Effect size varies based on calculation method and may affect interpretation of treatment effect: an illustration using randomised clinical trials in osteoarthritis.

BACKGROUND: To illustrate how (standardised) effect sizes (ES) vary based on calculation method and to provide considerations for improved reporting. METHODS: Data from three trials of tanezumab in subjects with osteoarthritis were analyzed. ES of tanezumab versus comparator for WOMAC Pain (outcome) was defined as least squares difference between means (mixed model for repeated measures analysis) divided by a pooled standard deviation (SD) of outcome scores. Three approaches to computing the SD were evaluated: Baseline (the pooled SD of WOMAC Pain values at baseline [pooled across treatments]); Endpoint (the pooled SD of these values at the time primary endpoints were assessed); and Median (the median pooled SD of these values based on the pooled SDs across available timepoints). Bootstrap analyses were used to compute 95% confidence intervals (CI). RESULTS: ES (95% CI) of tanezumab 2.5 mg based on Baseline, Endpoint, and Median SDs in one study were - 0.416 (- 0.796, - 0.060), - 0.195 (- 0.371, - 0.028), and - 0.196 (- 0.373, - 0.028), respectively; negative values indicate pain improvement. This pattern of ES differences (largest with Baseline SD, smallest with Endpoint SD, Median SD similar to Endpoint SD) was consistent across all studies and doses of tanezumab. CONCLUSION: Differences in ES affect interpretation of treatment effect. Therefore, we advocate clearly reporting individual elements of ES in addition to its overall calculation. This is particularly important when ES estimates are used to determine sample sizes for clinical trials, as larger ES will lead to smaller sample sizes and potentially underpowered studies. TRIAL REGISTRATION: Clinicaltrials.gov NCT02697773, NCT02709486, and NCT02528188.

The relationship between weight gain during chemotherapy and outcomes in patients with advanced non-small cell lung cancer.

BACKGROUND: This post hoc, pooled analysis examined the relationship between different weight gain categories and overall survival (OS) in patients with non-small cell lung cancer (NSCLC) receiving first-line platinum-based chemotherapy. METHODS: Data were pooled from the control arms of three phase III clinical studies (NCT00596830, NCT00254891, and NCT00254904), and the maximum weight gain in the first 3 months from treatment initiation was categorised as >0%, >2.5%, and >5.0%. Cox proportional hazard modelling of OS was used to estimate hazard ratios (HRs) for each category, including baseline covariates, time to weight gain, and time to confirmed objective response (RECIST Version 1.0). RESULTS: Of 1030 patients with advanced NSCLC (IIIB 11.5% and IV 88.5%), 453 (44.0%), 252 (24.5%), and 120 (11.7%) experienced weight gain from baseline of >0%, >2.5%, and >5.0%, respectively. The median time to weight gain was 23 (>0%), 43 (>2.5%), and 45 (>5.0%) days. After adjusting for a time-dependent confirmed objective response, the risk of death was reduced for patients with any weight gain (>0% vs. ≤0% [HR 0.71; 95% confidence interval-CI 0.61, 0.82], >2.5% vs. ≤2.5% [HR 0.76; 95% CI 0.64, 0.91] and >5.0% vs. ≤5.0% [HR 0.77; 95% CI 0.60, 0.99]). The median OS was 13.5 versus 8.6 months (weight gain >0% vs. ≤0%), 14.4 versus 9.4 months (weight gain >2.5% vs. ≤2.5%), and 13.4 versus 10.2 months (weight gain >5.0% vs. ≤5.0%). CONCLUSIONS: Weight gain during treatment was associated with a reduced risk of death, independent of tumour response. The survival benefit was comparable for weight gain >0%, >2.5%, and >5.0%, suggesting that any weight gain may be an early predictor of survival with implications for the design of interventional cancer cachexia studies.

Effect size varies based on calculation method and may affect interpretation of treatment effect: an illustration using randomised clinical trials in osteoarthritis

Abstract Background To illustrate how (standardised) effect sizes (ES) vary based on calculation method and to provide considerations for improved reporting. Methods Data from three trials of tanezumab in subjects with osteoarthritis were analyzed. ES of tanezumab versus comparator for WOMAC Pain (outcome) was defined as least squares difference between means (mixed model for repeated measures analysis) divided by a pooled standard deviation (SD) of outcome scores. Three approaches to computing the SD were evaluated: Baseline (the pooled SD of WOMAC Pain values at baseline [pooled across treatments]); Endpoint (the pooled SD of these values at the time primary endpoints were assessed); and Median (the median pooled SD of these values based on the pooled SDs across available timepoints). Bootstrap analyses were used to compute 95% confidence intervals (CI). Results ES (95% CI) of tanezumab 2.5 mg based on Baseline, Endpoint, and Median SDs in one study were - 0.416 (- 0.796, - 0.060), - 0.195 (- 0.371, - 0.028), and - 0.196 (- 0.373, - 0.028), respectively; negative values indicate pain improvement. This pattern of ES differences (largest with Baseline SD, smallest with Endpoint SD, Median SD similar to Endpoint SD) was consistent across all studies and doses of tanezumab. Conclusion Differences in ES affect interpretation of treatment effect. Therefore, we advocate clearly reporting individual elements of ES in addition to its overall calculation. This is particularly important when ES estimates are used to determine sample sizes for clinical trials, as larger ES will lead to smaller sample sizes and potentially underpowered studies. Trial Registration Clinicaltrials.gov NCT02697773, NCT02709486, and NCT02528188.

Examining the Relationships Among Treatment, Pain, and Physical Function in Patients With Osteoarthritis: A Mediation-Modeling Approach.

OBJECTIVES: To better understand the relationships among treatment, pain, and physical function (PF). METHODS: Data were collected from 2 published randomized clinical trials of osteoarthritis patients who received tanezumab or a placebo. PF was measured by the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) PF domain. Pain (WOMAC pain domain) was a mediator of the effect of treatment on PF. A set of mediation models were investigated. Variables were treatment (tanezumab vs placebo), WOMAC pain domain, and WOMAC PF domain. Cross-sectional mediation models were assessed separately at different weeks. Longitudinal mediation models used data from all weeks simultaneously. Results could identify a steady-state period. RESULTS: The cross-sectional and longitudinal mediation models showed a stable indirect effect of treatment through the pain on PF across time, indicating that a pseudo-steady-state model was appropriate. Therefore, the longitudinal steady-state mediation models were used with all available data assuming relationships among variables in the model being the same at all time points; results showed that the indirect effect of the treatment on PF was 77.8% in study 1 (NCT02697773) and 74.1% in study 2 (NCT02709486), both P <0.0001, whereas the direct effect was 22.2% for study 1 ( P = 0.0003) and 25.9% for study 2 ( P = 0.0019). DISCUSSION: At least 75% of the treatment effect of tanezumab on physical functioning can be explained by the improvements in pain. However, tanezumab had an additional effect on physical functioning (~25%) that, was independent of improvements in pain. Such independent effects are of considerable interest and require further research to determine their mechanisms.

Efficacy and safety of tanezumab, NSAIDs, and placebo in patients with moderate to severe hip or knee osteoarthritis and a history of depression, anxiety, or insomnia: post-hoc analysis of phase 3 trials.

Objective: Treatment outcomes for chronic pain can be poor in patients with depression, anxiety, or insomnia. This analysis evaluated the efficacy and safety of subcutaneous tanezumab, nonsteroidal anti-inflammatory drugs (NSAIDs), and placebo in patients with osteoarthritis (OA) and a history of these conditions using data from three phase 3 studies.Methods: A post-hoc analysis of data from two pooled placebo-controlled studies and one NSAID-controlled study of subcutaneous tanezumab. All patients had moderate to severe knee or hip OA that was inadequately controlled with standard-of-care analgesics. Efficacy outcomes were least-squares mean change from baseline to Week 16 in Western Ontario McMaster Universities OA Index (WOMAC) Pain, WOMAC Physical Function, Patient's global assessment of OA, and EQ-5D-5L scores. Results were summarized for patients with and without a history of depression, anxiety, or insomnia at baseline.Results: 1545 patients were treated in the pooled placebo-controlled studies (history of depression, 12%; anxiety, 8%; insomnia, 10%; any, 23%) and 2996 in the NSAID-controlled study (16%, 11%, 13%, 28%, respectively). In groups with positive histories, 38-80% took antidepressant or anxiolytic medications at baseline. Within treatments, largely similar improvements in efficacy outcomes were observed in patients with and without a history of depression, anxiety, or insomnia; the types of treatment-emergent adverse events were similar.Conclusions: Patients with OA and a history of depression, anxiety, or insomnia did not appear to experience reduced efficacy outcomes or an altered safety profile in response to tanezumab or NSAID treatment as compared with those without. NCT02697773; NCT02709486; NCT02528188.

Clinical Meaningfulness of Response to Tanezumab in Patients with Chronic Low Back Pain: Analysis From a 56-Week, Randomized, Placebo- and Tramadol-Controlled, Phase 3 Trial.

INTRODUCTION: A recent phase 3, randomized, placebo- and tramadol-controlled trial (56-week treatment/24-week safety follow-up) demonstrated efficacy of tanezumab 10 mg in patients with chronic low back pain (CLBP) and a history of inadequate response to standard-of-care analgesics. Here, we report on the clinical meaningfulness of treatment response in this study, focused on secondary measures of pain, interference with daily functions, overall disease status, and satisfaction with treatment. METHODS: Patients received placebo (up to week 16; n = 406), subcutaneously administered (SC) tanezumab 5 mg (every 8 weeks; n = 407), SC tanezumab 10 mg (every 8 weeks; n = 407), or orally administered tramadol prolonged-release (100-300 mg/day; n = 605) for 56 weeks. Patient's global assessment of low back pain (PGA-LBP), Brief Pain Inventory-short form (BPI-sf), Treatment Satisfaction Questionnaire for Medication (TSQM), and modified Patient-Reported Treatment Impact (mPRTI) were assessed at weeks 16 and 56. RESULTS: At week 16, significant (p < 0.05) improvements over placebo were evident with tanezumab for the PGA-LBP (10 mg) and most BPI-sf (both doses), TSQM (both doses), and mPRTI (both doses) items assessed. Improvements over baseline persisted for the PGA-LBP and BPI-sf at week 56. However, the magnitude of improvements was modestly lower at week 56 relative to week 16. Tramadol did not improve PGA-LBP or BPI-sf scores versus placebo at week 16. Most differences between tanezumab and tramadol at week 56 did not reach the level of statistical significance for all endpoints. CONCLUSIONS: The totality of the evidence as captured by measures of pain, interference with daily function, patient overall assessment of disease status, and satisfaction with treatment demonstrates the clinically meaningful benefit of tanezumab for some patients with CLBP compared with placebo. CLINICALTRIALS: gov: NCT02528253.

Gender, age, disease severity, body mass index and diabetes may not affect response to subcutaneous tanezumab in patients with osteoarthritis after 16 weeks of treatment. A subgroup analysis of placebo-controlled trials.

AIM: To assess the impact of pre-specified patient characteristics on efficacy and safety of subcutaneous tanezumab in patients with osteoarthritis (OA). METHODS: Data were pooled from two (efficacy; N = 1545) or three (safety; N = 1754) phase 3 placebo-controlled trials. Change from baseline to week 16 in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) Pain, WOMAC Physical Function and patient global assessment of OA (PGA-OA) scores was compared between tanezumab (2.5 and 5 mg) and placebo groups via analysis of covariance. Treatment-emergent adverse events (TEAEs) were summarised descriptively. Analyses were done in patient subgroups (men or women; age <65, ≥65, or ≥75 years; body mass index [BMI] <25, 25 to <30, 30 to <35 or ≥35 kg/m2 ; diabetes or no diabetes; baseline WOMAC Pain score <7 or ≥7; and Kellgren-Lawrence [KL] grades 2, 3 or 4 in the index joint) and the overall population. RESULTS: In all subgroups, improvements in WOMAC Pain were numerically greater and often statistically significant (P < .05) for both tanezumab groups compared with placebo. Results were similar for WOMAC Physical Function and PGA-OA. TEAE profiles were generally consistent across subgroups and similar to the overall population (ie slightly higher rates of TEAEs, serious TEAEs and severe TEAEs with tanezumab relative to placebo) with a few exceptions. Exceptions included women reporting slightly more TEAEs with tanezumab than men, and patients with diabetes reporting slightly more severe TEAEs with tanezumab than patients without diabetes. Additionally, TEAEs were more frequent with tanezumab than placebo in the age ≥65 and ≥75 years, but not the age <65 years, subgroups. CONCLUSIONS: Efficacy and safety/tolerability of tanezumab may not be meaningfully impacted by gender, age, BMI, diabetes status, baseline pain severity or KL grade in the index joint. Conclusions are limited by low patient number in some subgroups. Clinicaltrials.gov: NCT02697773, NCT02709486, NCT01089725.

Single and Composite Endpoints of Within-Patient Improvement in Symptoms: Pooled Tanezumab Data in Patients with Osteoarthritis.

INTRODUCTION: Combining measures of key core domains (especially pain and function) into a composite endpoint that requires each patient to meet a threshold of improvement for each domain provides information on multiple aspects of osteoarthritis within individual patients. This pooled analysis of two phase 3 studies (NCT02697773, NCT02709486) explored single and composite endpoints for assessing within-patient improvement in knee or hip osteoarthritis symptoms following subcutaneous administration of tanezumab or placebo. METHODS: Endpoints at week 16 included proportions of responders (≥ 30% improvement) in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) Pain, WOMAC Physical Function, WOMAC Pain/Function composite, and weekly average pain; and patient acceptable symptom state (PASS) composite responders, minimal clinically important improvement (MCII) composite responders, Outcome Measures in Rheumatology-Osteoarthritis Research Society International (OMERACT-OARSI) responders, and sustained weekly average pain responders. RESULTS: Pooled population comprised 1545 patients. Of patients who had a ≥ 30% improvement in WOMAC Pain and/or WOMAC Physical Function, 88.5% were WOMAC Pain/Function composite responders, 7.0% were WOMAC Pain (but not Function) responders, and 4.4% were WOMAC Function (but not Pain) responders. Of weekly average pain responders, 43.1% were PASS composite responders. Odds ratios (tanezumab 2.5 mg and 5 mg groups, respectively, vs placebo) were 1.75 and 1.86 (WOMAC Pain/Function composite responders), 1.41 and 1.65 (weekly average pain responders), 1.60 and 1.73 (PASS composite responders), 1.52 and 1.68 (MCII composite responders), 1.75 and 1.88 (OMERACT-OARSI responders), and 1.85 and 1.48 (sustained weekly average pain responders). Subgroup analyses suggested a greater magnitude of effect for patients with a knee index joint compared with hip on some endpoints. CONCLUSION: Responders on single pain endpoints were in many cases also responders on function or composite endpoints. Separation of tanezumab from placebo was similar and consistent across single and composite endpoints.

Pregabalin adjunctive therapy for focal onset seizures in children 1 month to <4 years of age: A double-blind, placebo-controlled, video-electroencephalographic trial.

OBJECTIVE: To evaluate the efficacy and safety of pregabalin as adjunctive treatment for children (aged 1 month-<4 years) with focal onset seizures (FOS) using video-electroencephalography (V-EEG). METHODS: This randomized, placebo-controlled, international study included V-EEG seizure monitoring (48-72 hours) at baseline and over the last 3 days of 14-day (5-day dose escalation; 9-day fixed dose) double-blind pregabalin treatment (7 or 14 mg/kg/d in three divided doses). This was followed by a double-blind 1-week taper. The primary efficacy endpoint was log-transformed seizure rate (loge [24-hour seizure rate + 1]) for all FOS recorded during the double-blind V-EEG monitoring, evaluated in subjects who took ≥1 dose of study medication, experienced ≥1 baseline seizure(s), and had a treatment phase V-EEG. Safety and tolerability were assessed by adverse events (AEs), clinical laboratory data, physical/neurological examinations, vital signs, and electrocardiograms. RESULTS: Overall, 175 patients were randomized (mean age = 28.2 months; 59% male, 69% white, 30% Asian) in a 2:1:2 ratio to pregabalin 7 or 14 mg/kg/d (n = 71 or n = 34, respectively), or placebo (n = 70). Pregabalin 14 mg/kg/d (n = 28) resulted in a statistically significant 35% reduction of loge (24-hour seizure rate + 1) versus placebo (n = 53; P = .022), an effect that was not observed with pregabalin 7 mg/kg/d (n = 59; P = .461). The most frequently reported treatment-emergent AEs for pregabalin 7 mg/kg/d, 14 mg/kg/d, and placebo, respectively, were somnolence (11.3%, 17.6%, and 5.7%) and upper respiratory tract infection (7.0%, 11.8%, and 11.4%). All AEs were mild to moderate in severity. SIGNIFICANCE: Pregabalin 14 mg/kg/d (but not 7 mg/kg/d) significantly reduced seizure rate in children with FOS, when assessed using V-EEG, compared with placebo. Both pregabalin dosages were generally safe and well tolerated in children 1 month to <4 years of age with FOS. Safety and tolerability were consistent with the known profile of pregabalin in older children with epilepsy.

Efficacy of pregabalin in post-traumatic peripheral neuropathic pain: a randomized, double-blind, placebo-controlled phase 3 trial.

The growing need for symptomatic treatment of post-traumatic neuropathic pain (PTNP) continues to be unmet. Studies evaluating the efficacy of pregabalin for reducing neuropathic pain following trauma and surgery yielded positive results over ≤ 8-week treatment. To assess the efficacy and tolerability of pregabalin over 3 months in patients with PTNP, a randomized, double-blind, placebo-controlled, parallel-group trial evaluated patients with PTNP at 101 centers in 11 countries-the longest, largest such trial. Adults diagnosed with PTNP were randomly assigned (1:1) to 15 weeks of pregabalin (flexibly dosed 150-600 mg/day) or matching placebo. Primary efficacy analysis was by mixed-model repeated measures comparing change from baseline to week 15 in weekly mean pain scores between active and placebo groups. Evaluable patients included 274 in the pregabalin group and 265 in the placebo group. Trauma was surgical in 49.6% of patients, non-surgical in the remainder. The primary efficacy analysis showed no statistically significant difference between pregabalin and placebo groups in the change from baseline to week 15 [mean difference, - 0.22 points (95% confidence interval, 0.54-0.10); p = 0.1823]. However, comparisons for key secondary outcome measures yielded p values < 0.05 favoring pregabalin. Consistent with the known safety profile of pregabalin, the most common adverse events were dizziness and somnolence (14.6 and 9.9% of patients, respectively) with pregabalin (vs 4.2 and 3.4% with placebo). These findings demonstrate the feasibility of conducting a large, phase 3 registration trial in the heterogeneous PTNP study population.ClinicalTrials.gov NCT01701362.

Efficacy and safety of pregabalin for painful diabetic peripheral neuropathy in a population of Chinese patients: A randomized placebo-controlled trial.

BACKGROUND: Limited information exists regarding the efficacy of pregabalin in Chinese patients with painful diabetic peripheral neuropathy (pDPN). METHODS: An 11-week double-blind placebo-controlled trial was performed in Chinese pDPN patients randomized (1 : 1) to 300 mg/day pregabalin or placebo. The primary outcome was change from baseline to endpoint in mean pain score (MPS; 0, no pain; 10, worst possible pain; using the mean of the last seven daily pain scores). Secondary outcomes included weekly MPS and responder status (MPS reduced by ≥30% or ≥50% vs baseline). Subgroup analysis assessed patients with severe (≥7) baseline MPS. Adverse events (AEs) were reported. RESULTS: In all, 620 patients were randomized (pregabalin, n = 313; placebo, n = 307). Improvement in MPS with pregabalin versus placebo was not significant (P = 0.0559). Post hoc sensitivity analyses, excluding one patient/site due to Good Clinical Practice (GCP) non-compliance, showed pregabalin significantly improved MPS when excluding the patient (P = 0.0448) or site (P = 0.0142). Pregabalin significantly improved weekly MPS (P = 0.0164) and ≥50% responders at endpoint (P = 0.0384). Improvement in proportion of ≥30% responders, impression of change, pain intensity, and sleep did not differ significantly between the treatment groups. In the severe pDPN subpopulation, pregabalin significantly improved MPS versus placebo (P = 0.0040). The most commonly reported AE was dizziness (9.6% vs 3.9% with placebo). CONCLUSIONS: Pregabalin did not significantly improve the primary measure of pain in the trial. Significant reductions in MPS were observed when excluding the GCP non-compliant patient/site and in the severe pDPN subpopulation. Pregabalin was well tolerated in Chinese pDPN patients.

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.

Pregabalin for the treatment of postoperative pain: results from three controlled trials using different surgical models.

PURPOSE: To evaluate the efficacy and safety of pregabalin (150 or 300 mg/d) as an adjunctive therapy for the treatment of postoperative pain. PATIENTS AND METHODS: This study reports findings from three separate, multicenter, randomized, double-blind, placebo-controlled trials of adjunctive pregabalin for the treatment of postoperative pain. Patients underwent one of three categories of surgical procedures (one procedure per study): elective inguinal hernia repair (post-IHR); elective total knee arthroplasty (post-TKA); or total abdominal hysterectomy (posthysterectomy). The primary endpoint in each trial, mean worst pain over the past 24 hours, was assessed 24 hours post-IHR and posthysterectomy, and 48 hours post-TKA. Patients rated their pain on a scale from 0 to 10, with higher scores indicating greater pain severity. RESULTS: In total, 425 (post-IHR), 307 (post-TKA), and 501 (posthysterectomy) patients were randomized to treatment. There were no statistically significant differences between the pregabalin and placebo groups with respect to the primary endpoint in any of the three trials. The least squares mean difference in worst pain, between 300 mg/d pregabalin and placebo, was -0.7 (95% confidence interval [CI] =-1.4, -0.1; Hochberg adjusted P=0.067) post-IHR; -0.34 (95% CI =-1.07, 0.39; P=0.362) post-TKA; and -0.2 (95% CI =-0.66, 0.31; P=0.471) posthysterectomy. CONCLUSION: There were no significant differences between pregabalin and placebo with respect to the primary pain intensity measure in each of the three clinical trials. These studies encompass a large dataset (1,233 patients in total), and their results should be considered when assessing pregabalin's effectiveness in postoperative pain. Further studies are required to determine the potential pain-reducing benefit of pregabalin in the postoperative setting.

Efficacy and safety of pregabalin in patients with spinal cord injury: a pooled analysis.

OBJECTIVE: To summarize the efficacy and examine the safety and tolerability of pregabalin in patients with central neuropathic pain due to spinal cord injury (SCI). RESEARCH DESIGN AND METHODS: Data were pooled from two 12 to 16 week, placebo-controlled trials of pregabalin in patients with neuropathic pain due to SCI. Pain diaries were used to rate pain from 0 = no pain to 10 = worst possible pain. Efficacy measures included: mean change in pain from baseline to endpoint; duration adjusted average change (DAAC) in pain; the percentage of patients with ≥30% or ≥50% reductions in pain score from baseline to endpoint; and Patient Global Impression of Change (PGIC) score at endpoint. Adverse events (AEs) were also compared between treatment groups. RESULTS: In total 174 patients received placebo and 182 received pregabalin. Mean change in pain from baseline to endpoint was improved in the pregabalin group compared with placebo (placebo-adjusted difference = -0.79; 95% CI = -1.15, -0.43; p < 0.001; baseline-observation-carried-forward). DAAC in pain was improved in patients receiving pregabalin compared with placebo (p < 0.001). The percentage of patients achieving ≥30% and ≥50% reductions in pain from baseline to endpoint was greater in the pregabalin arm compared with placebo (placebo: 30% = 22.5%, 50% = 11.6: pregabalin 30% = 35.6%, 50% = 22.4%) (all p < 0.01). PGIC scores at endpoint were significantly better in the pregabalin arm compared with placebo (p < 0.05). Treatment-related AEs, most commonly somnolence, dizziness, dry mouth, fatigue, edema, blurred vision, and constipation occurred more frequently in patients treated with pregabalin than placebo. The majority of AEs were mild to moderate in severity. CONCLUSIONS: Pregabalin reduced neuropathic pain due to SCI over a 12 to 16 week treatment period. Treatment-related AEs were mostly mild to moderate in severity and are consistent with the known safety profile of pregabalin. These findings should not be extrapolated to longer durations of treatment or other patient populations.

A randomized trial of pregabalin in patients with neuropathic pain due to spinal cord injury.

OBJECTIVE: To assess the efficacy and tolerability of pregabalin for the treatment of central neuropathic pain after spinal cord injury (SCI). METHODS: Patients with chronic, below-level, neuropathic pain due to SCI were randomized to receive 150 to 600 mg/d pregabalin (n = 108) or matching placebo (n = 112) for 17 weeks. Pain was classified in relation to the neurologic level of injury, defined as the most caudal spinal cord segment with normal sensory and motor function, as above, at, or below level. The primary outcome measure was duration-adjusted average change in pain. Key secondary outcome measures included the change in mean pain score from baseline to end point, the percentage of patients with ≥30% reduction in mean pain score at end point, patient global impression of change scores at end point, and the change in mean pain-related sleep interference score from baseline to end point. Additional outcome measures included the medical outcomes study-sleep scale and the Hospital anxiety and depression scale. RESULTS: Pregabalin treatment resulted in statistically significant improvements over placebo for all primary and key secondary outcome measures. Significant pain improvement was evident as early as week 1 and was sustained throughout the treatment period. Adverse events were consistent with the known safety profile of pregabalin and were mostly mild to moderate in severity. Somnolence and dizziness were most frequently reported. CONCLUSIONS: This study demonstrates that pregabalin is effective and well tolerated in patients with neuropathic pain due to SCI. CLASSIFICATION OF EVIDENCE: This study provides class I evidence that pregabalin, 150 to 600 mg/d, is effective in reducing duration-adjusted average change in pain compared with baseline in patients with SCI over a 16-week period (p = 0.003, 95% confidence interval = -0.98, -0.20).

Randomized study of pregabalin in patients with cancer-induced bone pain.

INTRODUCTION: Improvements are needed in the management of cancer-induced bone pain (CIBP). The objective of this study was to assess the efficacy and safety of pregabalin compared with placebo in the adjunctive treatment of patients with moderate to severe CIBP who were receiving opioids. METHODS: In this randomized, double-blind, placebo-controlled, parallel-group, multicenter trial, 152 adults diagnosed with a malignant, solid tumor with metastases to bone were randomized to flexible-dose pregabalin (100, 150, 300, or 600 mg/day) or placebo, as add-on to stable opioid analgesic therapy, which was optimized prior to the start of the study. The primary efficacy endpoint was the duration-adjusted average change (DAAC) from baseline in the daily worst pain at the reference site (measured by 11-point numeric rating scale [NRS]) during the fixed-dosage phase. The study was terminated early following an interim analysis that indicated an increase in sample size would be needed to satisfy statistical assumptions for the primary endpoint. Given the early termination of the study, only descriptive analyses were performed. RESULTS: The mean (standard deviation) DAAC from baseline in NRS score for the primary endpoint favored pregabalin treatment: -1.53 (1.81) in the pregabalin group and -1.23 (1.74) in the placebo group. Mean DAAC for average pain and sleep interference (NRS) also favored pregabalin. More patients treated with pregabalin reported improvement ("very much improved," "much improved," or "minimally improved") based on Patient Global Impression of Change: 81.4% compared with 70.0% in the placebo group. CONCLUSION: Data from this study indicate that pregabalin use may reduce metastatic bone pain. Due to the incomplete analysis, further study of pregabalin in the management of CIBP is required.

Two 6-week, randomized, double-blind, placebo-controlled studies of ziprasidone in outpatients with bipolar I depression: did baseline characteristics impact trial outcome?

Two randomized, double-blind, placebo-controlled, 6-week studies comparing ziprasidone versus placebo for treatment of bipolar depression (BPD) failed to meet their primary study objectives, indicating that either ziprasidone is ineffective in the treatment of BPD or the study failed. Adult outpatients with bipolar I depression with 17-item Hamilton Rating Scale for Depression total score more than 20 at screening and baseline received either ziprasidone 40 to 80 mg/d, 120 to 160 mg/d, or placebo (study 1), or ziprasidone 40 to 160 mg/d or placebo (study 2). Primary efficacy measure in both studies was change from baseline in Montgomery-Åsberg Depression Rating Scale total scores at week 6 (end of the study). Mixed-model repeated-measures methodology was used to analyze the primary efficacy measure in both studies. Secondary efficacy measures in both studies included Hamilton Rating Scale for Depression total score and Clinical Global Impression-Improvement score. Post hoc analyses were conducted for both studies to examine potential reasons for study failure. In both, ziprasidone treatment groups failed to separate statistically from placebo for change from baseline Montgomery-Åsberg Depression Rating Scale score at week 6. Response rates were 49%, 53%, and 46% for placebo, ziprasidone 40 to 80 mg/d, and ziprasidone 120 to 160 mg/d, respectively (study 1), and 51% and 53% for placebo and ziprasidone 40 to 160 mg/d, respectively (study 2). Ziprasidone 40 to 160 mg/d did not show superiority over placebo at week 6 in the treatment of BPD. Post hoc analyses revealed serious inconsistencies in subject rating that may have limited the ability to detect a difference between drug and placebo response. Rating reliability warrants further investigation to improve clinical trial methodology in psychiatry.

Sertraline treatment of children and adolescents with posttraumatic stress disorder: a double-blind, placebo-controlled trial.

OBJECTIVE: The aim of this study was to evaluate the safety and efficacy of sertraline in children and adolescents who met Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) criteria for posttraumatic stress disorder (PTSD). METHOD: Children and adolescents (6-17 years old) meeting DSM-IV criteria for PTSD were randomized to 10 weeks of double-blind treatment with sertraline (50-200 mg/day) or placebo. The primary efficacy measure was the University of California, Los Angeles Post-Traumatic Stress Disorder Index for DSM-IV (UCLA PTSD-I). RESULTS: A total of 131 patients met entry criteria and were randomized to sertraline (n = 67; female, 59.7%; mean age, 10.8; mean UCLA PTSD-I score, 43.8 ± 8.5) or placebo (n = 62; female, 61.3%; mean age, 11.2; mean UCLA PTSD-I score, 42.1 ± 8.8). There was no difference between sertraline and placebo in least squares (LS) mean change in the UCLA PTSD-I score, either on a completer analysis (-20.4 ± 2.1 vs. -22.8 ± 2.1; p = 0.373) or on an last observation carried forward (LOCF) end point analysis (-17.7 ± 1.9 vs. -20.8 ± 2.1; p = 0.201). Attrition was higher on sertraline (29.9%) compared to placebo (17.7%). Discontinuation due to adverse events occurred in a 7.5% treated with sertraline and 3.2% treated with placebo. CONCLUSIONS: Sertraline was a generally safe treatment in children and adolescents with PTSD, but did not demonstrate efficacy when compared to placebo during 10 weeks of treatment. ClinicalTrials.gov Identifier: NCT00150306.

Effect of ziprasidone dose on all-cause discontinuation rates in acute schizophrenia and schizoaffective disorder: a post-hoc analysis of 4 fixed-dose randomized clinical trials.

BACKGROUND: Higher dose ziprasidone has been associated with improved treatment outcomes in patients with schizophrenia or schizoaffective disorder. This study examines the relationship of ziprasidone dose and all-cause discontinuation in randomized clinical trials in patients with an acute exacerbation of schizophrenia or schizoaffective disorder. METHOD: Data were analyzed for the first 28 days from 4 pivotal, randomized, double-blind, fixed-dose ziprasidone trials. Patients in these trials had a DSM-IV diagnosis of schizophrenia or schizoaffective disorder where ziprasidone was administered twice daily with food. Data were analyzed to examine the association between ziprasidone dose and all-cause discontinuation due to lack of efficacy, adverse events, or because of other reasons, relative to placebo. Differences in discontinuation were evaluated using Cox proportional hazard models and number needed to treat (NNT). RESULTS: All-cause discontinuation for ziprasidone ranged from a low of 26.9% for the 160 mg/d dose group, to 40.9% for the 40 mg/d and 45.5% for the 80 mg/d groups, compared with 49.5% for placebo. The NNTs for avoiding 1 additional all-cause discontinuation compared with placebo were 12 (40 mg/d; n=186), 25 (80 mg/d; n=154), 9 (120 mg/d; n=125), and 4 (160 mg/d; n=104). The 120 mg/d and 160 mg/d groups were the only ziprasidone regimens associated with significantly lower all-cause discontinuation rates versus placebo in both the survival analysis (p=0.031 and <0.0001, respectively) and in examination of the NNT. The 160 mg/d group was associated with lower all-cause discontinuation rates versus lower-dose ziprasidone regimens (p=0.0158 for versus 40 mg/d, p=0.002 for versus 80 mg/d). Efficacy accounted for 51% of all medication discontinuations across ziprasidone groups, compared with 62% for placebo. Findings for overall discontinuation due to lack of efficacy are consistent with results for all-cause discontinuation. CONCLUSIONS: Consistent with previous reports, higher doses of ziprasidone (120-160 mg/d, dosed twice daily with meals) are associated with significantly lower all-cause discontinuation rates and more favorable NNTs versus placebo. This was primarily driven by lower rates of discontinuation due to lack of efficacy.