3 years (range, 30-94 years), and the mean duration of disease was 37 months (range, 3-252 months). After treatment with mirogabalin for 1 week, NRS scores significantly decreased compared with baseline and continued to decrease over time. After 8 weeks, NRS scores improved by ≥ 30% from baseline in 113 patients (69.3%). Twenty-four patients (12.8%) stopped mirogabalin treatment due to adverse events. Somnolence (26.7%), dizziness (12.3%), edema (5.9%), and weight gain (0.5%) were noted as adverse events of mirogabalin. CONCLUSIONS: The results of this investigation indicate that mirogabalin is safe and effective for reducing peripheral neuropathic pain.

Mirogabalin besylate in the treatment of neuropathic pain.

Neuropathic pain (NeP) is a global cause of suffering and debilitation leading to significant morbidity and reduced quality of life. New treatments are needed to address the growing prevalence of NeP and its impact on sleep, mood and functionality. Mirogabalin besylate (mirogabalin, Tarlige) is a gabapentinoid therapy developed by Daiichi Sankyo which is approved in Japan for the treatment of postherpetic neuralgia and painful diabetic peripheral neuropathy. Mirogabalin has a potent pain-modulating effect with a unique high affinity and prolonged dissociation rate for the a2delta-1 subunit of voltage-gated calcium (Ca2+) channels (VGCCs) on the dorsal root ganglion resulting in more sustained analgesia compared with traditional gabapentinoids. Additionally, mirogabalin has a superior adverse events (AEs) profile due to a rapid dissociation from the a2delta-2 subunit of VGCCs potentially implicated in central nervous system-specific AEs. The most common AEs for mirogabalin are dizziness (approximately 8-16%), somnolence (approximately 6-24%) and headache (approximately 6-14%), with a lower incidence of constipation, nausea, diarrhea, vomiting, edema, fatigue and weight gain. Postmarketing studies are required to evaluate its analgesic durability and efficacy when combined with other antineuropathic agents such as tricyclics, duloxetine and tramadol/tapentadol.

The mirogabalin ALDAY phase 3 program in pain associated with fibromyalgia: the lessons learned.

Aims: The main aim of this work was to identify and to share the lessons learned from the negative outcome of the mirogabalin ALDAY phase 3 clinical program in pain associated with fibromyalgia. These lessons are important to improve planning and design of future phase 3 programs in fibromyalgia.Methods: A systematic review from Cochrane Library, Medline, Embase, clinicaltrials.gov, pharmaceutical companies, and regulatory agencies' websites, was carried out starting from the development of gabapentin, the first α2δ ligand studied for the treatment of neuropathic pain and ending with the mirogabalin program.Results: Based on the outcome of the main fibromyalgia programs, several differences in design, primary endpoint choice, magnitude of placebo response, presence of an active comparator, and size of the entire clinical program were identified. This analysis focused on the negative primary results of the mirogabalin ALDAY program and found several contributing factors. Above all, the magnitude of placebo response and the unprecedented size of the program were identified. The number of study visits and procedures was also high and highly demanding on all subjects involved in ALDAY.Outcome: In terms of main lessons learned from ALDAY, the first was the need for a comprehensive patient-focused strategy to preliminarily identify the challenges of fibromyalgia based on patient perspective and study complexity. Second, there was a need for a harmonized, truly patient-centric, global regulatory guidance accepted by regulatory agencies. Third, ALDAY proved that a phase 2 proof of concept, dose ranging study is necessary before commencing any phase 3 program in fibromyalgia.

PNU-282987 Attenuates Intestinal Epithelial Barrier Dysfunction in LPS-Induced Endotoxemia.

PNU-282987, the α7 acetylcholine receptor(α7nAchR) agonist, has been repeatedly reported to play a key role in anti-inflammatory action of multiple disease. However, little is known about its effect on LPS-induced intestinal epithelial barrier dysfunction. This study investigated the protective effects and mechanisms of PNU-282987 on intestinal epithelial barrier dysfunction in lipopolysaccharide(LPS)-induced endotoxemic rats. Endotoxemia models were induced by intraperitoneal injection of 10 mg/kg LPS. In the endotoxemic group, results showed increases in ileum mucosal permeability, ultrastructural damage of tight junction and redistribution of zonula occludens-1, apoptosis of intestinal epithelial cells and caspase-3 activation. These changes were significantly improved after PNU-282987 administration(P < 0.05). Pretreatment with α-bungarotoxin before PNU-282987 administration reversed the effects of PNU-282987(P < 0.05). These results indicate that PNU-282987 exerts protective effects on intestinal epithelial barrier dysfunction in LPS-induced endotoxemic rats, and its mechanism may involve the improvement of zonula occludens-1 and inhibition of enterocyte apoptosis in an α7nAchR-dependent manner.

Cost-effectiveness of mirogabalin for the treatment of post-herpetic neuralgia in Taiwan.

Objectives: To assess the cost-effectiveness of mirogabalin versus no treatment or pregabalin in patients with post-herpetic neuralgia (PHN) from a third-party perspective in Taiwan.Methods: A Markov model, which was developed with 2-week cycles and 1-year time horizon from the Taiwanese National Health Insurance Administration perspective, consisted of three health states: "mild," "moderate," and "severe" pain. Average daily pain score (ADPS) was assessed at the end of each cycle. Patients either remained in, or transitioned from, their assigned health state to a different state according to their pain score changes. All patients entered the model in "moderate" (4 ≤ ADPS <7) or "severe" (7 ≤ ADPS ≤ 10) pain health states. Efficacy data was informed by the pivotal Phase III trial, or by a network meta-analysis (NMA). Utility values were obtained from published literature and cost data from Taiwanese clinical experts and the Taiwan National Health Insurance Administration, using 2018 New Taiwan dollar (NT$). Probabilistic analysis was conducted to test the robustness of base case results.Results: Head-to-head analysis showed mirogabalin 30 mg to be cost-effective versus placebo in PHN. The deterministic analysis estimated a quality-adjusted life years gain of 0.041 at an ICER of NT$11,231 (US$365) versus no treatment (ICER: NT$274,567 [US$8,900]). In the NMAs, mirogabalin was cost-effective compared to pregabalin 150 mg (ICER: NT$515,881 [US$16,720]) and 300 mg (ICER: NT$201,671 [US$6,535]). Mirogabalin 30 mg dominated pregabalin 600 mg. Results from sensitivity and scenario analyses confirmed these results.Conclusion: Mirogabalin 30 mg, a potent and selective α2δ ligand, is a cost-effective treatment option for PHN in Taiwan, with ICERs below the willingness-to-pay threshold.