Development of a straightforward and sensitive scale for MCI and early AD clinical trials.

BACKGROUND: Although the Clinical Dementia Rating Scale-Sum of Boxes score (CDR-SB) is a widely accepted and commonly used global scale, validated clinical endpoints of cognitive changes are unavailable in the predementia stages of Alzheimer's disease (AD), and a new clinical assessment with reliability and sensitivity is needed in the mild cognitive impairment (MCI) population. METHODS: Using Alzheimer's Disease Neuroimaging Initiative (ADNI)-1/GO data, signal-to-noise ratios (SNRs) were calculated to quantify the sensitivity of a measure for detecting disease progression and hypothetical treatment effects. All possible combinations of selected sensitive measures were assessed for developing composite scores. The analyses were performed in the MCI population and subpopulations enriched by apolipoprotein E4 (APOE ε4), hippocampal volume, and cerebrospinal fluid ß-amyloid. RESULTS: The best composite score was "Word Recall + Delayed Word Recall + Orientation + CDR-SB + FAQ", more sensitive than 13-item Alzheimer's Disease Assessment Scale-cognitive subscale or CDR-SB. CONCLUSION: The proposed composite score derived from the existing clinical endpoints demonstrated higher sensitivity in the MCI population and is easy to implement and standardize across studies.

Perspectives on clinical trial data transparency and disclosure.

The increased demand for transparency and disclosure of data from clinical trials sponsored by pharmaceutical companies poses considerable challenges and opportunities from a statistical perspective. A central issue is the need to protect patient privacy and adhere to Good Clinical and Statistical Practices, while ensuring access to patient-level data from clinical trials to the wider research community. This paper offers options to navigate this dilemma and balance competing priorities, with emphasis on the role of good clinical and statistical practices as proven safeguards for scientific integrity, the importance of adopting best practices for reporting of data from secondary analyses, and the need for optimal collaboration among stakeholders to facilitate data sharing.

Understanding placebo responses in Alzheimer's disease clinical trials from the literature meta-data and CAMD database.

BACKGROUND: The placebo response and the underlying disease progression is difficult to differentiate in longitudinal Alzheimer's disease (AD) studies, yet it is crucial to understand for designing clinical trials and interpreting results. OBJECTIVES: The placebo response in ADAS-cog11 from various studies was evaluated against model predictions derived from historical placebo data to demonstrate potential interpretation of study results using a prior understanding of expected disease progression. METHODS: The placebo response component from a previously published disease progression model was used to estimate the longitudinal placebo response, and the disease progression in the placebo group in various case studies were evaluated. In addition, placebo data from the Coalition Against Major Diseases (CAMD) database in mild to moderate AD patients is described. RESULTS: The case studies demonstrated potential different results in disease progression in a placebo group, and the impact on understanding the magnitude of drug effect. Baseline cognitive function is an important covariate of disease progression, therefore, it is important to evaluate the baseline severity and predict disease progression accordingly when comparing trial results. Furthermore, study duration, sample size, and study design may affect the placebo response, all of which have the potential to confound understanding of study results. CONCLUSION: The recent failures in Phase III AD studies are not likely due to insufficient cognitive decline in the control groups. A meta-analytic approach using all available data provides a robust understanding of placebo effect, disease progression, and potential interpretation of treatment effects, and offers a useful tool to aid in both trial design and interpretation.

Disease progression model for cognitive deterioration from Alzheimer's Disease Neuroimaging Initiative database.

BACKGROUND: A mathematical model was developed to describe the longitudinal response in Alzheimer's Disease Assessment Scale-cognitive (ADAS-cog) obtained from the Alzheimer's Disease Neuroimaging Initiative. METHODS: The model was fit to the longitudinal ADAS-cog scores from 817 patients. Risk factors (age, apolipoprotein ɛ4 [APOE ɛ4] genotype, gender, family history of AD, years of education) and baseline severity were tested as covariates. RESULTS: Rate of disease progression increased with baseline severity. Age, APOE ɛ4 genotype, and gender were identified as potential covariates influencing disease progression. The rate of disease progression in patients with mild to moderate AD was estimated as approximately 5.5 points/yr. CONCLUSIONS: A disease progression model adequately described the natural decline of ADAS-cog observed in Alzheimer's Disease Neuroimaging Initiative. Baseline severity is an important covariate to predict a curvilinear rate of disease progression in normal elderly, mild cognitive impairment, and AD patients. Age, APOE ɛ4 genotype, and gender also influence the rate of disease progression.

Effects of high-dose ziprasidone and haloperidol on the QTc interval after intramuscular administration: a randomized, single-blind, parallel-group study in patients with schizophrenia or schizoaffective disorder.

BACKGROUND: Antipsychotic agents have been associated with a prolonged QT interval. Data on the effects of ziprasidone and haloperidol on the QTc interval are lacking. OBJECTIVE: This study aimed to characterize the effects of 2 high-dose intramuscular injections of ziprasidone and haloperidol on the QTc interval at T(max). METHODS: This randomized, single-blind study enrolled patients with schizophrenia or schizoaffective disorder in whom long-term antipsychotic therapy was indicated. Patients were randomized to receive 2 high-dose intramuscular injections of ziprasidone (20 and 30 mg) or haloperidol (7.5 and 10 mg) separated by 4 hours. The primary outcome measure was the mean change from baseline in QTc at the T(max) of each injection. Each dose administration was followed by serial ECG and blood sampling for pharmacokinetic determinations. Twelve-lead ECG data were obtained immediately before and at predetermined times after injections. ECG tracings were read by a blinded central reader. Blood samples were obtained immediately before and after injections. Point estimates and 95% CIs for mean QTc and changes from baseline in QTc were estimated. No between-group hypothesis tests were conducted. For the assessments of tolerability and safety profile, patients underwent physical examination, including measurement of vital signs, clinical laboratory evaluation, and monitoring for adverse events (AEs) using spontaneous reporting. RESULTS: A total of 59 patients were assigned to treatment, and 58 received study medication (ziprasidone, 31 patients; haloperidol, 27; age range, 21-72 years; 79% male). After the first injection, mean (95% CI) changes from baseline were 4.6 msec (0.4-8.9) with ziprasidone (n = 25) and 6.0 msec (1.4-10.5) with haloperidol (n = 24). After the second injection, these values were 12.8 msec (6.7-18.8) and 14.7 msec (10.2-19.2), respectively. Mild and transient changes in heart rate and blood pressure were observed with both treatments. None of the patients had a QTc interval >480 msec. Two patients in the ziprasidone group experienced QTc prolongation >450 msec (457 and 454 msec) and QTc changes that exceeded 60 msec (62 and 76 msec) relative to the time-matched baseline values. With haloperidol, QTc interval values were <450 msec with no changes >60 msec. Treatment-emergent AEs were reported in 29 of 31 patients (93.5%) in the ziprasidone group and 25 of 27 patients (92.6%) in the haloperidol group; most events were of mild or moderate severity. Frequently reported AEs were somnolence (90.3% and 81.5%, respectively), dizziness (22.6% and 7.4%), anxiety (16.1% and 7.4%), extrapyramidal symptoms (6.5% and 33.3%), agitation (6.5% and 18.5%), and insomnia (0% and 14.8%). CONCLUSIONS: In this study of the effects of high-dose ziprasidone and haloperidol in patients with schizophrenic disorder, none of the patients had a QTc interval >480 msec, and changes from baseline QTc interval were clinically modest with both drugs. Both drugs were generally well tolerated.

Effects of Oral Ziprasidone and Oral Haloperidol on QTc interval in patients with Schizophrenia or Schizoaffective disorder.

STUDY OBJECTIVE: To characterize the effect of oral ziprasidone and haloperidol on the corrected QT (QTc) interval under steady-state conditions. Design. Prospective, randomized, open-label, parallel-group study. SETTING: Inpatient clinical research facility. Patients Fifty-nine adults (age range 25-59 yrs) with schizophrenia or schizoaffective disorder who had no clinically significant abnormality on electrocardiogram (ECG) at screening. Intervention. During period 1 (days -10 to -4), antipsychotic and anticholinergic drugs were tapered. On the first day (day -3) of period 2, the drugs were discontinued, and placebo was given for the next 3 days (days -2 to 0). On the last day (day 0) of period 2, serial baseline ECGs were collected. During period 3 (days 1-16), patients received escalating oral doses of ziprasidone and haloperidol to reach steady state. Period 4 (days 17-19) allowed for study drug washout and initiation of outpatient antipsychotic therapy; safety assessments were also performed during this period. MEASUREMENTS AND RESULTS: At each steady-state dose level, three ECGs and a serum or plasma sample were collected at the predicted time of peak exposure to the administered drug. Point estimates and 95% confidence intervals (CIs) were determined for the mean QTc interval at baseline and for the mean change from baseline in QTc at each steady-state dose level. Mean changes from baseline in the QTc interval (msec) for ziprasidone were 4.5 (95% CI 1.9-7.1), 19.5 (95% CI 15.5-23.4), and 22.5 (95% CI 15.7- 29.4) for steady-state doses of 40, 160, and 320 mg/day, respectively; for haloperidol, -1.2 (95% CI -4.1-1.7), 6.6 (95% CI 1.6-11.7), and 7.2 (95% CI 1.4-13.1) for steady-state doses of 2.5, 15, and 30 mg/day. Although no patient in either treatment group experienced a QTc interval of 450 msec or greater, the QTc interval increased 30 msec or more in 11 and 17 ziprasidone-treated patients at 160 and 320 mg/day, respectively, and in 3 and 5 haloperidol-treated patients at 15 and 30 mg/day, respectively. Most treatment-emergent adverse drug reactions were mild in intensity, and none were severe. CONCLUSION: The QTc interval in ziprasidone- and haloperidol-treated patients increased with dose. Treatment with high doses of ziprasidone or haloperidol did not result in any patient experiencing a QTc interval of 450 msec or greater.

Efficacy and safety of the novel selective nicotinic acetylcholine receptor partial agonist, varenicline, for smoking cessation.

BACKGROUND: The selective nicotinic acetylcholine receptor partial agonist, varenicline tartrate, represents a novel type of therapy for smoking cessation. This study evaluated the efficacy, safety, and tolerability of 4 varenicline dose regimens, 2 with progressive dosing over the first week (eg, titrated) and 2 with a fixed dosing schedule (eg, non-titrated), for promoting smoking cessation. METHODS: This multicenter, double-blind, placebo-controlled study randomized healthy smokers (aged 18-65 years) to varenicline tartrate, 0.5 mg twice daily nontitrated (n = 129), 0.5 mg twice daily titrated (n = 130), 1.0 mg twice daily nontitrated (n = 129), 1.0 mg twice daily titrated (n = 130), or placebo (n = 129) for 12 weeks to aid in smoking cessation. A 40-week follow-up period assessed long-term efficacy. The primary efficacy measures were the carbon monoxide-confirmed 4-week continuous quit rates by pooled dosage group for weeks 4 through 7 and 9 through 12 and the continuous abstinence rates for weeks 9 through 52. RESULTS: Weeks 9 through 12 continuous quit rates were greater in the 1.0-mg group (49.4%) and the 0.5-mg group (44.0%) vs placebo (11.6%; P<.001 vs both doses). Weeks 9 through 52 abstinence rates were greater in the 1.0-mg group (22.4%; P<.001) and the 0.5-mg group (18.5%; P<.001) vs placebo (3.9%). Varenicline was generally well tolerated, with nausea occurring in 16% to 42% of varenicline-treated subjects. Reports of nausea were lower for the titrated vs nontitrated dosing and infrequently led to medication discontinuation. CONCLUSION: Varenicline tartrate, 0.5 mg and 1.0 mg twice daily, is efficacious for smoking cessation.

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.

The anxiolytic effect of the novel antipsychotic ziprasidone compared with diazepam in subjects anxious before dental surgery.

The novel atypical antipsychotic ziprasidone has a pharmacologic profile notable for potent agonism of serotonin (5-HT)1A receptors, antagonism at 5-HT1D receptors, and reuptake inhibition of norepinephrine. 5-HT1A receptor agonism, in particular, suggests anxiolytic activity, and ziprasidone has shown preliminary efficacy in treating the symptoms of anxiety associated with psychotic disorders. In this study, the anxiolytic efficacy of ziprasidone was evaluated in nonpsychotic subjects who were anxious before undergoing minor dental surgery. We compared a single oral dose of 20 mg ziprasidone (N = 30) with that of 10 mg diazepam (N = 30) and placebo (N = 30) in a randomized, parallel-group, double-blind study. The peak anxiolytic effect of ziprasidone compared with that of placebo was similar to that of diazepam but had a later onset. At 3 hours postdose, the anxiolytic effect of ziprasidone was significantly greater than that of placebo (p < 0.05) and somewhat greater than that of diazepam. Diazepam showed a significantly greater anxiolytic effect than placebo at 1 hour (p < 0.05) but not at 3 hours. The sedative effect of ziprasidone was never greater than that of placebo, whereas that of diazepam was significantly greater than that of placebo 1 to 1.5 hours postdose. Ziprasidone was generally well tolerated. Only one patient reported treatment-related adverse events (nausea and vomiting) and, unlike diazepam, ziprasidone did not cause reductions in blood pressure. Dystonia, extrapyramidal syndrome, akathisia, and postural hypotension were not seen with ziprasidone. Thus, ziprasidone may possess anxiolytic effects in addition to its antipsychotic properties.