Efficacy and Safety of Once-Daily Controlled-Release Pregabalin for the Treatment of Patients With Postherpetic Neuralgia: A Double-Blind, Enriched Enrollment Randomized Withdrawal, Placebo-Controlled Trial.

OBJECTIVES: To assess efficacy and safety of once-daily controlled-release (CR) formulation of pregabalin in patients with postherpetic neuralgia. METHODS: An enriched enrollment, randomized withdrawal trial, with 6-week single-blind pregabalin treatment phase and 13-week double-blind phase, where patients with ≥50% decrease in mean pain score at single-blind end point from baseline were randomized (1:1) to pregabalin CR (82.5 to 660 mg/d) or placebo. Primary efficacy outcome was time to loss of therapeutic response (LTR) (<30% decrease in weekly mean pain score from single-blind baseline or discontinuation due to adverse event or lack of efficacy). Secondary efficacy outcomes included change in weekly mean pain score (1-wk recall period) at double-blind end point. RESULTS: In total, 801 patients were randomized and treated in the single-blind phase, and 413 in the double-blind phase (208, pregabalin CR; 205, placebo). Pregabalin CR significantly increased time to LTR versus placebo (Kaplan-Meier analysis) with significantly fewer LTR events with pregabalin CR than with placebo (29 [13.9%] vs. 63 [30.7%]; P<0.0001). Median time to LTR was not estimable. Pregabalin CR significantly improved weekly mean pain score versus placebo: LS mean difference (95% CI) of -1.11 (-1.47, -0.75) and -1.00 (-1.34, -0.65) (P<0.0001) from single-blind baseline and double-blind baseline, respectively. Most commonly reported adverse events in the single-blind phase were dizziness, somnolence, and peripheral edema. Pregabalin CR was well tolerated. DISCUSSION: Time to LTR was significantly longer with pregabalin CR than with placebo. Safety profile of pregabalin CR was comparable to that reported for the immediate-release formulation in patients with postherpetic neuralgia.

Pregabalin in Patients With Painful Diabetic Peripheral Neuropathy Using an NSAID for Other Pain Conditions: A Double-Blind Crossover Study.

OBJECTIVES: To evaluate pregabalin's efficacy and safety versus placebo to reduce pain in patients with diabetic peripheral neuropathy (DPN) using a concomitant nonsteroidal anti-inflammatory drug. MATERIALS AND METHODS: In a randomized, double-masked, 14-week, 2-period, crossover study, patients with painful DPN using a nonsteroidal anti-inflammatory drug for non-DPN-related pain received 150 to 300 mg/d pregabalin or placebo (period 1); 14-day washout; then, the opposite therapy (period 2). Endpoints included weekly change in DPN pain score, sleep interference, adverse events, and patient-reported outcomes. RESULTS: Patients with similar baseline characteristics were randomized (period 1) to 1 of the 2 following possible sequences: pregabalin→placebo (n=154) or placebo→pregabalin (n=147). Results of the primary efficacy measure, mean weekly DPN pain at endpoint, showed no significant difference between pregabalin and placebo. However, 1 sensitivity analysis (mixed-model repeated measures) found greater pain score reductions with pregabalin than placebo at weeks 2 to 4 and overall (all P<0.05). One secondary endpoint analysis, mean treatment difference in DPN-related sleep interference, favored pregabalin over placebo (P=0.0009). Other sensitivity and secondary analyses were nonsignificant. Treatment-emergent adverse events were consistent with the known safety profile of pregabalin. DISCUSSION: Pregabalin (vs. placebo) showed overall improvements in sleep, pain reduction in 1 sensitivity analysis, and was well tolerated. Potential factors that may have confounded the ability to detect a treatment difference in DPN pain reduction (high placebo response, carryover effect, short washout period, or pregabalin dose) are discussed in the context of future studies.

Efficacy and Safety of Pregabalin in the Treatment of Patients With Painful Diabetic Peripheral Neuropathy and Pain on Walking.

OBJECTIVES: This randomized, double-blind, placebo-controlled, multicenter, 2-period crossover study (two 6-week treatment periods separated by a 2-week washout period) evaluated the efficacy and safety of pregabalin (150 to 300 mg/d) for treatment of pain and pain on walking in patients with painful diabetic peripheral neuropathy (DPN) who experienced pain while walking. METHODS: Co-primary efficacy endpoints were: (1) mean pain score (last 7 daily pain diary scores, 0 to 10 numeric rating scale at end of each treatment period) and (2) DPN pain on walking (0 to 10 numeric rating scale immediately after walking 50 feet [15.2 m] on flat surface). Secondary endpoints included other pain parameters, patient-reported sleep, health-related quality of life, and safety measures. RESULTS: Two hundred three patients were treated (pregabalin, n=198; placebo, n=186), with no statistically significant treatment difference for pregabalin versus placebo in the co-primary efficacy endpoints, mean DPN pain (P=0.0656) and mean DPN pain on walking (P=0.412). A carryover effect was observed. Analysis of co-primary endpoints for period 1 showed significant treatment difference for DPN pain (P=0.034) and DPN pain on walking (P=0.001). Treatment with pregabalin resulted in significant improvements versus placebo on prespecified patient global impression of change (end of period 1; P=0.002), and sleep interference rating scale (end of period 2; P=0.011). Adverse events were more frequent with pregabalin than with placebo and caused discontinuation in 13 (6.6%) pregabalin patients versus 5 (2.7%) placebo patients. DISCUSSION: Failure to meet the co-primary objectives may be related to carryover effect from period 1 to period 2, lower pregabalin dose (150 to 300 mg/d), and/or placebo response in painful DPN.

Once daily controlled-release pregabalin in the treatment of patients with fibromyalgia: a phase III, double-blind, randomized withdrawal, placebo-controlled study.

OBJECTIVE: Safety and efficacy of a once daily controlled-released (CR) formulation of pregabalin was evaluated in patients with fibromyalgia using a placebo-controlled, randomized withdrawal design. RESEARCH DESIGN AND METHODS: This multicenter study included 6 week single-blind pregabalin CR treatment followed by 13 week double-blind treatment with placebo or pregabalin CR. The starting dose of 165 mg/day was escalated during the first 3 weeks, up to 495 mg/day based on efficacy and tolerability. Patients with ≥50% reduction in average daily pain score at the end of the single-blind phase were randomized to continue pregabalin CR at the optimized dose (330-495 mg/day) or to placebo. The primary endpoint was time to loss of therapeutic response (LTR), defined as <30% pain reduction relative to single-blind baseline or discontinuation owing to lack of efficacy or adverse event (AE). Secondary endpoints included measures of pain severity, global assessment, functional status, tiredness/fatigue, and sleep. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov NCT01271933. RESULTS: A total of 441 patients entered the single-blind phase, and 63 were randomized to pregabalin CR and 58 to placebo. The median time to LTR (Kaplan-Meier analysis) was significantly longer in the pregabalin CR group than placebo (58 vs. 22 days, p = 0.02). By trial end, 34/63 (54.0%) pregabalin CR and 41/58 (70.7%) placebo patients experienced LTR. Significantly more patients reported 'benefit from treatment' (Benefit, Satisfaction, and Willingness to Continue Scale) in the pregabalin CR group; no other secondary endpoints were statistically significant. Most AEs were mild to moderate in severity (most frequent: dizziness, somnolence). The percentage of pregabalin CR patients discontinuing because of AEs was 12.2% and 4.8% in the single-blind and double-blind phases, respectively (placebo, 0%). CONCLUSIONS: Time to LTR was significantly longer with pregabalin CR versus placebo in fibromyalgia patients who initially showed improvement with pregabalin CR, indicating maintenance of response. Pregabalin CR was well tolerated in most patients. Generalizability may be limited by study duration and selective population.

Outcomes of switching directly to oral fingolimod from injectable therapies: Results of the randomized, open-label, multicenter, Evaluate Patient OutComes (EPOC) study in relapsing multiple sclerosis.

BACKGROUND: The Evaluate Patient OutComes (ClinicalTrials.gov Identifier: NCT01216072) study was conducted in North America to assess patient- and physician-reported treatment satisfaction in patients with relapsing multiple sclerosis (MS) who received oral fingolimod for 6 months after switching from an injectable disease-modifying therapy (iDMT), without an intervening washout. METHODS: In this open-label, multicenter study, patients were randomized 3:1 to once-daily fingolimod 0.5mg or iDMT. The primary study objective was to evaluate differences in satisfaction measured using the Treatment Satisfaction Questionnaire for Medication v1.4. RESULTS: Of 1053 patients randomized, 790 patients received fingolimod and 263 patients received iDMT. Treatment satisfaction improved significantly in patients who switched to fingolimod compared with those who continued iDMT. Patients also reported significant improvements in health-related quality of life, reduced depression, and reduced fatigue severity after a switch to fingolimod. No difference between the treatment groups was detected on the Patient Reported Indices for MS Activities scale. The safety profile of fingolimod was consistent with that reported in the pivotal phase 3 studies. The most commonly reported adverse events were more prevalent in patients who switched to fingolimod than in those who continued iDMT (headache: 12% vs 3%; fatigue: 12% vs 6%). No significant relationship between lymphocyte counts and infection rates was observed and there was no evidence of additive immune-system effects, which might be expected when switching to a different class of immunomodulatory therapy with no intervening washout. CONCLUSION: Patients who switched from iDMT to fingolimod had significant improvements in most self-reported outcomes compared with those who continued iDMT.

Pregabalin in patients with inadequately treated painful diabetic peripheral neuropathy: a randomized withdrawal trial.

OBJECTIVES: This study used a randomized withdrawal design to evaluate the efficacy of pregabalin versus placebo for pain relief in patients with painful diabetic peripheral neuropathy inadequately treated by other therapies. METHODS: A total of 665 patients received pregabalin in a 6-week single-blind phase. Two hundred ninety-four patients who achieved a ≥ 30% pain response were randomized to receive pregabalin or placebo in a double-blind phase for a further 13 weeks. The primary endpoint was the change in mean pain score from single-blind baseline to double-blind endpoint for pregabalin versus placebo (last observation carried forward [LOCF]). Secondary endpoints included a baseline observation carried forward (BOCF) analysis of mean pain score; time to loss of pain response; and other assessments of pain, sleep, function, and quality of life (QOL). RESULTS: Pregabalin numerically improved all measures assessed during the single-blind phase. At the end of the double-blind withdrawal phase, there was no significant difference in the primary endpoint of mean pain score (LOCF) between pregabalin and placebo (least squares mean difference, -0.32), although there was a significant difference in the BOCF analysis (least squares mean difference, -0.51). Pregabalin was associated with a significantly longer time to loss of pain response versus placebo during double-blind treatment, and some aspects of sleep and QOL also showed significant improvements with pregabalin. DISCUSSION: This is the first reported placebo-controlled trial of pregabalin in patients with inadequately treated painful diabetic peripheral neuropathy. Although the primary endpoint was not met, pregabalin was associated with clinically relevant improvements versus placebo in this difficult-to-treat population.