Eric Jacob Watsky

A Randomized Evaluation of the Effects of Six Antipsychotic Agents on Qtc, In the Absence and Presence of Metabolic Inhibition

Many drugs have been associated with QTc prolongation and, in some cases, this is augmented by concomitant administration with metabolic inhibitors. The effects of 6 antipsychotics on the QTc interval at and around the time of estimated peak plasma/serum concentrations in the absence and presence of metabolic inhibition were characterized in a prospective, randomized study in which patients with psychotic disorders reached steady-state on either haloperidol 15 mg/d (n = 27), thioridazine 300 mg/d (n = 30), ziprasidone 160 mg/d (n = 31), quetiapine 750 mg/d (n = 27), olanzapine 20 mg/d (n = 24), or risperidone 6-8 mg/d increased to 16 mg/d (n = 25/20). Electrocardiograms (ECGs) were done at estimated Cmax at steady-state on both antipsychotic monotherapy and after concomitant administration of appropriate cytochrome P-450 (CYP450) inhibitor(s). Mean QTc intervals did not exceed 500 milliseconds in any patient taking any of the antipsychotics studied, in the absence or presence of metabolic inhibition. The mean QTc interval change was greatest in the thioridazine group, both in the presence and absence of metabolic inhibition. The presence of metabolic inhibition did not significantly augment QTc prolongation associated with any agent. Each of the antipsychotics studied was associated with measurable QTc prolongation at steady-state peak plasma concentrations, which was not augmented by metabolic inhibition. The theoretical risk of cardiotoxicity associated with QTc prolongation should be balanced against the substantial clinical benefits associated with atypical antipsychotics and the likelihood of other toxicities.

Meta-Regression Analysis of Placebo Response in Antipsychotic Trials, 1970-2010

OBJECTIVE Large placebo response presents a major challenge for psychopharmacologic drug development and contributes to the increasing failure of psychiatric trials. The objective of this meta-regression analysis was to identify potential contributors to placebo response in randomized controlled trials of antipsychotic treatment in schizophrenia. METHOD The authors extracted trial design and clinical variables from eligible randomized controlled trials (N=50) identified through searches of MEDLINE (1960-2010) and other sources. Standardized mean change (SMC) was used as the effect size measure for placebo response, based on change scores on the Brief Psychiatric Rating Scale or the Positive and Negative Syndrome Scale from baseline to endpoint (2 to 12 weeks). RESULTS The results suggest significant heterogeneities (Q=387.83, df=49) in the magnitude of placebo response (mean SMC, -0.33, range -1.4 to 0.9) and in study quality. Both placebo SMC and study quality increased over time. Younger age, shorter duration of illness, greater baseline symptom severity, and shorter trial duration were significantly associated with greater placebo response, while country (United States compared with other countries) was not. More study sites, fewer university or Veterans Affairs treatment settings, and a lower percentage of patients assigned to receive placebo were associated with a greater placebo response, but these were not independent of publication year. Study quality affected the variability but not mean levels of placebo response. CONCLUSIONS This study identified important patient characteristics and trial design factors affecting the level of placebo response and hence the likelihood of detecting efficacy signals in randomized controlled trials. Future studies should test whether controlling these factors improves the detection of an antipsychotic effect.

Remission in schizophrenia: 196-week, double-blind treatment with ziprasidone vs . haloperidol

To compare the remission rate and its time-course over 196 wk of double-blind treatment with an atypical antipsychotic, ziprasidone (80-160 mg/d given b.i.d., or 80-120 mg/d given q.d.), or a conventional antipsychotic, haloperidol (5-20 mg/d). Outcome assessments included attainment of remission (Andreasen criteria) by longitudinal analysis. Positive and Negative Syndrome Scale (PANSS) scores, Global Assessment of Functioning Scale (GAF) scores, and quality-of-life (QLS) were also assessed in the initial 40-wk study phase (n=599) and the 3-yr extension study (n=186). Discontinuation rates in the initial 40-wk core and follow-up extension studies were comparable between groups: 64% and 65% for the 80-160 mg/d ziprasidone group, 65% and 58% for the 80-120 mg/d ziprasidone group, and 60% and 66% for the 5-20 mg/d haloperidol group, respectively. Mean change scores from baseline to LOCF endpoint (week 40 or early termination) for PANSS negative and GAF (primary efficacy variables) were not statistically significantly different between ziprasidone and haloperidol. During the 3-yr extension study, ziprasidone-treated subjects (80-160 mg/d) were more likely to achieve remission (51%) than haloperidol-treated (40%) subjects (p=0.04), while there was a favourable trend associated with 80-120 mg/d ziprasidone (48%). Compared to the haloperidol group, subjects assigned to the 80-160 mg/d ziprasidone group showed a gradual and persistent improvement in remission (p=0.006) and quality-of-life (p=0.004) in the longitudinal analyses. Significant differences in the trajectory of PANSS total and GAF scores favouring the 80-160 mg/d ziprasidone group were also observed. In this long-term, double-blind study, ziprasidone treatment was more likely to result in remission than haloperidol treatment, and was associated with greater improvement in quality-of-life.

A post hoc analysis of negative symptoms and psychosocial function in patients with schizophrenia: a 40-week randomized, double-blind study of ziprasidone versus haloperidol followed by a 3-year double-blind extension trial.

Schizophrenia is a persistent, lifelong illness such that enduring functional improvements may only occur over the course of years. This post hoc analysis in stable outpatients with schizophrenia investigated the negative symptom efficacy and treatment outcomes of ziprasidone (80-160 mg/d given twice a day, mean modal dose of 112 mg/d; and 80-120 mg/d given every day, mean modal dose of 96 mg/d) versus haloperidol (5-20 mg/d, mean modal dose of 12 mg/d) in a randomized, 40-week, double-blind study, followed by a double-blind continuation trial that extended up to 156 additional weeks. Symptomatic and functional recovery criteria were met when subjects attained both negative symptom remission and adequate psychosocial functioning based on the 4 Quality-of-Life subscales (instrumental role, interpersonal relations, participation in community, and intrapsychic foundations). Negative symptom remission (P = 0.005), as well as sustained adequate functioning (6 months) in instrumental role (P = 0.04) and participation in community (P = 0.02), was associated with significantly shorter time to remission in the ziprasidone 80 to 160 mg group than in the haloperidol group, as was the combination of symptomatic and functional recovery during the 196-week double-blind study period. A similar pattern was observed for the ziprasidone 80 to 120 mg group, which showed significant differences versus haloperidol in negative symptom remission and instrumental role functioning (but not other Quality-of-Life subscale measures). The clinically relevant outcome differences detected in this post hoc exploratory analysis support the potential for both enhanced remission in negative symptoms and psychosocial recovery during long-term treatment with an atypical agent and add to our understanding regarding the degree to which negative symptom remission can be attained in the maintenance phase.

Placebo response trajectories in short-term and long-term antipsychotic trials in schizophrenia

Increasing rates of placebo response have eroded placebo-control group differences in randomized controlled trials, although the reasons for this trend remain unclear. Data were extracted from the placebo arms in two identically designed 6-week studies and one 52-week study in the ziprasidone clinical trial database. The objective of this analysis was to identify distinct patterns of placebo response trajectories that could capture individual variability in the time course of change during a 1-year trial using growth mixture latent class analyses. These long-term placebo response patterns were contrasted with two 6-week schizophrenia studies. The placebo response trajectory analysis that showed 58% (Group 4) had gradual improvement in the PANSS negative subscale score (p<0.05), fewer dropouts (p<0.05) and improvement in abnormal movements, contrasted with 3 other trajectory groups that showed worsening on these measures. Almost all subjects (98%) in this symptom improvement group were treated with conventional antipsychotics just prior to placebo treatment. In contrast, the trajectory analyses showed worsening of symptoms based on PANSS total score in the 1-year trial (+15.5, SEM 2.6). Some gradual improvement of symptoms (-14.0, SEM 1.6) was also noted in 67% (n=114) of patients in the 6-week short term trials. Our findings indicate that substantial heterogeneity in placebo response occurs in both short-term and long-term trials. The placebo response trajectories appeared to depend on the efficacy measure of symptom reduction chosen, prior antipsychotic use profile, and trial durations. Further research is warranted to examine the trajectory patterns of placebo responses in independent patient populations.

Results from the single-use autoinjector for self-administration of subcutaneous interferon beta-1a in patients with relapsing multiple sclerosis (MOSAIC) study

Background: Patients with multiple sclerosis (MS) often receive long-term injectable therapy, and difficulties associated with self-injection can affect treatment adherence and efficacy. Objective: The objective of this study was to evaluate an investigational, ready-to-use, single-use autoinjector for self-injection of subcutaneous (sc) interferon beta-1a (IFNβ-1a). Methods: In this multicenter, open-label, single-arm study, patients with relapsing MS who were receiving IFNβ-1a sc 44 μg three times weekly for ≥ 12 weeks continued therapy using a single-use autoinjector and completed a user trial questionnaire at baseline and weeks 6 and 12. The primary endpoint was the proportion of patients rating the autoinjector as easy or very easy to use at week 12. Results: At 12 weeks, 86% of 109 patients included in the intent-to-treat population rated the autoinjector easy or very easy to use (95% confidence interval, 80% − 93%), and the most important perceived benefit was its overall convenience. The majority (74%) of patients reported the device as somewhat or extremely convenient to use, and most (83%) agreed or strongly agreed that the device made injections simple. Conclusion: The single-use autoinjector was well received and supported by favorable ratings for simplified injections and convenience. The results suggest that the device may improve overall injection experience in patients with relapsing MS.

The effect of tafamidis on the QTc interval in healthy subjects

AIMS The transthyretin (TTR) stabilizer, tafamidis, has demonstrated efficacy and safety in the treatment of TTR familial amyloid polyneuropathy (20 mg day(-1) ). Tafamidis use in TTR cardiomyopathy led to the study of the potential effect of tafamidis on the QTc interval in healthy subjects. METHODS This randomized, three treatment, three period, six sequence crossover study with placebo, a positive control (moxifloxacin 400 mg) and tafamidis (400 mg, to achieve a supra-therapeutic Cmax of ~20 µg ml(-1) ) was conducted in healthy volunteers at three clinical research units. Oral dosing in each of the three treatment periods was separated by a washout period of  ≥ 14 days. Serial triplicate 12-lead electrocardiograms were performed. QTc intervals were derived using the Fridericia correction method. Safety and tolerability were assessed by physical examination, vital signs measurement, laboratory analyses and monitoring of adverse events (AEs). RESULTS A total of 42 subjects completed the study. The upper limit of the two-sided 90% confidence intervals (CIs) for the difference in baseline-adjusted QTc F between tafamidis 400 mg and placebo was <10 ms (non-inferiority criterion) for all time points. The lower limit of the two-sided 90% CI between moxifloxacin 400 mg and placebo exceeded 5 ms at the pre-specified moxifloxacin tmax of 3 h post-dose, confirming assay sensitivity. Cmax and AUC(0,24 h) for tafamidis were 20.36 µg ml(-1) and 305.4 µg ml(-1) h, respectively. There were no serious/severe AEs or treatment discontinuations due to AEs. CONCLUSIONS This thorough QTc study suggests that a supra-therapeutic single 400 mg oral dose of tafamidis does not prolong the QTc interval and is well-tolerated in healthy volunteers.

PLACEBO RESPONSE IN ANTIPSYCHOTIC TRIALS: A SYSTEMATIC REVIEW AND META-ANALYSIS

we determined that TrkB is capable of direct physical interaction with ERa; suggesting that the two proteins may partner in the control of gene expression. However, TrkB was found to localize in the cell membrane and cytoplasm but not in the nucleus. Discussion: Our results suggest that the potentiating effect of TrkB on ERa-mediated transcription was not via co-entry into the nucleus, but instead involves phosphorylation of the ERa protein which likely occurs in the cytoplasm. However, the inability of estrogen to induce TrkB phosphorylation suggests that this stimulatory effect of TrkB-ERa is not bi-directional. Considering that both ERa and TrkB have been found to be altered in the brains of patients with schizophrenia, our finding that TrkB is able to increase ERa activity suggests that dysfunction in TrkB signalling may occur upstream of a dysfunction in ERa in some people with schizophrenia. Our finding of a molecular convergence between these two schizophrenia susceptibility pathways provides a novel perspective for the development of pharmacological agents to target these deficient pathways.