Pregabalin, the lidocaine plaster and duloxetine in patients with refractory neuropathic pain: a systematic review

Abstract Background Patients frequently fail to receive adequate pain relief from, or are intolerant of, first-line therapies prescribed for neuropathic pain (NeP). This refractory chronic pain causes psychological distress and impacts patient quality of life. Published literature for treatment in refractory patients is sparse and often published as conference abstracts only. The aim of this study was to identify published data for three pharmacological treatments: pregabalin, lidocaine plaster, and duloxetine, which are typically used at 2nd line or later in UK patients with neuropathic pain. Methods A systematic review of the literature databases MEDLINE, EMBASE and CCTR was carried out and supplemented with extensive conference and grey literature searching. Studies of any design (except single patient case studies) that enrolled adult patients with refractory NeP were included in the review and qualitatively assessed. Results Seventeen studies were included in the review: nine of pregabalin, seven of the lidocaine plaster, and one of duloxetine. No head-to-head studies of these treatments were identified. Only six studies included treatments within UK licensed indications and dose ranges. Reported efficacy outcomes were not consistent between studies. Pain scores were most commonly assessed in studies including pregabalin; trials of pregabalin and the lidocaine plaster reported the proportion of responders. Significant improvements in the total, sensory and affective scores of the Short-form McGill Pain Questionnaire, and in function interference, sleep interference and pain associated distress, were associated with pregabalin treatment; limited or no quality of life data were available for the other two interventions. Limitations to the review are the small number of included studies, which are generally small, of poor quality and heterogeneous in patient population and study design. Conclusions Little evidence is available relevant to the treatment of refractory neuropathic pain despite the clinical need. There is a notable lack of high-quality comparative studies. It is evident that there is a need for future, high quality trials, particularly "gold-standard" RCTs in this refractory patient population.</p

Systematic literature review and network meta-analysis of cladribine tablets versus alternative disease-modifying treatments for relapsing–remitting multiple sclerosis

<p><b>Objective:</b> To assess the comparative efficacy and safety of cladribine tablets versus alternative disease modifying treatments (DMTs) in patients with active relapsing–remitting multiple sclerosis (RRMS), and in a subgroup with high disease activity (HRA + DAT), using systematic literature review (SLR) and network meta-analysis (NMA).</p> <p><b>Methods:</b> MEDLINE, Embase, MEDLINE In-Process and CENTRAL databases were systematically searched to identify English-language publications of relevant studies of approved DMTs for RRMS. Searches were conducted from database inception to January 2017. Conference websites and trial registries were also searched. NMA considered the effects of DMTs on annualized relapse rate (ARR), confirmed disease progression (CDP), no evidence of disease activity (NEDA) and safety.</p> <p><b>Results:</b> Of 10,825 articles retrieved and screened, 44 studies assessing 12 DMTs contributed to the NMA. In patients with active RRMS, cladribine tablets were associated with a significant 58% reduction in ARR versus placebo (<i>p</i> < .05); cladribine tablets were similar or significantly better than other DMT regimens and ranked fourth among DMTs, behind alemtuzumab, natalizumab and ocrelizumab. For CDP for 6 months and NEDA, improvements with cladribine tablets were significantly greater than those of placebo (<i>p</i> < .05), with no comparator DMT demonstrating significantly better results. Similar findings were reported in the HRA + DAT population. Overall adverse event risk for cladribine tablets did not differ significantly from that of placebo and most alternative DMTs.</p> <p><b>Conclusion:</b> In this first NMA to consider cladribine tablets, ocrelizumab and daclizumab for treatment of RRMS, cladribine tablets are a comparatively effective and safe alternative to other DMTs in both active RRMS and HRA + DAT populations.</p