The Cytel blog keeps you up to speed with the latest developments in biostatistics and clinical biometrics.

Recent Publication: A Gatekeeping Procedure to Test a Primary and a Secondary Endpoint in a Group Sequential Design with Multiple Interim Looks

February 15, 2018


A recent publication in Biometrics ‘A Gatekeeping Procedure to Test a Primary and a Secondary Endpoint in a Group Sequential Design with Multiple Interim Looks’ greatly extends the results of Glimm et al. ( 2010) and Tamhane et al ( 2010) which studied the problem of testing a primary and secondary endpoint, subject to a gatekeeping constraint, using a group sequential design (GSD) with K = 2 looks. This extends the methodology to provide for multiple (K>2) looks. The methodology is applied to the data from the RALES study (Pitt et al., 1999; Wittes et al., 2001).

Read More

Adaptive Designs in Practice

April 28, 2016

Adaptive Designs in Practice: Interview with NIHR Research Fellow Munya Dimairo

NIHR and University of Sheffield researchers recently published a paper, ‘Adaptive designs undertaken in clinical research: a review of registered clinical trials’(Hatfield et al) which explores the current state of adaptive designs in practice. In this blog we catch up with Munya Dimairo, NIHR Research fellow and one of the paper’s co-authors to find out more.

Read More

Clinical Development & Statistical Methodology for Cardiovascular Risk Assessment

February 3, 2015

A new publication co-authored by Cytel Co-Founder and President Cyrus Mehta considers a range of clinical development methods for cardiovascular outcome trials. Cardiovascular outcome trials, (often referred to as CVOTs), reflect safety standards implemented by the FDA and EMA to determine whether or not new drugs impose undue cardiovascular risk on patients. CVOTs typically occur after Phase 3 trials, and often make up for the slow rate of observed events by enrolling thousands of patients. This adds substantial delay in getting a drug to market.

In this paper, Cyrus and his co-authors explore how adaptive and group sequential methods might shorten this process without compromising the quality of the trial. In particular they consider increases in sample size and early stopping boundaries. They consider the possible benefits of unblinded sample size re-estimation (also known as the Promising Zone Design) in CVOT trials. 

Read More