East® SurvAdapt
Adaptive Sample Size Re-Estimation Survival Studies for East®
Design, Simulate and Monitor Sample Size Re-Estimation Trials
East® SurvAdapt is an East® software system option for designing and monitoring clinical trials allowing alteration of the sample size based on an unblinded interim analysis. East® SurvAdapt facilitates superiority designs where planners either know the accrual duration and one of either the accrual rate, or the study duration.
Lesser sample size re-estimation methods require the use of a weighted statistic for the final analysis to preserve the type-1 error. This is non-intuitive and confusing to medical practitioners, requiring the down-weighting of data contributed by one set of patients relative to the others.
The methods of Chen, DeMets and Lan (2004), and Gao, Ware and Mehta (2008) eliminate the need for a weighted statistic. These methods and the adaptive designs resulting from East® SurvAdapt have proven acceptable to international regulators and validated in clinical practice.
What is a "Promising Zone" Adaptive Approach?
Cytel’s East® SurvAdapt makes practical the formulation of "Promising Zone" designs based on sample size re-estimation - based on single or multiple interim analysis. This technique can serve to "de-risk" later stage development by predeterming the interim results criteria to justify any additional enrollment and expense commitments. Click for an example of an FDA-accepted sample size re-estimation adaptive study utilizing a "Promising Zone"
East® SurvAdapt capabilities include:
- Intuitive access to the Chan, DeMets, Lan (CDL) Cui, Hung & Wang (CHW) adaptive methods
- Powerful trial simulations engine based on either CDL or CHW methods
- Vary accrual patterns, dropout patterns, piecewise hazard rates
- Incorporate an initial "go/no-go" group sequential component
- Tools to determine optimal interim analysis schedule
- The Conditional Power calculator (below)
Please contact us to better understand how East® SurvAdapt can help your team harness the power of adaptive sample-size re-estimation.