Clinical Trial Setting (clinical + trial_setting)

Distribution by Scientific Domains


Selected Abstracts


Times to pain relief and pain freedom with rizatriptan 10 mg and other oral triptans

INTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 7 2007
D. S. Ng-Mak
Summary Background:, In the clinical trial setting, oral rizatriptan 10 mg has greater efficacy than other oral triptans in freedom from migraine headache pain 2 h after dosing. Objective:, The study objective is to compare the effectiveness of rizatriptan 10 mg and other oral triptans for acute migraine attack in a naturalistic setting. Methods:, A total of 673 patients took rizatriptan 10 mg or their usual-care oral triptans for two migraine attacks in a sequential, cross-over manner and recorded outcomes using a diary and a stopwatch. Mean and median times to pain relief (PR) and pain freedom (PF) for rizatriptan and other oral triptans were compared. The effect of rizatriptan on times to PR and PF, adjusting for potential confounding factors (treatment sequence, treatment order and use of rescue medication), was computed via a Cox proportional hazard model. Results:, Significantly, more patients taking rizatriptan achieved both PR and PF within 2 h after dosing than other oral triptans. Times to PR and PF were shorter with rizatriptan than with other oral triptans (median time to PR: 45 vs. 52 min, p < 0.0001; median time to PF: 100 vs. 124 min, p < 0.0001). The adjusted proportional hazard ratios (rizatriptan vs. other oral triptans) for times to PR and PF were 1.32 (95% CI: 1.22,1.44) and 1.27 (95% CI: 1.16,1.39) respectively. Conclusion:, The times to PR and PF in a ,naturalistic' setting were significantly shorter for patients treating a migraine attack with rizatriptan 10 mg than with other oral triptans. [source]


A multi-center 1H MRS study of the AIDS dementia complex: Validation and preliminary analysis

JOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 6 2003
Patricia Lani Lee PhD
Abstract Purpose To demonstrate the technical feasibility and reliability of a multi-center study characterizing regional levels of the brain metabolite ratios choline (Cho)/creatine (Cr) and myoinositol (MI)/Cr, markers of glial cell activity, and N-acetyl aspartate (NAA)/Cr, a marker of mature neurons, in subjects with AIDS dementia complex (ADC). Materials and Methods Using an automated protocol (GE PROBE-P), short echo time spectra (TE = 35 msec) were obtained at eight sites from uniformly prepared phantoms and from three brain regions (frontal white matter, basal ganglia, and parietal cortex) of normal volunteers and ADC and HIV-negative subjects. Results A random-effects model of the phantom and volunteer data showed no significant inter-site differences. Feasibility of a multi-center study was further validated by detection of significant differences between the metabolite ratios of ADC subjects and HIV-negative controls. ADC subjects exhibited significantly higher Cho/Cr and MI/Cr in the basal ganglia and significantly reduced NAA/Cr and significantly higher MI/Cr in the frontal white matter. These results are consistent with the predominantly subcortical distribution of the pathologic abnormalities associated with ADC. Conclusion This is the first study to ascertain and validate the reliability and reproducibility of a short echo time 1H-MRS acquisition sequence from multiple brain regions in a multi-center setting. It should now be possible to examine the regional effects of HIV infection in the brain in a large number of subjects and to study the metabolic effects of new therapies for the treatment of ADC in a clinical trial setting. J. Magn. Reson. Imaging 2003;17:625,633. © 2003 Wiley-Liss, Inc. [source]


Long-interval T2-weighted subtraction magnetic resonance imaging: A powerful new outcome measure in multiple sclerosis trials

ANNALS OF NEUROLOGY, Issue 5 2010
Bastiaan Moraal MD
Objective To compare long-interval T2-weighted subtraction (T2w-Sub) imaging with monthly gadolinium-enhanced T1-weighted (Gd-T1w) imaging for (1) detection of active lesions, (2) assessment of treatment efficacy, and (3) statistical power, in a multiple sclerosis (MS), phase 2, clinical trial setting. Methods Magnetic resonance imaging (MRI) data over 9 months from 120 patients (61 treatment, 59 placebo) from the oral temsirolimus trial were used. T2w-Sub images were scored for active lesions, independent of the original reading of the monthly Gd-T1w images. Treatment efficacy was evaluated using the nonparametric Mann-Whitney U test, and parametric negative binomial (NB)-regression and power calculations were conducted. Results Datasets from 116 patients (58 treatment, 58 placebo) were evaluated. The mean number of T2w-Sub lesions in the treatment group was 3.0 (±4.6) versus 5.9 (±8.8) for placebo; the mean cumulative number of new Gd-T1w lesions in the treatment group was 5.5(±9.1) versus 9.1(±17.2) for placebo. T2w-Sub imaging showed increased power to assess treatment efficacy compared with Gd-T1w imaging, when evaluated by Mann-Whitney U test (p = 0.017 vs p = 0.177), or NB-regression without (p = 0.011 vs p = 0.092) or with baseline adjustment (p < 0.001 vs p = 0.002). Depending on the magnitude of the simulated treatment effect, sample size calculations showed reductions of 22 to 34% in the number of patients (translating into reductions of 81,83% in the number of MRI scans) needed to detect a significant treatment effect in favor of T2w-Sub imaging. Interpretation Compared with monthly Gd-T1w imaging, long-interval T2w-Sub MRI exhibited increased power to assess treatment efficacy, and could greatly increase the cost-effectiveness of phase 2 MS trials by limiting the number of patients, contrast injections, and MRI scans needed. ANN NEUROL 2010;67:667,675 [source]


Antiretroviral effects on HIV-1 RNA, CD4 cell count and progression to AIDS or death: a meta-regression analysis

HIV MEDICINE, Issue 10 2008
EJ Mills
Objective Governments, clinicians and drug-licensing bodies have adopted changes in CD4 cell counts and HIV-1 RNA levels as evidence of effectiveness for new therapeutic interventions. We aimed to determine the strength of the association between the magnitude of the effect of changes in CD4 cell count and HIV-1 RNA and progression to AIDS or death in the highly active antiretroviral therapy (HAART) era. Methods We identified all randomized clinical trials (RCTs) evaluating the effect of HAART on both clinical and surrogate endpoints (1994 to September 2006). We performed a meta-regression and weighted linear regression. We additionally estimated potential RCT sample sizes that would be required to assess the effectiveness of new interventions in terms of clinical endpoints. Results We included data from 178 RCTs. We were unable to demonstrate a strong relationship at any time-point. Specifically, this was the case when CD4 T-cell change and clinical outcomes were examined at week 24 [coefficient ,0.01, 95% confidence interval (CI) ,0.03 to 0.001, P=0.54], week 48 (coefficient ,0.01, 95% CI ,0.02 to 0.001, P=0.83) and week 96 (coefficient 0.00, 95% CI ,0.03 to 0.04, P=0.76). This was also the case when viral load was examined as a surrogate marker. Given the small number of clinical events occurring in new interventional RCTs, any RCT aiming to evaluate clinical endpoints within these time-points would require an exceptionally large sample size. Conclusions Our findings indicate that, within short-term clinical trial settings, it is not possible to estimate the proportion of treatment effect associated with surrogate endpoints. [source]


Penile rehabilitation protocol after robot-assisted radical prostatectomy: assessment of compliance with phosphodiesterase type 5 inhibitor therapy and effect on early potency

BJU INTERNATIONAL, Issue 3 2010
Daniel J. Lee
Study Type , Therapy (case series) Level of Evidence 4 OBJECTIVE To evaluate factors that affect compliance in men who enrol in a phosphodiesterase type 5 inhibitor (PDE5I) protocol after nerve-sparing robot-assisted prostatectomy (RAP), and report on short-term outcomes, as PDE5Is may help restore erectile function after RAP and patient adherence to the regimen is a factor that potentially can affect outcome. PATIENT AND METHODS We prospectively followed 77 men who had nerve-sparing RAP and enrolled in a postoperative penile rehabilitation protocol. The men received either sildenafil citrate or tadalafil three times weekly. The minimum follow-up was 8 weeks. Potency was defined as erection adequate for penetration and complete intercourse. Compliance was defined as men adhering to the regimen for ,2 months. RESULTS The mean age of the cohort was 57.8 years and the median follow-up was 8 months. In all, 32% of the men discontinued the therapy <2 months after RAP and were deemed noncompliant with an additional 39% discontinuing therapy by 6 months, with the high cost of medication being the primary reason (65%). Long-term compliance and preoperative erectile dysfunction were independent predictors of potency return after adjusting for age and nerve sparing. CONCLUSIONS The high cost of medication remains a significant barrier to maintaining therapy. Noncompliance to PDE5I therapy in a tertiary care centre was much higher than reported in clinical trial settings. With longer-term follow-up, we need to further define the factors that improve overall recovery of sexual function after RAP. [source]