Pregabalin for the treatment of painful diabetic peripheral neuropathy: a double-blind, placebo-controlled trial

A randomized, double-blind, placebo-controlled, parallel-group, multicenter, 8-week trial (with subsequent open-label phase) evaluated the effectiveness of pregabalin in alleviating pain associated with diabetic peripheral neuropathy (DPN). For enrollment, patients must have had at baseline: 1- to 5-year history of DPN pain; pain score ≥40 mm (Short-Form McGill Pain Questionnaire [SF-MPQ] visual analogue scale); average daily pain score of ≥4 (11-point numerical pain rating scale [0=no pain, 10=worst possible pain]). One hundred forty-six (146) patients were randomized to receive placebo (n=70) or pregabalin 300 mg/day (n=76). Primary efficacy measure was endpoint mean pain score from daily patient diaries (11-point numerical pain rating scale). Secondary measures included SF-MPQ scores; sleep interference scores; Patient and Clinical Global Impression of Change (PGIC and CGIC); Short Form-36 (SF-36) Health Survey scores; and Profile of Mood States (POMS) scores. Safety assessment included incidence and intensity of adverse events, physical and neurological examinations, and laboratory evaluations. Pregabalin produced significant improvements versus placebo for mean pain scores (P<0.0001); mean sleep interference scores (P<0.0001); total SF-MPQ score (P<0.01); SF-36 Bodily Pain subscale (P<0.03); PGIC (P=0.001); and Total Mood Disturbance and Tension–Anxiety components of POMS (P<0.03). Pain relief and improved sleep began during week 1 and remained significant throughout the study (P<0.01). Pregabalin was well tolerated despite a greater incidence of dizziness and somnolence than placebo. Most adverse events were mild to moderate and did not result in withdrawal. Pregabalin was safe and effective in decreasing pain associated with DPN, and also improved mood, sleep disturbance, and quality of life.     

Long-term migraine prevention with topiramate: open-label extension of pivotal trials

OBJECTIVE: To demonstrate that topiramate is an effective and generally well-tolerated migraine preventive therapy when used for up to 14 months. BACKGROUND: Topiramate 100 and 200 mg/d significantly reduced mean monthly migraine frequency during 2 large, 26-week, randomized, placebo-controlled trials. Only a small number of clinical trials have examined the long-term (> or =1 year) effectiveness and safety of migraine preventive therapies. METHODS: Five hundred sixty-seven patients with an established history of migraine with or without aura were enrolled in this 8-month, open-label extension of 2 large (49 US and 52 US and Canadian medical centers), randomized, double-blind, placebo-controlled, parallel group, 26-week trials of identical design. To be eligible for the open-label extension, patients were required to have either completed the double-blind phase of the 2 pivotal migraine prevention trials or withdrew after 4 weeks due to lack of efficacy. All eligible patients, regardless of type or dose of study medication (topiramate or placebo) received in the double-blind phase, were titrated to a clinically effective dose of open-label topiramate based on physician judgment of patient response. Efficacy of topiramate was measured as the change in mean monthly migraine frequency. RESULTS: The mean topiramate dose during the open-label extension phase was 124.7 mg/d and 150.3 mg/d for patients on placebo (n = 159) or topiramate (n = 408), respectively, during the double-blind phase (N = 567, 91% female, mean age 39.4 years). Patients on topiramate for up to 14 months had 2.2 +/- 2.4 (mean +/- SD) migraines per month after completion of the open-label extension phase (3.4 +/- 2.6 at double-blind endpoint). Patients on topiramate during the open-label extension phase only (placebo during the double-blind phase) had 3.0 +/- 2.9 migraines per month at open-label extension endpoint (4.9 +/- 3.0 migraines per month at double-blind endpoint). Discontinuation rates due to adverse events during the double-blind phase were 22.2% for patients on topiramate and 11.0% for patients on placebo. Discontinuation rates due to adverse events during the open-label extension phase were 8.6% for those patients who had already received topiramate during the double-blind phase and 20.9% for those patients who had previously received placebo. CONCLUSIONS: Patients receiving topiramate experienced a sustained reduction in migraine frequency for up to 14 months. The effectiveness and safety of topiramate was consistent with that observed during 2 26-week pivotal trials.     

Nabiximols for opioid-treated cancer patients with poorly-controlled chronic pain: a randomized, placebo-controlled, graded-dose trial

Patients with advanced cancer who have pain that responds poorly to opioid therapy pose a clinical challenge. Nabiximols (Nabiximols is the U.S. Adopted Name [USAN] for Sativex [GW Pharma Ltd, Wiltshire, U.K.], which does not yet have an INN), a novel cannabinoid formulation, is undergoing investigation as add-on therapy for this population. In a randomized, double-blind, placebo-controlled, graded-dose study, patients with advanced cancer and opioid-refractory pain received placebo or nabiximols at a low dose (1-4 sprays/day), medium dose (6-10 sprays/day), or high dose (11-16 sprays/day). Average pain, worst pain and sleep disruption were measured daily during 5 weeks of treatment; other questionnaires measured quality of life and mood. A total of 360 patients were randomized; 263 completed. There were no baseline differences across groups. The 30% responder rate primary analysis was not significant for nabiximols versus placebo (overall P = .59). A secondary continuous responder analysis of average daily pain from baseline to end of study demonstrated that the proportion of patients reporting analgesia was greater for nabiximols than placebo overall (P = .035), and specifically in the low-dose (P = .008) and medium-dose (P = .039) groups. In the low-dose group, results were similar for mean average pain (P = .006), mean worst pain (P = .011), and mean sleep disruption (P = .003). Other questionnaires showed no significant group differences. Adverse events were dose-related and only the high-dose group compared unfavorably with placebo. This study supports the efficacy and safety of nabiximols at the 2 lower-dose levels and provides important dose information for future trials. PERSPECTIVE: Nabiximols, a novel cannabinoid formulation, may be a useful add-on analgesic for patients with opioid-refractory cancer pain. A randomized, double-blind, placebo-controlled, graded-dose study demonstrated efficacy and safety at low and medium doses.     

Efficacy and safety of topiramate for the treatment of chronic migraine: a randomized, double-blind, placebo-controlled trial

OBJECTIVE: To evaluate the efficacy and safety of topiramate (100 mg/day) compared with placebo for the treatment of chronic migraine. METHODS: This was a randomized, placebo-controlled, parallel-group, multicenter study consisting of 16 weeks of double-blind treatment. Subjects aged 18 to 65 years with 15 or more headache days per month, at least half of which were migraine/migrainous headaches, were randomized 1:1 to either topiramate 100 mg/day or placebo. An initial dose of topiramate 25 mg/day (or placebo) was titrated upward in weekly increments of 25 mg/day to a maximum of 100 mg/day (or to the maximum tolerated dose). Concomitant preventive migraine treatment was not allowed, and acute headache medication use was not to exceed 4 days per week during the double-blind maintenance period. The primary efficacy endpoint was the change from baseline in the mean monthly number of migraine/migrainous days; the change in the mean monthly number of migraine days also was analyzed. A fixed sequence approach (ie, gatekeeper approach) using analysis of covariance was used to analyze the efficacy endpoints. Assessments of safety and tolerability included physical and neurologic examinations, clinical laboratory parameters, and spontaneous reports of clinical adverse events. RESULTS: The intent-to-treat population included 306 (topiramate, n = 153; placebo, n = 153) of 328 randomized subjects who provided at least 1 efficacy assessment; 55.8% of the topiramate group and 55.2% on placebo were trial completers. The mean final topiramate maintenance dose was 86.0 mg/day. The mean duration of therapy was 91.7 days for the topiramate group and 90.6 days for the placebo group. Topiramate treatment resulted in a statistically significant mean reduction of migraine/migrainous headache days (topiramate -6.4 vs placebo -4.7, P= .010) and migraine headache days relative to baseline (topiramate -5.6 vs placebo -4.1, P= .032). Treatment-emergent adverse events occurred in 132 (82.5%) and 113 (70.2%) of topiramate-treated and placebo-treated subjects, respectively, and were generally of mild or moderate severity. Most commonly reported adverse events in the topiramate group were paresthesia (n = 46, 28.8%), upper respiratory tract infection (n = 22, 13.8%), and fatigue (n = 19, 11.9%). The most common adverse events in the placebo group were upper respiratory tract infection (n = 20, 12.4%), fatigue (n = 16, 9.9%), and nausea (n = 13, 8.1%). Discontinuations due to adverse events occurred in 18 (10.9%) topiramate subjects and 10 (6.1%) placebo subjects. There were no serious adverse events or deaths. CONCLUSIONS: Topiramate treatment at daily doses of approximately 100 mg resulted in statistically significant improvements compared with placebo in mean monthly migraine/migrainous and migraine headache days. Topiramate is safe and generally well tolerated in this group of subjects with chronic migraine, a burdensome condition with important unmet treatment needs. Safety and tolerability of topiramate were consistent with experience in previous clinical trials involving the drug.     

Topiramate Treatment of Chronic Migraine: A Randomized, Placebo-Controlled Trial of Quality of Life and Other Efficacy Measures

Objective.— To define yet more clearly the utility of topiramate in the treatment of chronic migraine, we evaluated prespecified secondary endpoints from a recent randomized, double‐blind, placebo‐controlled, multicenter clinical trial. Background.— We previously reported that topiramate 100 mg per day produced a statistically significant reduction in mean monthly migraine/migrainous and migraine headache days compared with placebo treatment and that it was safe and generally well tolerated. Methods.— Variables analyzed included between‐treatment group differences in percent responders, change in the mean monthly rate of total headache days and headache‐free days, change in average and worst daily headache severity, change in the mean monthly use of acute headache medications, and absolute change and percent change in a headache index. Additional analyses included evaluation of changes in: the associated symptoms of photophobia, phonophobia, and nausea; Migraine‐Specific Quality of Life Questionnaire scores; Migraine Disability Assessment Scale scores; and Physician's and Subjects Global Impression of Change. Results.— The intent‐to‐treat population consisted of 306 patients (topiramate, n = 153; placebo, n = 153). Categorical responder rates of reductions in mean monthly migraine/migrainous days for topiramate‐ vs placebo‐treated subjects were as follows: for ≥25% reduction: 68.6% vs 51.6% (P = .005); ≥50%: 37.3% vs 28.8% (P = .093); and ≥75%: 15.0% vs 9.2% (P = .061). The decrease in mean monthly total headache days and headache‐free days for topiramate vs placebo treatment was 5.8 vs 4.7 days (P = .067). Compared with placebo, topiramate treatment resulted in statistically significant mean improvements in the Role Restrictive (P = .028) and Emotional Function (P = .036) domains of the Migraine‐Specific Quality of Life Questionnaire, in the worst daily severity of migraine (P = .016), severity of photophobia (P = .032), frequency of vomiting (P = .018), photophobia (P = .038), phonophobia (P = .010), unilateral pain (P = .015), pulsatile pain (P = .023), and pain worsened because of physical activity (P = .047). In addition, there were trends observed (favoring topiramate) in average daily severity of migraine (P = .077), acute headache medication use (P = .127), severity of nausea (P = .098), frequency of nausea (P = .166), the Role Preventive domain of the Migraine‐Specific Quality of Life Questionnaire (P = .061), and severity of phonophobia (P = .062). Conclusions.— In addition to significantly reducing mean monthly migraine/migrainous and migraine headache days, treatment of chronic migraine with topiramate was effective with regard to several traditionally important and clinically relevant secondary outcomes in migraine prevention trials. Treatment with topiramate was well tolerated and not associated with serious adverse events.     

Pregabalin for relief of neuropathic pain associated with diabetic neuropathy: A randomized,double‐blind study

Seven published, randomized, placebo‐controlled clinical trials with pregabalin have shown robust efficacy for relief of neuropathic pain from DPN and PHN. An investigation of the efficacy and safety of twice daily pregabalin enrolled 395 adults with painful DPN for ≥1 year in a 12‐week, double‐blind, placebo‐controlled trial. Patients were randomized to placebo, 150, 300, or 600mg/day pregabalin (n=96, 99, 99, and 101). Primary efficacy measure was change from baseline in endpoint mean pain score from patients’ daily pain diaries. Secondary efficacy measures included pain‐related sleep‐interference scores, Patient and Clinical Global Impressions of Change (PGIC, CGIC), and the EuroQOL Health Utilities Index (EQ‐5D). Statistically significant reduction in pain was observed in patients receiving pregabalin 600mg/day, and 46% of patients treated with 600mg/day pregabalin reported ≥50% improvement in mean pain scores from baseline (vs 30% of placebo patients, p=0.036). Number needed to treat to achieve such response was 6.3. Pregabalin 600mg/day was significantly superior to placebo in improving pain‐related sleep‐interference scores (p=0.003), PGIC (p=0.021), and CGIC (p=0.009). (Neither pregabalin 150 nor 300mg/day separated from placebo on these measures, largely because of an atypically large placebo response in one country representing 42% of patients.) All pregabalin dosages were superior to placebo in improving EQ‐5D utility scores (all p≥0.0263 vs placebo). Pregabalin was well tolerated at all dosages; adverse events were generally mild to moderate. Number needed to harm (discontinuation because of adverse events) was 10.3 for pregabalin 600mg/day.     

Topiramate prophylaxis and response to triptan treatment for acute migraine

OBJECTIVE: To evaluate the effect of topiramate migraine prophylaxis on subject responsiveness to triptans used for acute symptomatic migraine treatment. BACKGROUND: Clinical experience suggests that prophylactic migraine treatment may enhance the efficacy of symptomatic medications used to treat acute migraine attacks. METHODS: This open-label, single-arm multicenter study consisted of a 6-week baseline period followed by a 16-week topiramate treatment period. Subjects meeting International Headache Society (IHS) criteria for migraine with and without aura signed consent and entered the baseline period. Those with 3 to 12 migraine periods per month during baseline received topiramate prophylactic treatment. Only patients who completed at least 12 weeks of topiramate treatment were included in the data analysis. RESULTS: Of 55 patients screened, 40 subjects entered the topiramate treatment period and 21 subjects received at least 12 weeks of treatment. Mean final dose of topiramate was 124 mg per day (range 50 to 200 mg per day). During the baseline period, the mean percentage of attacks rendered pain-free at 2 hours for the 21 subjects was 46.9% (SD = 31.9), while during the topiramate treatment period it was 44.6% (SD = 32.2) (P= .8). On topiramate, after the first 8 weeks of dosage titration, patients experienced a mean of 3.68 migraine attacks/month, compared to 4.31 during the baseline period (P < .03). Thirteen subjects discontinued because of adverse events. The most commonly reported adverse events were paresthesia, fatigue, anxiety, and dizziness. CONCLUSION: Although topiramate prophylaxis did reduce migraine attack frequency, in this pilot study topiramate prophylactic migraine treatment did not increase the proportion of patients pain-free 2 hours after symptomatic triptan therapy.     

Buprenorphine transdermal delivery system in adults with persistent noncancer-related pain syndromes who require opioid therapy: a multicenter, 5-week run-in and randomized, double-blind maintenance-of-analgesia study

OBJECTIVE: This study compared the efficacy and safety profile of buprenorphine transdermal delivery system (BTDS) and placebo in subjects with persistent noncancer-related pain who required opioid analgesics. METHODS: This was a multicenter, double-blind, parallel-group study in adult subjects (age >/=18 years) with at least a 2-month history of noncancer-related pain for which they received oral opioid combination agents. The study employed a maintenance-of-analgesia, or randomized-withdrawal, design. During a 7- to 21-day open-label run-in phase, all subjects received BTDS, titrated as needed. Subjects who achieved stable pain control and were able to tolerate BTDS in the run-in phase were randomly assigned to continue BTDS at the dose achieved during the run-in phase or to receive placebo for up to 14 days. Acetaminophen 500-mg tablets were provided as escape (rescue) medication. Subjects completed the study on day 14 or when they met predefined criteria for ineffective treatment: requiring >1 g of acetaminophen as escape medication on any day of the double-blind evaluation phase, requiring a change in study drug dose, having difficulty keeping the patch affixed, or discontinuing because of ineffective treatment without meeting any of the first 3 criteria. The primary efficacy variable was the proportion of subjects with ineffective treatment. Secondary efficacy variables were the time to ineffective treatment; the proportion of subjects who reached ineffective treatment or discontinued for any reason other than ineffective treatment; and the amount of escape medication used. Assessment of the safety profile was based on adverse events and changes in vital signs and physical and laboratory findings. RESULTS: Five hundred eighty-eight subjects entered the open-label run-in phase, and 267 (129 BTDS, 138 placebo) were subsequently randomized to doubleblind treatment. Demographic characteristics were similar between the double-blind BTDS and placebo groups (61.2% and 63.8% female, respectively; 99.2% and 98.6% white; mean [SD] age, 56.2 [13.3] and 59.2 [11.5] years). In the primary efficacy analysis, the proportion of subjects with ineffective treatment was lower with BTDS than with placebo (51.2% vs 65.0%; 95% CI, 1.09-2.95); the odds of ineffective treatment were 1.79 times greater for placebo relative to BTDS (P = 0.022). In the secondary efficacy analyses, the median time from the first dose of double-blind study drug to ineffective treatment was significantly longer with BTDS than with placebo (median, 10 vs 3 days; P = 0.011). The proportion of subjects who reached ineffective treatment or discontinued for reasons other than ineffective treatment was lower in the BTDS group compared with the placebo group (55.0% vs 67.9%); the odds of ineffective treatment or discontinuation for a reason other than ineffective treatment was 1.76 times greater with placebo compared with BTDS (P = 0.028). The mean amount of escape medication used was significantly lower in the BTDS group than in the placebo group (1.7 vs 2.2 acetaminophen tablets per day; P = 0.015). The most common adverse events in the open-label run-in or double-blind phase occurring at a higher incidence with BTDS than with placebo were pruritus at the patch application site (9.3% vs 5.1%, respectively), headache (3.9% vs 2.2%), and somnolence (2.3% vs 0.7%). CONCLUSION: In this population of adult subjects with persistent noncancer-related pain who required opioid therapy, BTDS use was associated with analgesic efficacy and was generally well tolerated. Results of this study were presented in part at the annual meeting of the American Pain Society, March 30-April 2, 2005, Boston, Massachusetts.     

Topiramate in migraine prevention: a double-blind, placebo-controlled study

OBJECTIVE: To evaluate the efficacy of topiramate in the preventative treatment of episodic migraine. BACKGROUND: Topiramate is a broad-spectrum antiepileptic drug effective for treatment of multiple seizure types in adults and children. Antiepileptic agents have demonstrated efficacy in migraine prevention, and open-label experience from our clinic has suggested that topiramate might be effective for this use. We consequently conducted a single-center, double-blind, placebo-controlled trial to evaluate the efficacy and safety of topiramate for the preventative treatment of migraine. METHODS: Forty patients, aged 19 to 62 years (mean, 38.2 years), were randomly assigned in a 1:1 ratio to receive topiramate (n = 19; all women) or placebo (n = 21; 20 women, 1 man). Following a prospective baseline phase of 4 weeks, the study drug dose was titrated weekly in 25-mg increments over 8 weeks to 200 mg per day or to the maximum tolerated dose. The titration phase was followed by an 8-week maintenance phase. RESULTS: During the entire double-blind phase, topiramate-treated patients experienced a significantly lower 28-day migraine frequency (3.31 +/- 1.7 versus 3.83 +/- 2.1; P =.002) compared to placebo, irrespective of use of concomitant migraine prevention medications. The mean 28-day migraine frequency was reduced by 36% in patients receiving topiramate as compared with 14% in patients receiving placebo (P =.004). Twenty-six percent of the patients on topiramate and 9.5% of the patients on placebo achieved a 50% reduction in migraine frequency (P >.05). The mean dose of topiramate was 125 mg per day (range, 25 to 200 mg per day). Topiramate was well tolerated; 2 of 19 topiramate-treated patients discontinued treatment due to adverse events. Adverse effects that occurred more frequently in topiramate-treated patients included paresthesia, weight loss, altered taste, anorexia, and memory impairment. CONCLUSIONS: Preventative therapy with topiramate significantly reduced migraine frequency. Larger multicenter clinical studies may further delineate the role of topiramate in migraine prevention.     

Sativex successfully treats neuropathic pain characterised by allodynia: a randomised, double-blind, placebo-controlled clinical trial

Cannabinoids are known to have analgesic properties. We evaluated the effect of oro-mucosal sativex, (THC: CBD), an endocannabinoid system modulator, on pain and allodynia, in 125 patients with neuropathic pain of peripheral origin in a five-week, randomised, double-blind, placebo-controlled, parallel design trial. Patients remained on their existing stable analgesia. A self-titrating regimen was used to optimise drug administration. Sixty-three patients were randomised to receive sativex and 62 placebo. The mean reduction in pain intensity scores (primary outcome measure) was greater in patients receiving sativex than placebo (mean adjusted scores -1.48 points vs. -0.52 points on a 0-10 Numerical Rating Scale (p=0.004; 95% CI: -1.59, -0.32). Improvements in Neuropathic Pain Scale composite score (p=0.007), sleep NRS (p=0.001), dynamic allodynia (p=0.042), punctate allodynia (p=0.021), Pain Disability Index (p=0.003) and Patient's Global Impression of Change (p<0.001) were similarly greater on sativex vs. placebo. Sedative and gastrointestinal side effects were reported more commonly by patients on active medication. Of all participants, 18% on sativex and 3% on placebo withdrew during the study. An open-label extension study showed that the initial pain relief was maintained without dose escalation or toxicity for 52 weeks.     

Metabolic effects of two years of exenatide treatment on diabetes, obesity, and hepatic biomarkers in patients with type 2 diabetes: an interim analysis of data from the open-label, uncontrolled extension of three double-blind, placebo-controlled trials

BACKGROUND: Exenatide, an incretin mimetic for adjunctive treatment of type 2 diabetes mellitus (T2DM), reduced glycosylated hemoglobin (HbA(1c)) and weight in 30-week placebo-controlled trials. Some patients were followed up in open-label extensions to provide 'real-world' exenatide clinical experience. OBJECTIVE: The purpose of this study was to examine the metabolic effects of 2 years of exenatide treatment in patients with T2DM. METHODS: For this interim analysis, data were pooled from patients who completed 1 of three 30-week, multicenter, double-blind, placebo-controlled trials and their open-label extensions. In the initial trials, subjects were randomized to BID 5-microg exenatide, 10-microg exenatide, or placebo for 30 weeks. All subjects who enrolled in the extension phase then received 5-pg exenatide BID for 4 weeks, followed by open-label treatment with 10-pg exenatide BID. Subjects continued their existing metformin and/or sulfonylurea regimens. Analyses were conducted on data from all subjects who had the opportunity to achieve 2 years of exenatide exposure, irrespective of their treatment arm in the 30-week placebo-controlled trials. RESULTS: A total of 974 patients entered the open-label, extension phase of the trial. Two hundred eighty-three subjects (mean [SD] age, 57 [10] years; mean [SD] weight, 100[19] kg; sex, 63% male; mean [SD] body mass index, 34 [6] kg/m(2); mean [SD] HbA(1c), 8.3% [1.0%]) completed 2 years of exenatide treatment. Reductions in mean (SE) HbA(1c) from baseline to week 30 (-0.9% [0.1%]) were sustained through 2 years (-1.1% [0.1%]; P < 0.05 vs baseline), with 50% of the population achieving HbA(1c) < or = 7%. At week 30, exenatide was associated with a significant reduction in mean (SD) body weight from baseline (-2.1 [0.2] kg), with progressive reductions after 2 years (-4.7 [0.3] kg; P < 0.001 vs baseline). Patients with normal baseline alanine aminotransferase (ALT) (132/283 [47%]; normal: female < or =19 IU/L; male < or =30 IU/L) had no significant ALT change. However, patients with elevated ALT at baseline (151/283 [53%]) had a mean (SEM) reduction of ALT (-11 [1] IU/L from baseline 38 [1] IU/1; P < 0.05) and 39% achieved normal ALT by week 104. Patients with elevated ALT at baseline lost significantly more weight than patients with normal ALT at baseline (P = 0.04). However, weight change was minimally correlated with baseline ALT (r = -0.09) or ALT change (r = 0.31). Also, homeostasis model assessment of the beta-cell function (HOMA-B), blood pressure, and aspartate aminotransferase (AST) all improved. The most frequently reported adverse event was mild-to-moderate nausea. CONCLUSIONS: In these patients with T2DM, adjunctive exenatide treatment for 2 years was generally well tolerated and resulted in a sustained reduction of HbA(1c), progressive reduction in weight, and improvements in HOMA-B, blood pressure, and the hepatic injury biomarkers, AST and ALT.     

Dextromethorphan and quinidine in adult patients with uncontrolled painful diabetic peripheral neuropathy: a 29-day, multicenter, open-label, dose-escalation study

BACKGROUND: Pain associated with diabetic peripheral neuropathy (DPN) has a substantial negative impact on patients' quality of life. OBJECTIVES: The primary objective of this study was to evaluate the tolerability of capsules containing dextromethorphan (DM) and quinidine (Q) in patients with painful DPN. A secondary objective was to perform a preliminary assessment of the efficacy of DM/Q in this patient population. METHODS: This was a multicenter, open-label, dose-escalation study. Eligible patients were aged between 18 and 80 years, had a confirmed diagnosis of diabetes with acceptable glycemic control, had been receiving established diabetic therapy for at least 3 months, and had a clinical diagnosis of distal symmetric sensory neuropathy with daily DPN-associated pain for the previous 3 months. On study entry, patient-rated diabetic pain had to be moderate or greater. Patients who met the inclusion criteria underwent a 2-week washout period during which all analgesics were discontinued, followed by 29 days of treatment with capsules containing DM 30 mg and Q 30 mg (DM30/Q30), beginning with 1 capsule/d and escalating at approximately 1-week intervals, as tolerated, to a maximum dose of 4 capsules/d (DM120/Q120). Tolerability was assessed based on adverse events and changes in clinical and laboratory parameters and nerve conduction velocity. Preliminary efficacy assessments included changes from baseline in scores on the pain intensity rating scale (PIRS), pain relief rating scale (PRRS), peripheral neuropathy quality-of-life instrument, and patients' diary assessments of sleep, present pain intensity, pain, and activity. RESULTS: The study included 36 men and women (mean age, 58 years; mean body mass index, 32.8 kg/m(2)). Of the 33 subjects who completed the study, 23 (69.7%) did so at the highest permitted dose (DM120/Q120). The most commonly reported adverse events (occurring in > or =5% of subjects) were nausea (27.8%), dizziness (25.0%), and headache (25.0%). Three patients experienced 5 serious adverse events, only 1 of which was considered possibly related to study drug. The most commonly occurring laboratory abnormalities (involving glycosylated hemoglobin, serum glucose, triglycerides, and cholesterol) were considered typical of a population with diabetes. Improvements from baseline in scores on the PIRS, PRRS, and other exploratory efficacy measures were noted (P < 0.001). CONCLUSIONS: The results of this open-label study indicated that the combination of DMIQ (dose range, DM30/Q30-DM120/Q120) was well tolerated in patients with pain associated with DPN. Based on the preliminary efficacy results, a randomized, controlled, double-blind trial is warranted to assess the tolerability and efficacy of this combination in patients with DPN.     

Treatment of symptomatic diabetic peripheral neuropathy with the protein kinase C beta-inhibitor ruboxistaurin mesylate during a 1-year, randomized, placebo-controlled, double-blind clinical trial

OBJECTIVE: The aim of this study was to assess the effects of ruboxistaurin (RBX) mesylate on nerve function and sensory symptoms in patients with diabetes mellitus (DM) and diabetic peripheral neuropathy (DPN). METHODS: Patients were enrolled in a multinational, randomized, Phase II, double-blind, placebo-controlled parallel-group trial comparing 32 mg/d or 64 mg/d RBX with placebo for 1 year. DPN was identified by abnormal measurable vibration detection threshold (VDT) and verified by abnormal neurologic examination and nerve electrophysiology measures. Baseline patient characteristics (eg, sex, type of DM, age, body mass index, glycosylated hemoglobin, and duration of DM and DPN) were measured. The primary end point was the change in VDT. Secondary end point measures included effects of RBX versus placebo on Neuropathy Total Symptom Score-6 (NTSS-6), neurologic examination, electrophysiologic nerve conduction studies, Neuropathy Impairment Score, Clinical Global Impressions, and safety. A post-hoc analysis was performed on patients with less severe DPN (sural sensory nerve action potential > or =0.5 microV and NTSS-6 total score >6). RESULTS: Two hundred five patients were assessed: 66 were assigned to the RBX 32 mg/d group, 71 to the RBX 64 mg/d group, and 68 to the placebo group. The demographic and baseline characteristics of the treatment groups were well matched between the RBX 32 mg/d, RBX 64 mg/d, and placebo groups: mean (SD) age, 45.6 (8.41) years; 122 (60%) men, 83 (40%) women; 110 (54%) with type 1 DM, 95 (46%) with type 2 DM; mean (SD) duration of DPN, 3.4 (4.21) years. The RBX 32 mg/d group had slightly more patients with type 1 DM (P = 0.05). Eighty-three patients had clinically significant symptoms at baseline (defined as NTSS-6 total score >6: RBX 32 mg/d, n = 22; RBX 64 mg/d, n = 26; placebo, n = 35); 122 patients had NTSS-6 total scores < or =6. No treatment differences were observed for change in VDT. Among the 83 patients with significant symptoms at baseline, there was a reduction from baseline at 12 months in the NTSS-6 total score in the RBX 32 mg/d (P = NS) and RBX 64 mg/d (P = 0.015) groups compared with placebo. In a subgroup of patients with clinically significant symptoms and less severe DPN (n = 50), there was a significantly greater reduction in the NTSS-6 total score with RBX 64 mg/d (P = 0.006 vs placebo). Furthermore, in these patients, there was a statistically significant improvement in VDT for both RBX 32 mg/d (P = 0.012) and RBX 64 mg/d (P = 0.026) compared with placebo. CONCLUSIONS: RBX appeared to be well tolerated in the patients with DPN who participated in this study. Overall, changes in VDT and NTSS-6 total scores did not differ among treatment groups at end point. However, RBX treatment appeared to be of benefit for the subgroup of patients with less severe symptomatic DPN by relieving sensory symptoms and improving nerve fiber function, as indicated by reductions in VDT and NTSS-6 total score.     

Gene therapy for diabetic peripheral neuropathy: A randomized,placebo‐controlled phase III study of VM202, a plasmid DNA encoding human hepatocyte growth factor

AbstractVM202 is a plasmid DNA encoding two isoforms of hepatocyte growth factor (HGF). A previous phase II study in subjects with painful diabetic peripheral neuropathy (DPN) showed significant reductions in pain. A phase III study was conducted to evaluate the safety and efficacy of VM202 in DPN. The trial was conducted in two parts, one for 9 months (DPN 3‐1) with 500 subjects (VM202: 336 subjects; and placebo: 164) and a preplanned subset of 101 subjects (VM202: 65 subjects; and placebo: 36) with a noninterventional extension to 12 months (DPN 3‐1b). VM202 or placebo was administered to calf muscles on days 0 and 14, and on days 90 and 104. The primary end point in DPN 3‐1 was change from baseline in the mean 24‐h Numerical Rating Scale (NRS) pain score. In DPN 3‐1b, the primary end point was safety, whereas the secondary efficacy end point was change in the mean pain score. VM202 was well‐tolerated in both studies without significant adverse events. VM202 failed to meet its efficacy end points in DPN 3‐1. In DPN 3‐1b, however, VM202 showed significant and clinically meaningful pain reduction versus placebo. Pain reduction in DPN 3‐1b was even greater in subjects not receiving gabapentin or pregabalin, confirming an observation noted in the phase II study. In DPN 3‐1b, symptomatic relief was maintained for 8 months after the last injection suggesting that VM202 treatment might change disease progression. Despite the perplexing discrepancy between the two studies, the safety and long‐lasting pain‐relieving effects of VM202 observed in DPN 3‐1b warrant another rigorous phase III study. Study Highlights

• WHAT IS THE CURRENT KNOWLEDGE ON THE TOPIC?

Current therapies for painful diabetic peripheral neuropathy (DPN) are palliative and do not target the underlying mechanisms. Moreover, symptomatic relief is often limited with existing neuropathic pain drugs. Thus, there is a great medical need for safer and effective treatments for DPN.

• WHAT QUESTION DID THIS STUDY ADDRESS?

Can nonviral gene delivery of hepatocyte growth factor reduce pain in patients with DPN and potentially modify progression of the disorder?

• WHAT DOES THIS STUDY ADD TO OUR KNOWLEDGE?

Nonviral gene therapy can be used safely and practically to treat DPN.

• HOW MIGHT THIS CHANGE CLINICAL PHARMACOLOGY OR TRANSLATIONAL SCIENCE?

As the first gene medicine to enter advanced clinical trials for the treatment of DPN, this study provides the proof of concept of an entirely new potential approach to the disorder.     

Tramadol/acetaminophen combination tablets for the treatment of chronic lower back pain: a multicenter,randomized, double-blind,placebo-controlled outpatient study

BACKGROUND: Tramadol and acetaminophen (APAP) have both shown efficacy in the treatment of lower back pain. The combination of these 2 agents has demonstrated synergistic analgesic action in animal models at specific ratios. OBJECTIVE: This study assessed the long-term (3-month) efficacy and safety of tramadol 37.5 mg/APAP 325 mg combination tablets in the treatment of chronic lower back pain. METHODS: Patients with at least moderate lower back pain (pain visual analog [PVA] score >/=40 mm on a 100-mm scale) were randomized to receive up to 8 tablets of tramadol/APAP per day or placebo for 91 days. Medication was titrated from 1 to 4 tablets/d by day 10. The primary efficacy measure was PVA score at the final visit. Secondary measures included scores on the Pain Relief Rating Scale (PRRS), Short-Form McGill Pain Questionnaire (SF-MPQ), Roland Disability Questionnaire (RDQ), and 36-Item Short-Form Health Survey (SF-36); the incidence of discontinuation due to insufficient pain relief (Kaplan-Meier analysis); and overall assessments of medication by the patients and investigators. RESULTS: Three hundred eighteen patients (161 tramadol/APAP, 157 placebo) were included in the intent-to-treat population, defined as all patients who took >/=1 dose of study medication and had >/=1 postrandomization efficacy measurement. The mean age of the study population was 53.9 years, 63.2% were female, 90.3% were white, and the mean baseline PVA score was 70.0 mm. There were no significant differences between groups at baseline. Tramadol/APAP significantly improved final PVA scores (P = 0.015) and final PRRS scores (P < 0.001) compared with placebo. Tramadol/APAP also significantly improved RDQ scores (P 相似文献   

Assessing the ability of topiramate to improve the daily activities of patients with migraine

OBJECTIVE: To assess the impact of topiramate on the daily activities of patients with migraine. PATIENTS AND METHODS: We performed a randomized, double-blind, placebo-controlled multicenter trial Initiated on March 1, 2001, and completed on April 4, 2002. Patient-reported data from the Migraine Specific Questionnaire (MSQ) and the Medical Outcomes Study 36-item Short-Form Health Survey (SF-36) were collected at baseline and at weeks 8, 16, and 26 from an intent-to-treat population receiving either topiramate, 50, 100, or 200 mg/d, or placebo. Two activity-related MSQ domains (role restrictive [MSQ-RR] and role prevention [MSQ-RP]) and 2 activity-related SF-36 domains (role physical [SF36-RP] and vitality [SF36-VT]) were the prospectively designated secondary outcome measures. The changes in MSQ and SF-36 scores for each treatment group were calculated by measuring the area under the curve from week 8 (the beginning of the maintenance period) through week 26 of the double-blind phase, relative to the prospective baseline. A mixed-effect piecewise linear regression model was used to estimate average domain score over time. RESULTS: Patients receiving topiramate, 100 or 200 mg/d, had significantly reduced mean monthly (28-day) migraine frequency (P = .008 and P < .001, respectively) compared with placebo, but not patients receiving topiramate, 50 mg/d (P = .48). Topiramate significantly improved mean MSQ-RR domain scores (50 mg/d [P = .02], 100 mg/d [P< .001], and 200 mg/d [P < .001]) and mean MSQ-RP domain scores (50 mg/d [P = .007], 100 mg/d [P = .001], and 200 mg/d [P= .002]) vs placebo. Topiramate, 100 and 200 mg/d, significantly improved mean SF36-RP domain scores vs placebo (P = .02). Topiramate (all doses) improved SF36-VT domain scores, although not significantly vs placebo. Changes in prospectively designated domain scores were significantly correlated with changes in mean monthly migraine frequency (P < or = .001 [MSQ domains], P < or = .002 [SF-36 domains]). CONCLUSION: Patient-reported migraine-specific outcomes measured by the MSQ-RR and MSQ-RP domains improved significantly for those receiving topiramate (all doses) vs placebo. The SF36-RP domain scores improved significantly for patients receiving 100 or 200 mg/d of topiramate. Improvements in all 4 prospectively selected MSQ and SF-36 domains were significantly correlated with decreases in mean monthly migraine frequency.     

Fentanyl buccal tablet for the relief of breakthrough pain in opioid-tolerant adult patients with chronic neuropathic pain: a multicenter, randomized, double-blind, placebo-controlled study

BACKGROUND: Patients with chronic noncancer pain, including neuropathic pain, may have transitory exacerbations of pain (median duration, 60 minutes), termed breakthrough pain (BTP), that may reach peak intensity within minutes. Typical short-acting oral opioids may not provide sufficiently rapid relief (30- to 60-minute onset of analgesia). The fentanyl buccal tablet (FBT) provides a rapid onset of analgesia (10-15 minutes) by enhancing fentanyl absorption across the buccal mucosa. OBJECTIVE: This study evaluated the efficacy and tolerability of FBT in opioid-tolerant patients with BTP associated with chronic noncancer neuropathic pain. METHODS: This was a multicenter, randomized, double-blind, placebo-controlled study in men and women aged 18 to 80 years who were opioid tolerant; had a >/= 3-month history of chronic persistent neuropathic pain associated with diabetic peripheral neuropathy, postherpetic neuralgia, traumatic injury, or complex regional pain syndrome; and reported having episodes of BTP. After an open-label titration period to identify an effective FBT dose (the dose at which the patient reported receiving adequate pain relief within 30 minutes after administration of a single tablet of that dose during at least 2 of 3 BTP episodes), patients were randomly assigned to treat 9 consecutive episodes of BTP over the next 21 days with 1 of 3 double-blind dose sequences of FBT and placebo tablets. Pain intensity (PI) (rated on an 11-point pain scale, from 0 = no pain to 10 = worst pain) and other outcomes were assessed before dosing and for 2 hours after dosing. The primary efficacy measure was the sum of PI differences (PIDs) for the first 60 minutes (SPID(60)). Secondary efficacy measures included the proportion of BTP episodes with >/= 33% and >/= 50% improvement in PI from baseline; PID at other time points (5, 10, 15, 30, 45, 60, 90, and 120 minutes after dosing); pain relief (PR) at the same time points (rated on a 5-point Likert scale from 0 = none to 4 = complete); proportion of BTP episodes with meaningful PR; time to meaningful PR; and proportion of BTP episodes in which supplemental medication was required after administration of study drug. Adverse events (AEs) spontaneously reported by the patient or elicited by the investigator were recorded throughout the study. RESULTS: Of 102 patients in the open-label titration period, 80 identified an effective dose of FBT and 79 entered the double-blind phase. Of these 79 patients, 77 (97%) completed the study and 75 (95%) were evaluable for efficacy. Of the 79 patients who entered the double-blind phase, 63% were women and 92% were white; their mean (SD) age was 48.3 (10.42) years, and their mean weight was 96.8 (33.42) kg. Baseline demographic and pain characteristics were similar between the overall population and the double-blind population. SPID(60) was significantly greater for BTP episodes treated with FBT compared with those in which placebo was administered (mean [SE], 9.63 [0.75] vs 5.73 [0.72], respectively; P < 0.001). Significant differences between FBT and placebo were seen beginning at 10 minutes for PID (mean, 0.740 [0.149] vs 0.427 [0.081]; P < 0.047) and PR (mean, 0.561 [0.087] vs 0.324 [0.056]; P < 0.001). A >/= 33% improvement in PI from baseline was seen in a greater proportion of BTP episodes treated with FBT compared with placebo from 10 minutes (9% vs 3%; P = 0.008) through 2 hours (66% vs 37%; P < 0.001). Patients were almost 4 times less likely to require supplemental opioids when BTP episodes were treated with FBT compared with placebo (odds ratio = 0.28; 95% Cl, 0.18-0.42). AEs were reported by 64 (63%) of 102 patients. The most commonly reported AEs were those typical of opioids (nausea [13%], dizziness [13%], somnolence [10%], and vomiting [5%]) and occurred more often during the dose-titration phase (55/102 [54%]) than during the double-blind phase (22/79 [28%]). CONCLUSION: In these opioid-tolerant patients with chronic neuropathic pain who identified an effective FBT dose, FBT had a rapid onset of action and was effective and well tolerated in the treatment of BTP.     

Topiramate for migraine prevention in adolescents: a pooled analysis of efficacy and safety

OBJECTIVE: To characterize the efficacy and safety of topiramate for migraine prevention in adolescents from 3 randomized, 26-week, double-blind, placebo-controlled trials. BACKGROUND: Limited information is available regarding the efficacy and safety of prophylactic medications for treatment of adolescent migraine, a significant health problem. In studies that included adults and children, topiramate 100 and 200 mg/day were effective and generally well-tolerated in the prevention of migraine headache. METHODS: We performed a post hoc subset analysis of the efficacy and safety data from the 51 patients, ages 12-17 years, enrolled in 3 pivotal trials of topiramate for migraine prophylaxis. RESULTS: Daily treatment with topiramate 50, 100, and 200 mg for 26 weeks reduced monthly migraine frequency from baseline 46% (P= .07), 63% (P= .02), and 65% (P= .04), respectively, compared with placebo (16%). Similarly, topiramate reduced both the monthly mean number of migraine days (1, 4, and 5 days for topiramate 50, 100, and 200 mg/day, respectively, vs 1 day for placebo) and percentage of days during which acute migraine medications were administered (59%, 54%, and 67% for topiramate 50, 100, and 200 mg/day, respectively, vs 42% for placebo), although the treatment differences did not reach nominal statistical significance. Topiramate 200 mg/day did not appear to offer greater efficacy than 100 mg/day. Treatment was generally well-tolerated, although adverse events were most frequent in the 200 mg/day dose group. CONCLUSIONS: This post hoc subset analysis suggests that topiramate 100 and 200 mg/day, and possibly 50 mg/day, administered prophylactically for 26 weeks may reduce migraine in adolescents.     

Topiramate in patients with episodic migraine: reducing the risk for chronic forms of headache

OBJECTIVE: The aim was to evaluate whether preventive treatment with topiramate in patients with episodic migraine reduces the risk of developing chronic forms of headache. BACKGROUND: Chronic forms of headache, including chronic migraine or medication overuse headache (MOH), are characterized by 15 or more headache days per month. Acute medication overuse has been shown to be a risk factor for developing chronic headache, but it is not known whether preventive treatment can reduce the risk of developing chronic forms of headache or the development of MOH. METHODS: Pooled data from 3 trials in patients with episodic migraine randomized either to treatment with 100 mg topiramate per day (n = 384) or with placebo (n = 372) were analyzed with regard to the number of headache days during a prospective 4-week baseline period and the individual final 4 weeks of each patient's treatment during the planned 26-week double-blind treatment period. RESULTS: The number of headache days per month in the topiramate versus the placebo-treated groups was 7.3 +/- 3.0 versus 7.3 +/- 3.1 during baseline and 4.1 +/- 4.2 versus 5.6 +/- 4.9 during the final 4 weeks, respectively (P < .001). At the end of the study, 8 versus 16 patients fulfilled International Headache Society criteria of chronic headache (odds ratio: 2.11, P= .082). Moreover, a significantly lower number of patients receiving topiramate treatment reported an increase in headache days per month by the end of the study when compared to placebo (66 vs 88 patients, respectively; odds ratio: 1.49, P < .05). Finally, the number of days with usage of acute medication was significantly lower in the topiramate arm compared with placebo (3.3 +/- 3.7 vs 4.3 +/- 3.6, respectively; P < .001). CONCLUSION: Preventive treatment with topiramate in patients with episodic migraine may reduce the risk of developing chronic forms of headache.     

Efficacy and safety of a once-daily morphine formulation in chronic, moderate-to-severe osteoarthritis pain: results from a randomized, placebo-controlled, double-blind trial and an open-label extension trial

A randomized, 4-week, double-blind trial followed by an open-label extension trial assessed the efficacy and safety of a once-daily, extended-release morphine formulation (Avinza (previously referred to as Morphelan)) in 295 patients with chronic, moderate-to-severe osteoarthritis pain who had failed to obtain adequate pain relief with NSAIDs and acetaminophen. Participants received one of four treatments: Avinza 30 mg once daily (QAM or QPM), MS Contin(R) 15 mg twice daily, or placebo twice daily. Patients (n =181) received Avinza QAM or QPM during the 26-week open-label extension trial and could increase their dose to optimize pain control. Avinza and MS Contin reduced pain and improved several sleep measures versus placebo. Analgesic efficacy was comparable between Avinza and MS Contin; however, Avinza QAM demonstrated greater improvements in overall quality of sleep. The most common adverse events were constipation and nausea. The majority of AEs occurred at a similar incidence among the active treatment groups.