Contemporary clinical trials
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Contemp Clin Trials · Jul 2012
A Bayesian adaptive design for multi-dose, randomized, placebo-controlled phase I/II trials.
We present a design for a randomized controlled trial (RCT) featuring two simultaneous iterative processes, dose escalation and cohort expansion. In this design, patient enrollment does not need to stop when transitioning from the evaluation of the dose safety and tolerability to the assessment of its efficacy. The cohort expansion used in dose-finding is adaptive, based on the interim comparisons between each dose and placebo. ⋯ Simulation studies also demonstrated that this proposed adaptive design controls the false positive error rate at the specified level and provides adequate statistical power to detect the treatment effect. Compared to the conventional approach, our proposed adaptive design removes ineffective doses, reduces the total sample size, and maintains adequate power for dose-finding. The proposed design has been implemented in an ongoing study and software for trial simulation is available at http://odin.mdacc.tmc.edu/~yuanj/soft.html.
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Contemp Clin Trials · Jul 2012
Randomized Controlled TrialAn online randomised controlled trial to assess the feasibility, acceptability and potential effectiveness of 'Living with Bipolar': a web-based self-management intervention for bipolar disorder: trial design and protocol.
Bipolar Disorder (BD) is a common and severe form of mental illness. Pharmacotherapy is the main treatment offered, but has limited effectiveness, and there is increasing evidence that people with BD respond well to psychological interventions. Inequalities in access to face-to-face psychological interventions mean many people seek support outside of routine health services. ⋯ The results of this trial will inform a definitive trial; and the implementation phase will aim to assess the potential for use within the NHS.
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Contemp Clin Trials · Jul 2012
Comparative StudyDose-finding designs in pediatric phase I clinical trials: comparison by simulations in a realistic timeline framework.
Usual dose-finding methods in oncology are sequential. Accrual is suspended after each group of patients to assess toxicity before increasing the dose. An adapted Continual Reassessment Method (CRM) and Rolling 6 (R6) method, designed to avoid this suspension of accrual in pediatric oncology, are compared with the traditional 3+3 design. ⋯ These new methods can reduce the number of skipped patients, but only provide limited gain in terms of ability to select the right dose. New designs are needed.
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Contemp Clin Trials · May 2012
Randomized Controlled Trial Multicenter StudyThe Pregnancy in Polycystic Ovary Syndrome II (PPCOS II) trial: rationale and design of a double-blind randomized trial of clomiphene citrate and letrozole for the treatment of infertility in women with polycystic ovary syndrome.
Polycystic Ovary Syndrome (PCOS) is a common cause of female infertility and first line treatment is currently oral clomiphene citrate, a selective estrogen receptor modulator, which results in both a high nonresponse rate and multiple pregnancy rate. Aromatase inhibitors such as letrozole may have more favorable ovarian and endometrial effects. The goal of the Pregnancy in Polycystic Ovary Syndrome II (PPCOSII) study is to determine the safety and efficacy of clomiphene citrate (CC) compared to letrozole, in achieving live birth in infertile women with PCOS. ⋯ After progestin withdrawal as needed, 750 women will be equally randomized to two different treatment arms: A) CC 50mg every day for 5 days (days 3-7 of cycle), or B) letrozole 2.5mg every day for 5 days (days 3-7 of cycle), for a total of 5 cycles or 25 weeks. The dose will be increased in subsequent cycles in both treatment groups for non-response or poor ovulatory response up to a maximum of 150 mg of CC a day (×5 days) or 7.5mg of letrozole a day (×5 days). The primary analysis will use an intent-to-treat approach to examine differences in the live birth rate in the two treatment arms.