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How should we design future mechanistic and/or efficacy clinical trials?

The emergence of new molecular targets, together with the development of new approaches to neuropsychiatric diseases, involving psychedelics as well as gene and cell therapies, are creating the need to improve the efficiency of mechanistic and/or efficacy clinical trials. This review article will discuss a number of issues that have hampered our ability to detect therapeutic signals, from excessive placebo/sham response rates to the imprecision of diagnostic and outcome assessments. In addition to reviewing the limitations of current efficacy and mechanistic neuropsychiatric clinical trials, this review presents some of the methodological approaches that may improve the overall performance of our neuropsychiatric trials, including the adoption of novel study designs such as the sequential parallel comparison design and independent confirmation of the appropriateness of subjects' enrollment. In addition, this review will discuss several designs that make mechanistic clinical trials more precise.

Effect of AXS-05 (Dextromethorphan-Bupropion) in Major Depressive Disorder: A Randomized Double-Blind Controlled Trial

OBJECTIVE

Altered glutamatergic neurotransmission is implicated in the pathogenesis of major depressive disorder. AXS-05 (dextromethorphan-bupropion) is an oral NMDA receptor antagonist and sigma-1 receptor agonist, which utilizes inhibition of CYP2D6 to increase its bioavailability. This phase 2 trial assessed the efficacy and safety of dextromethorphan-bupropion in the treatment of major depressive disorder.

METHODS

This randomized, double-blind, multicenter, parallel-group trial evaluated dextromethorphan-bupropion versus the active comparator sustained-release bupropion in patients 18-65 years old with a diagnosis of major depressive disorder of moderate or greater severity. Patients were randomly assigned to receive either dextromethorphan-bupropion (45 mg/105 mg tablet) or bupropion (105 mg tablet), once daily for the first 3 days and twice daily thereafter, for a total of 6 weeks. The primary endpoint was overall treatment effect on Montgomery-Åsberg Depression Rating Scale (MADRS) score (average of the change from baseline for weeks 1-6), assessed in all randomized patients whose diagnosis and severity were confirmed by an independent assessor and who received at least one dose of study medication and had at least one postbaseline assessment.

RESULTS

Of 97 patients randomized, 17 did not have a confirmed diagnosis and severity based on the independent assessment, resulting in 80 patients in the efficacy population (dextromethorphan-bupropion, N=43; bupropion, N=37). The mean change from baseline in MADRS score over weeks 1-6 (overall treatment effect) was significantly greater with dextromethorphan-bupropion than with bupropion (-13.7 points vs. -8.8 points; least-squares mean difference=-4.9; 95% CI=-3.1, -6.8). MADRS score change with dextromethorphan-bupropion was significantly greater than with bupropion at week 2 and every time point thereafter (week 6: -17.3 vs. -12.1 points; least-squares mean difference=-5.2, 95% CI=-1.1, -9.3). Remission rates were significantly greater with dextromethorphan-bupropion at week 2 and every time point thereafter (week 6: 46.5% vs. 16.2%; least-squares mean difference=30.3%, 95% CI=11.2, 49.4). Response rates (≥50% decrease in MADRS score from baseline) at week 6 were 60.5% with dextromethorphan-bupropion and 40.5% with bupropion (least-squares mean difference=19.9%, 95% CI=-1.6, 41). Most secondary outcomes favored dextromethorphan-bupropion. The most common adverse events with dextromethorphan-bupropion were dizziness, nausea, dry mouth, decreased appetite, and anxiety. Dextromethorphan-bupropion was not associated with psychotomimetic effects, weight gain, or sexual dysfunction.

CONCLUSIONS

In patients with major depression, dextromethorphan-bupropion (AXS-05) significantly improved depressive symptoms compared with bupropion and was generally well tolerated.

Impact of chosen cutoff on response rate differences between selective serotonin reuptake inhibitors and placebo

Response defined as a 50% reduction in the sum score of the Hamilton Depression Rating Scale (HDRS-17-sum) is often used to assess the efficacy of antidepressants. Critics have, however, argued that dichotomising ratings with a cutoff close to the median may lead to scores clustering on either side, the result being inflation of miniscule drug-placebo differences. Using pooled patient-level data sets from trials of three selective serotonin reuptake inhibitors (SSRIs) (citalopram, paroxetine and sertraline) (n = 7909), and from similar trials of duloxetine (n = 3478), we thus assessed the impact of different cutoffs on response rates. Response criteria were based on (i) HDRS-17-sum, (ii) the sum score of the HDRS-6 subscale (HDRS-6-sum) and (iii) the depressed mood item. The separation between SSRI and placebo with respect to response rates increased when HDRS-17-sum was replaced by HDRS-6-sum or depressed mood as effect parameter and was markedly dependent on SSRI dose. With the exception of extreme cutoff values, differences in response rates were largely similar regardless of where the cutoff was placed, and also not markedly changed by the exclusion of subjects close to the selected cutoff (e.g., ±10%). The observation of similar response rate differences between active drugs and placebo for different cutoffs was corroborated by the analysis of duloxetine data. In conclusion, the suggestion that using a cutoff close to the median when defining response has markedly overestimated the separation between antidepressants and placebo may be discarded.

One (effect) size does not fit at all: Interpreting clinical significance and effect sizes in depression treatment trials

The efficacy of antidepressants in major depressive disorder has been continually questioned, mainly on the basis of studies using the sum-score of the Hamilton Depression Rating Scale as a primary outcome parameter. On this measure antidepressants show a standardised mean difference of around 0.3, which some authors suggested is below the cut-off for clinical significance. Prompted by a recent review that, using this argument, concluded antidepressants should not be used for adults with major depressive disorder, we (a) review the evidence in support of the cut-off for clinical significance espoused in that article (a Hamilton Depression Rating Scale standardised mean difference of 0.875); (b) discuss the limitations of average Hamilton Depression Rating Scale sum-score differences between groups as measure of clinical significance; (c) explore alternative measures of clinical importance; and (d) suggest future directions to help overcome disagreements on how to define clinical significance. We conclude that (a) the proposed Hamilton Depression Rating Scale cut-off of 0.875 has no scientific basis and is likely misleading; (b) there is no agreed upon way of delineating clinically significant from clinically insignificant; (c) evidence suggests the Hamilton Depression Rating Scale sum-score underestimates antidepressant efficacy; and (d) future clinical trials should consider including measures directly reflective of functioning and wellbeing, in addition to measures focused on depression psychopathology.

Improving Study Conduct and Data Quality in Clinical Trials of Chronic Pain Treatments: IMMPACT Recommendations

The estimated probability of progressing from phase 3 analgesic clinical trials to regulatory approval is approximately 57%, suggesting that a considerable number of treatments with phase 2 trial results deemed sufficiently successful to progress to phase 3 do not yield positive phase 3 results. Deficiencies in the quality of clinical trial conduct could account for some of this failure. An Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials meeting was convened to identify potential areas for improvement in trial conduct in order to improve assay sensitivity (ie, ability of trials to detect a true treatment effect). We present recommendations based on presentations and discussions at the meeting, literature reviews, and iterative revisions of this article. The recommendations relate to the following areas: 1) study design (ie, to promote feasibility), 2) site selection and staff training, 3) participant selection and training, 4) treatment adherence, 5) data collection, and 6) data and study monitoring. Implementation of these recommendations may improve the quality of clinical trial data and thus the validity and assay sensitivity of clinical trials. Future research regarding the effects of these strategies will help identify the most efficient use of resources for conducting high quality clinical trials. PERSPECTIVE: Every effort should be made to optimize the quality of clinical trial data. This manuscript discusses considerations to improve conduct of pain clinical trials based on research in multiple medical fields and the expert consensus of pain researchers and stakeholders from academia, regulatory agencies, and industry.

Placebo-To be or not to be? Are there really alternatives to placebo-controlled trials?

Recent success of established treatment has driven concerns about the ethics of using placebo-controlled trials in psychiatry. Active-controlled (superiority or non-inferiority) trials do not include a placebo-arm and thus avoid the associated ethical concerns but show disadvantages in other respects. The aim of this paper is to review the available literature and critically discuss the evidence regarding the use of placebo-controlled- versus active-controlled trials. A MEDLINE/PubMed and Google Scholar search was performed. Studies included focused on the deliberation on placebo-controlled- versus active-controlled trials. Twenty-six studies were included. The most cited benefits of placebo-controlled trials were greater scientific reliability of the results and no average impact on patients' health. Disadvantages were mainly related to withholding effective treatment and limited generalizability. The most frequent argument in favor of active-controlled trials is the lower chance of receiving ineffective medication during the trial. Downsides include larger sample sizes, higher costs and lower scientific reliability of results. Most authors agree that all trial designs are relevant to psychiatric research depending on study goals. Whatsoever, data does not support forgoing placebo-controlled trials. Expert consensus is warranted to permit drawing conclusions on the debate on the relevance of placebo-controlled trials.

A meta-analysis of randomized, placebo-controlled trials of vortioxetine for the treatment of major depressive disorder in adults

The efficacy and safety of vortioxetine, an antidepressant approved for the treatment of adults with major depressive disorder (MDD), was studied in 11 randomized, double-blind, placebo-controlled trials of 6/8 weeks׳ treatment duration. An aggregated study-level meta-analysis was conducted to estimate the magnitude and dose-relationship of the clinical effect of approved doses of vortioxetine (5-20mg/day). The primary outcome measure was change from baseline to endpoint in Montgomery-Åsberg Depression Rating Scale (MADRS) total score. Differences from placebo were analyzed using mixed model for repeated measurements (MMRM) analysis, with a sensitivity analysis also conducted using last observation carried forward. Secondary outcomes included MADRS single-item scores, response rate (≥50% reduction in baseline MADRS), remission rate (MADRS ≤10), and Clinical Global Impressions scores. Across the 11 studies, 1824 patients were treated with placebo and 3304 with vortioxetine (5mg/day: n=1001; 10mg/day: n=1042; 15mg/day: n=449; 20mg/day: n=812). The MMRM meta-analysis demonstrated that vortioxetine 5, 10, and 20mg/day were associated with significant reductions in MADRS total score (Δ-2.27, Δ-3.57, and Δ-4.57, respectively; p<0.01) versus placebo. The effects of 15mg/day (Δ-2.60; p=0.105) were not significantly different from placebo. Vortioxetine 10 and 20mg/day were associated with significant reductions in 9 of 10 MADRS single-item scores. Vortioxetine treatment was also associated with significantly higher rates of response and remission and with significant improvements in other depression-related scores versus placebo. This meta-analysis of vortioxetine (5-20mg/day) in adults with MDD supports the efficacy demonstrated in the individual studies, with treatment effect increasing with dose.

Antidepressants versus placebo in major depression: an overview

Although the early antidepressant trials which included severely ill and hospitalized patients showed substantial drug-placebo differences, these robust differences have not held up in the trials of the past couple of decades, whether sponsored by pharmaceutical companies or non-profit agencies. This narrowing of the drug-placebo difference has been attributed to a number of changes in the conduct of clinical trials. First, the advent of DSM-III and the broadening of the definition of major depression have led to the inclusion of mildly to moderately ill patients into antidepressant trials. These patients may experience a smaller magnitude of antidepressant-placebo differences. Second, drug development regulators, such as the U.S. Food and Drug Administration and the European Medicines Agency, have had a significant, albeit underappreciated, role in determining how modern antidepressant clinical trials are designed and conducted. Their concerns about possible false positive results have led to trial designs that are poor, difficult to conduct, and complicated to analyze. Attempts at better design and patient selection for antidepressant trials have not yielded the expected results. As of now, antidepressant clinical trials have an effect size of 0.30, which, although similar to the effects of treatments for many other chronic illnesses, such as hypertension, asthma and diabetes, is less than impressive.

A randomized, double-blind, duloxetine-referenced study comparing efficacy and tolerability of 2 fixed doses of vortioxetine in the acute treatment of adults with MDD

RATIONALE

Vortioxetine has reduced depressive symptoms in adults with major depressive disorder (MDD) in multiple clinical trials.

OBJECTIVES

The aim of this study is to evaluate the efficacy, safety, and tolerability of vortioxetine 15 and 20 mg vs placebo in adults with MDD.

METHODS

Patients were randomized 1:1:1:1 to vortioxetine 15 mg, vortioxetine 20 mg, duloxetine 60 mg (active reference), or placebo. The primary efficacy endpoint was mean change in Montgomery-Åsberg Depression Rating Scale (MADRS) total score at week 8 (MMRM). Safety/tolerability assessments included physical examinations, vital signs, laboratory evaluations, electrocardiograms, adverse events (AEs), Columbia-Suicide Severity Rating Scale, Arizona Sexual Experiences Scale, and Discontinuation-Emergent Signs and Symptoms checklist.

RESULTS

Six hundred and fourteen patients were randomized. Mean changes in MADRS scores were -12.83 (±0.834), -14.30 (±0.890), -15.57 (±0.880), and -16.90 (±0.884) for placebo, vortioxetine 15 mg (P = .224), vortioxetine 20 mg (P = .023), and duloxetine 60 mg (P < .001) (P vs placebo), respectively. AEs reported by ≥5 % of vortioxetine patients included nausea, headache, diarrhea, dizziness, dry mouth, constipation, vomiting, insomnia, fatigue, and upper respiratory infection. Treatment-emergent sexual dysfunction, suicidal ideation or behavior, and discontinuation symptoms were not significantly different between vortioxetine and placebo.

CONCLUSIONS

Vortioxetine 20 mg significantly reduced MADRS total scores after 8 weeks of treatment. Both vortioxetine doses were well tolerated.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT01153009; www.clinicaltrials.gov/ .

The role of patient expectancy in placebo and nocebo effects in antidepressant trials

OBJECTIVE

To determine whether patient expectancy plays a role in observed placebo and nocebo effects in 2 clinical trials.

METHOD

Data were reanalyzed from 2 fluoxetine-discontinuation studies conducted from March 1990 to September 1992 and from May 1997 to December 2002. The 673 outpatients included were aged 18-65 years with DSM-III-R major depressive disorder (MDD), responded to 12-week duration open treatment, and were randomized to continued fluoxetine or placebo for an additional year. Participants in 1 of the included studies received a fixed dose of fluoxetine 20 mg daily, while the second study utilized flexible fluoxetine doses up to 60 mg daily. Mixed effects longitudinal models determined whether the possible randomization to placebo at 12 weeks resulted in significant depressive symptom worsening across treatments. Correlations were computed between early symptom change (weeks 1-3 of open treatment) and postrandomization symptom change (weeks 13-16 following randomization).

RESULTS

Participants continuing to receive fluoxetine and those switched to placebo had significantly higher mean Hamilton Depression Rating Scale (HDRS) scores immediately postrandomization compared to the final weeks of open treatment (P < .001 for both fluoxetine- and placebo-treated patients). In both studies, early HDRS change was significantly correlated with postrandomization HDRS change for patients receiving fluoxetine (r = -0.46, P < .001) as well as placebo (r = -0.48, P < .001).

CONCLUSIONS

The possibility of receiving placebo following 12 weeks of open fluoxetine was associated with significant symptom worsening in 2 large fluoxetine discontinuation studies. Worsening depression scores following randomization were significantly associated with the degree of improvement participants experienced during weeks 1-3 of open treatment. These results suggest that treatment changes influence patients' expectations of improvement, which, in turn, affect their depressive symptoms.

Pharmacology and clinical potential of vortioxetine in the treatment of major depressive disorder

VORTIOXETINE IS A NEW MULTIMODAL ACTION ANTIDEPRESSANT WITH TWO TYPES OF ACTION: serotonin transporter (SERT) blockade and a strong affinity for several serotoninergic receptors. It is an antagonist of the 5-HT3 and 5-HT7 receptors, a partial agonist of 5-HT1B, and an agonist of 5-HT1A. Its combined action on SERT and four subtypes of serotoninergic receptors increases the extracellular concentration of serotonin, dopamine, and noradrenaline. Twelve clinical trials have been carried out, nine of which had positive results versus placebo. When active comparators were included in the study design, no significant differences were found except in one study in which the efficacy of vortioxetine was superior to the comparator (agomelatine) in depression resistant to selective serotonin reuptake inhibitors (SSRI)/serotonin-norepinephrine reuptake inhibitors (SNRI) treatment. Tolerability studies indicate that the drug does not cause any important problems on blood tests, vital signs, or on electrocardiography. The lack of weight gain and induction of metabolic syndrome and the lack of significant changes in the QTc are especially important. The incidence rate of sexual dysfunction is low and similar to placebo in various trials. Similarly, cognitive function remains intact with vortioxetine.

Impact of patient selection and study characteristics on signal detection in placebo-controlled trials with antidepressants

An increasing rate of antidepressant trials fail due to large placebo responses. This analysis aimed to identify variables influencing signal detection in clinical trials of major depressive disorder. Patient-level data of randomized patients with a duloxetine dose ≥ 60 mg/day were obtained from Lilly. Total scores of the Hamilton Depression Rating scale (HAM-D) were used as efficacy endpoints. In total, 4661 patients from 14 studies were included in the analysis. The overall effect size (ES), based on the HAM-D total score at endpoint, between duloxetine and placebo was -0.272. Although no statistically significant interactions were found, the following results for factors influencing ES were seen: a very low ES (-0.157) in patients in the lowest baseline HAM-D category and in patients recruited in the last category of the recruitment period (-0.122). A higher ES in patients recruited in centers with a site-size at but not more than 2.5 times the average site-size for the study (-0.345). Study characteristics that resulted in low signal detection in our database were: <80% study completers, a HAM-D placebo response >5 points, a high variability of placebo response (SD > 7 points HAM-D), >6 post baseline visits per study, and use of an active control drug. Simpler trial designs, more homogeneous and mid-sized study sites, a primary analysis based on a higher cutoff blinded to investigators to avoid the influence of score inflation in mild patients and, if possible, studies without an active control group could lead to a better signal detection of antidepressive efficacy.

A model of placebo response in antidepressant clinical trials

Placebo response in clinical trials of antidepressant medications is substantial and has been increasing. High placebo response rates hamper efforts to detect signals of efficacy for new antidepressant medications, contributing to trial failures and delaying the delivery of new treatments to market. Media reports seize upon increasing placebo response and modest advantages for active drugs as reasons to question the value of antidepressant medication, which may further stigmatize treatments for depression and dissuade patients from accessing mental health care. Conversely, enhancing the factors responsible for placebo response may represent a strategy for improving available treatments for major depressive disorder. A conceptual framework describing the causes of placebo response is needed in order to develop strategies for minimizing placebo response in clinical trials, maximizing placebo response in clinical practice, and talking with depressed patients about the risks and benefits of antidepressant medications. In this review, the authors examine contributors to placebo response in antidepressant clinical trials and propose an explanatory model. Research aimed at reducing placebo response should focus on limiting patient expectancy and the intensity of therapeutic contact in antidepressant clinical trials, while the optimal strategy in clinical practice may be to combine active medication with a presentation and level of therapeutic contact designed to enhance treatment response.

Validation of computer-administered clinical rating scale: Hamilton Depression Rating Scale assessment with Interactive Voice Response technology--Japanese version

AIM

The aim of this study was to examine the reliability and validity of the Interactive Voice Response (IVR) program to rate the 17-item Hamilton Rating Scale for Depression (HAM-D) score in Japanese depressive patients.

METHODS

Depression severity was assessed in 60 patients by a clinician and psychologists using HAM-D. Scoring by the IVR program was conducted on the same and the following days. Test-retest reliability, internal consistency, and concurrent validity for total HAM-D scores were examined by calculating intraclass correlation coefficient, Cronbach's alpha, and Pearson's correlation coefficient. Inter-rater consistency for each HAM-D item was examined by Cohen's kappa.

RESULTS

Test-retest reliability of the IVR program was high (intraclass correlation coefficient: 0.93). Internal consistency of each total score obtained by the clinician, psychologists, and IVR program was high (Cronbach's alpha: 0.77, 0.79, 0.78, and 0.83). Regarding concurrent validity, correlation coefficients between total scores obtained by the clinician versus IVR and that by the clinician versus psychologists were high (0.81 and 0.93). The HAM-D total score rated by the clinician was 3 points lower than that of IVR. Inter-rater consistency for each HAM-D item evaluated by the clinician versus IVR was estimated to be fair (Cohen's kappa coefficient: 0.02-0.50).

CONCLUSION

Our results suggest that the Japanese IVR HAM-D program is reliable and valid to assess 17-item HAM-D total score in Japanese depressive patients. However, the current program tends to overestimate depression severity, and the score of each item did not always show high agreement with clinician's rating, which warrants further improvement in the program.

A randomized, double-blind, placebo-controlled 6-wk trial of the efficacy and tolerability of 5 mg vortioxetine in adults with major depressive disorder

Vortioxetine (Lu AA21004) is a multi-modal antidepressant in clinical development for the treatment of major depressive disorder (MDD). The current study evaluated the efficacy and tolerability of 5 mg vortioxetine compared to placebo after 6 wk of treatment in adults with MDD in an out-patient setting. Adults aged 18-75 yr, with a diagnosis of MDD and a baseline Montgomery-Asberg Depression Rating Scale (MADRS) total score ≥30, were randomized to receive either 5 mg vortioxetine or placebo over 6 wk, followed by a 2-wk medication-free discontinuation period. The primary efficacy measure was change from baseline in Hamilton Rating Scale for Depression (HAMD)-24 total score at week 6 compared to placebo. Additional measures included response and remission rates, Clinical Global Impression Scale - Improvement scores, HAMD-24 total score in subjects with baseline Hamilton Anxiety Scale (HAMA) >19 and MADRS-S total score. Adverse events (AEs) were assessed throughout the study. A total of 600 adults were randomized. There were no significant differences in efficacy measures between subjects in the 5 mg vortioxetine and placebo groups at week 6. HAMD-24 total score in subjects with baseline HAMA >19 in the 5 mg vortioxetine group was improved at weeks 3-6 compared to the placebo group (nominal p value <0.05). The most common AEs for the vortioxetine and placebo groups were nausea (19.1 and 9.4%), headache (17.1 and 15.1%) and diarrhoea (11.4 and 7.0%), respectively. In this study of adults with MDD, 5 mg vortioxetine did not differ significantly from placebo in reducing depression symptoms after 6 wk of treatment.

The efficacy and safety of bupropion sustained-release formulation for the treatment of major depressive disorder: a multi-center, randomized, double-blind, placebo-controlled study in Asian patients

This study was conducted to compare the efficacy and safety of bupropion sustained-release (SR) formulation orally administered at daily doses of 150 mg/day (once daily) and 300 mg/day (150 mg twice daily) for 8 weeks versus placebo in Asian patients with major depressive disorder. The mean change from baseline in Montgomery-Åsberg Depression Rating Scale (MADRS) total score at week 8 was compared between each of the bupropion SR dose groups and the placebo group using an analysis of covariance with the multiplicity adjustment by Dunnett's step-down procedure. A total of 569 subjects met all of the inclusion criteria and proceeded to the treatment phase. The subjects proceeding to the treatment phase included 454 Japanese patients and 115 Korean patients. There was no statistically significant difference between each of the bupropion SR dose groups and the placebo group in the primary efficacy endpoint of change from baseline in MADRS total score at week 8. Similar results were generally obtained for all of the secondary efficacy endpoints. The secondary analysis and the other subgroup analysis did not show a statistically significant difference in efficacy. There was no substantial difference in the type, severity, and incidence of adverse events (AEs) between the bupropion SR dose groups and the placebo group, which indicates a favorable safety profile for bupropion SR. There were no significant findings in subjects treated with bupropion SR in regard to sexual dysfunction, weight change, and withdrawal syndrome, which are frequently recognized as clinical concerns associated with selective serotonin reuptake inhibitors, widely used for the treatment of depression.

Vortioxetine (Lu AA21004) 5 mg in generalized anxiety disorder: results of an 8-week randomized, double-blind, placebo-controlled clinical trial in the United States

The goal of the current clinical study, conducted in the United States (US), was to evaluate the efficacy and tolerability of vortioxetine 5mg vs placebo in adults with a primary diagnosis of generalized anxiety disorder (GAD; HAM-A total score ≥20 and MADRS score ≤16). Subjects were randomized (1:1) to receive vortioxetine 5mg (n=152) or placebo (n=152) for 8 weeks. Efficacy was assessed using change from baseline in HAM-A total scores after 8 weeks of treatment compared with placebo, using mixed-model repeated measures (MMRM) analyses. Adverse events (AEs) were assessed throughout the study. A total of 304 subjects were randomized (mean age, 41.2 years). After 8 weeks of treatment, there was no statistically significant difference in the reduction in HAM-A total score from baseline between the Vortioxetine (n=145) and placebo (n=145) groups. There were no statistically significant differences in any key secondary efficacy outcome between vortioxetine and placebo. Factors potentially contributing to the differences between the results of this study and those of one of identical design conducted outside the US are discussed. The most common treatment-emergent AEs were nausea, headache, dizziness, and dry mouth. Nausea was more frequently reported in the vortioxetine group (25% vs 4.6% for the placebo group). Most AEs were mild to moderate in severity. In conclusion, in this trial, vortioxetine did not improve symptoms of GAD (compared with placebo) over 8 weeks of treatment. Vortioxetine was well tolerated in this study.

Vocal acoustic biomarkers of depression severity and treatment response

BACKGROUND

Valid, reliable biomarkers of depression severity and treatment response would provide new targets for clinical research. Noticeable differences in speech production between depressed and nondepressed patients have been suggested as a potential biomarker.

METHODS

One hundred five adults with major depression were recruited into a 4-week, randomized, double-blind, placebo-controlled research methodology study. An exploratory objective of the study was to evaluate the generalizability and repeatability of prior study results indicating vocal acoustic properties in speech may serve as biomarkers for depression severity and response to treatment. Speech samples, collected at baseline and study end point using an automated telephone system, were analyzed as a function of clinician-rated and patient-reported measures of depression severity and treatment response.

RESULTS

Regression models of speech pattern changes associated with clinical outcomes in a prior study were found to be reliable and significant predictors of outcome in the current study, despite differences in the methodological design and implementation of the two studies. Results of the current study replicate and support findings from the prior study. Clinical changes in depressive symptoms among patients responding to the treatments provided also reflected significant differences in speech production patterns. Depressed patients who did not improve clinically showed smaller vocal acoustic changes and/or changes that were directionally opposite to treatment responders.

CONCLUSIONS

This study supports the feasibility and validity of obtaining clinically important, biologically based vocal acoustic measures of depression severity and treatment response using an automated telephone system.

Placebo response in clinical trials with schizophrenia patients

PURPOSE OF REVIEW

The magnitude of placebo response is an important factor in the outcome of clinical trials, in that excessive placebo response can obscure true drug-placebo differences. There is ample evidence of the impact of elevated placebo response in trials of major depression, but less intensive research has been done in the area of schizophrenia. We present a current review of placebo response in clinical trials of schizophrenia.

RECENT FINDINGS

The existing evidence suggests that placebo response in schizophrenia trials may be similar in magnitude, quality, and impact to that observed in depression trials, and has similarly increased over the past several years. We discuss factors influencing excessive placebo response during the conduct of clinical trials and how they may be managed to help minimize placebo response.

SUMMARY

There does not appear to be any single major factor contributing to the high levels of placebo response in schizophrenia clinical trials; therefore, a multipronged approach to minimizing excessive placebo response or its impact is recommended.

Feasibility and validation of a computer-automated Columbia-Suicide Severity Rating Scale using interactive voice response technology

To evaluate a computer-automated version of the Columbia-Suicide Severity Rating Scale (C-SSRS) using interactive voice response technology (eC-SSRS™). The eC-SSRS assesses "Lifetime" ideations and behaviors at baseline and monitors suicidality prospectively thereafter. Ten control volunteers and ten psychiatric inpatients participated and were administered the C-SSRS at baseline and 4-8 days later by two experienced clinical trial raters. Study participants also completed the eC-SSRS using touch-tone telephones. Kappa measures of agreement compared inter-rater reliability of the C-SSRS administrations and the C-SSRS administrations with the eC-SSRS. Convergent validity with the Beck Scale for Suicide Ideation BSS and patient feedback forms were also evaluated. Twenty baseline and nineteen follow-up assessments were completed. In general, agreement between the eC-SSRS and each rater was comparable or superior to the agreement between both raters. Subject feedback and personal preferences varied across individuals, but were generally supportive of the feasibility and validity of the eC-SSRS. The reliability and validity of the C-SSRS and eC-SSRS for assessing suicidal ideation and behaviors were comparable in this first study comparing the methods. These data were obtained from relatively small patient samples recruited from a single investigational site over a relatively short follow-up period. They support the feasibility and validity of the eC-SSRS for prospective monitoring of suicidality for use in clinical trials or clinical care, but further research with larger samples, other patient populations, and longer follow-up periods is needed.

Why has the antidepressant-placebo difference in antidepressant clinical trials diminished over the past three decades?

The increasing rate of failure of antidepressant clinical trials has led to the assertion that antidepressants do not have meaningful clinical benefits. Our hypothesis was that the decrease in antidepressant-placebo differences in antidepressant clinical trials over the past three decades could be explained by changes in research design features rather than a lack of potency of the antidepressants being tested. We collected data from 130 double blind placebo controlled antidepressant clinical trials conducted between 1981 and 2008 that included 35,122 depressed patients with 23,157 patients assigned to antidepressants and 11,965 assigned to placebo. We conducted a hierarchical regression analysis of change in HAM-D scores in antidepressant and placebo groups separately with year of publication, and research design features as independent variables. We found that antidepressant-placebo differences in antidepressant clinical trials have declined markedly over the past three decades. Decline in change scores in the antidepressant group was related to mean total baseline HAM-D scores in the trial, the version of HAM-D used, and duration of trial. Similarly, decline in change scores in the placebo group was related to mean total baseline HAM-D scores, duration of trial, and year of publication. Overall, we found that antidepressant-placebo differences were statistically significantly higher in trials that used HAM-D 21 rather than HAM-D 17 and in trials that lasted 6 weeks or less. These data suggest that, apart from the efficacy of the antidepressant being tested, factors such as baseline HAM-D scores, version of HAM-D used and duration of trial have a significant impact on outcome. As such a clinician's assessment of the usefulness of antidepressants should not be based solely on the results of such clinical trials. In the meantime there is a need for continuing research to improve the methodology of antidepressant clinical trials. These data suggest that many aspects of the design of antidepressant trials have a significant impact on outcome. Further, these data suggest that the results of more recent placebo controlled trials do not adequately inform clinicians about the potential utility of antidepressants.

Development of a patient-reported assessment to identify placebo responders in a generalized anxiety disorder trial

Placebo response is thought to be a primary contributor to uninformative (failed) trials in clinical drug development. This study describes the development of a patient-reported assessment to detect likely placebo responders. A novel scale, the Placebo Response Screening Scale (PRSS), was developed to assess domains expected to be associated with placebo response. The scale was administered during the screening visit of a 4-week, placebo-controlled study of alprazolam and an investigational compound in 211 patients with generalized anxiety disorder (GAD). Items that predicted placebo response were identified. Sensitivity and specificity of the instrument were used to determine a threshold score for use in screening likely placebo response. The PRSS was then evaluated by comparing active treatment and placebo groups and subsetting the groups based on subject PRSS scores. Twenty items were selected for being predictive of patient global improvement rating, clinician global improvement rating, or improvement on Hamilton Rating Scale for Anxiety (HAM-A) scores in placebo-arm patients. Receiver operating characteristic concordance values ranged from 0.77 to 0.96 for the different definitions of placebo responder. A cut-score of 50 on a scale of 0-100 was chosen to maximize sensitivity (range 0.67-0.79) and specificity (range 0.78-1.00). Fifty-six patients with scores of 50 or higher were flagged as potential placebo responders. Excluding these 56 patients from the analysis resulted in a greater separation of active treatment from placebo. The PRSS is a promising tool for predicting placebo response in clinical trials and requires further use and validation.