To evaluate response to esketamine nasal spray plus an oral antidepressant (ESK + AD) at day 28 in patients with major depressive disorder () and treatment-resistant depression (TRD) who did not meet response criteria within the first week of treatment. The current study is a pooled post hoc analysis of two phase 3, double-blind, active-controlled studies, conducted between August 2015 and February 2018, comparing ESK + AD with an oral antidepressant plus placebo (AD + PBO). Early treatment response was defined as a ≥ 50% decrease in Montgomery-Åsberg Depression Rating Scale total score at day 2 or days 2 and 8.
View Article and Find Full Text PDFImportance: Atabecestat, a nonselective oral β-secretase inhibitor, was evaluated in the EARLY trial for slowing cognitive decline in participants with preclinical Alzheimer disease. Preliminary analyses suggested dose-related cognitive worsening and neuropsychiatric adverse events (AEs).
Objective: To report efficacy, safety, and biomarker findings in the EARLY trial, both on and off atabecestat treatment, with focus on potential recovery of effects on cognition and behavior.
Morrissey, McEntegart, and Lang (2010) showed that in multicenter studies with equal allocation to several treatment arms, the modified Zelen's approach provides excellent within-center and across-study balance in treatment assignments. In this article, hierarchical balancing procedures for equal allocation to more than two arms (with some elements different from earlier versions) and their unequal allocation expansions that incorporate modified Zelen's approach at the center level are described. The balancing properties of the described procedures for a case study of a multiregional clinical trial with 1:2 allocation where balance within regions as well as in other covariates is required are examined through simulations.
View Article and Find Full Text PDFIn open-label studies, partial predictability of permuted block randomization provides potential for selection bias. To lessen the selection bias in two-arm studies with equal allocation, a number of allocation procedures that limit the imbalance in treatment totals at a pre-specified level but do not require the exact balance at the ends of the blocks were developed. In studies with unequal allocation, however, the task of designing a randomization procedure that sets a pre-specified limit on imbalance in group totals is not resolved.
View Article and Find Full Text PDFProschan, Brittain, and Kammerman made a very interesting observation that for some examples of the unequal allocation minimization, the mean of the unconditional randomization distribution is shifted away from 0. Kuznetsova and Tymofyeyev linked this phenomenon to the variations in the allocation ratio from allocation to allocation in the examples considered in the paper by Proschan et al. and advocated the use of unequal allocation procedures that preserve the allocation ratio at every step.
View Article and Find Full Text PDFWe propose a Bayesian adaptive two-stage design for the efficient estimation of the maximum dose or the minimum effective dose in a dose-finding trial. The new design allocates subjects in stage two according to the posterior distribution of the target dose location. Simulations show that the proposed two-stage design is superior to equal allocation and to a two-stage strategy where only one dose is left in the second stage.
View Article and Find Full Text PDFThe demand for unequal allocation in clinical trials is growing. Most commonly, the unequal allocation is achieved through permuted block randomization. However, other allocation procedures might be required to better approximate the allocation ratio in small samples, reduce the selection bias in open-label studies, or balance on baseline covariates.
View Article and Find Full Text PDFStudy Objective: To explore the effect of gaboxadol on NREM EEG in transient insomnia using power spectral analysis and evaluate the response between men and women.
Methods: This was a randomized, double-blind, 3-way, parallel-group transient insomnia study in 22 sleep laboratories. After a baseline night (N1), subjects underwent a 4-h phase-advance of their habitual sleep time the following night (N2).
Modified Zelen's approach is a randomization technique useful in multi-center trials where balance in treatment assignments within a center is desired. It has great balancing properties in a study with equal allocation to several treatment arms. This technique can also be used in studies with unequal allocation, where it would provide an allocation ratio close to the targeted one within centers as well as across centers.
View Article and Find Full Text PDFWe considered design issues for multiple treatment arms in survival intervention trials and used optimal design theory to allocate patients adaptively in such trials. We proposed three types of optimal designs: one ensures that we have the most precise estimates of the treatment effects, another guarantees that we have the minimal sample size subject to user-specified allocation ratio assignments among treatment arms, and the third ensures that the design has minimal total hazard for the cohort. The latter two types of optimal designs are also subject to user-specified power constraints for testing contrasts among treatment effects.
View Article and Find Full Text PDFStudies with unequal allocation to two or more treatment groups often require a large block size for permuted block allocation. This could present a problem in small studies, multi-center studies, or adaptive design dose-finding studies. In this paper, an allocation procedure, which generalizes the maximal procedure by Berger, Ivanova, and Knoll to the case of K≥2 treatment groups and any allocation ratio, is offered.
View Article and Find Full Text PDFBackground: The efficacy of oral montelukast has been well established in asthma and allergic rhinitis in adults and children. The purpose of this study was to evaluate dose-related bronchodilation and tolerability of inhaled montelukast.
Methods: Randomized, double-blind, crossover, adaptive-design study comparing single-dose administration of inhaled montelukast versus placebo in patients age 15-65 years with chronic asthma (n = 68).
Objective: The performance characteristics of hyaline articular cartilage measurement on magnetic resonance imaging (MRI) need to be accurately delineated before widespread application of this technology. Our objective was to assess the rate of natural disease progression of cartilage morphometry measures from baseline to 1 year in knees with osteoarthritis (OA) from a subset of participants from the Osteoarthritis Initiative (OAI).
Methods: Subjects included for this exploratory analysis are a subset of the approximately 4700 participants in the OAI Study.
Objective: The purpose of this study was to investigate the prognostic significance of Her-2 neu status in elderly patients managed with breast conservation strategy for stage I-II breast cancer.
Methods: We conducted an IRB approved retrospective review of 153 women age 70 and older with stage I-II breast cancer, managed with wide local excision and breast radiation between January 1997 and December 2002. The subset of 106 patients had a known Her-2 neu status and was analyzed for primary patient and tumor characteristics.