Optimal Adaptive Designs in Phase III Clinical Trials for Continuous Responses with Covariates

A numerical study for comparing two response-adaptive designs for continuous treatment effects

“…In Bandyopadhyay and Biswas (2001) and in Biswas and Basu (2001) a sequential design τ for comparing mean responses after treatments is proposed which accommodates for robust estimates of the means of response distributions.…”

“…Among the few exceptions, are the design proposed by Bandyopadhyay and Biswas (2001), further explored in Biswas and Basu (2001), and the design based on the randomly reinforced urn introduced in Muliere et al (2006a). In this paper we will compare these two adaptive designs for clinical trials with responses on the continuous scale: details on the designs and their definitions are given in the next section after setting the probabilistic stage for the analysis.…”

On a Class of Optimal Type Covariate Adjusted Response Adaptive Allocations for Normal Treatment Responses

“…Although Jennison and Turnbull (2000) provided an unified approach to find an allocation ratio as a trade off between the ethical need of optimizing a clinically relevant criteria (e.g., number of allocations to the inferior treatment, total expected response or number of failures) and preservation of power for testing the equality of treatment effects, ignored the possibility of any covariate information. Along the line of Jennison and Turnbull (2000), Biswas and Mandal (2004) made an attempt to incorporate covariate information with an aim to minimise treatment failure but ignored the assessment of the so claimed optimality. It is worth mentioning at this point that, recently Azriel et al (2012) derived an optimal proportion considering only the maximization of power of a test of equality of treatment effects but in the context of covariate independent binary response trials.…”

“…But the effect of such interactions under a response adaptive set up is not explored completely. In fact, most of the works related to covariate either ignored the possibility of such interactions (e.g., Bandyopadhyay and Biswas (2001), Biswas and Mandal (2004)) or, if incorporated, avoid to assess the effect in details. However, the ethical goal consists always in assigning a greater fraction of subjects to the better performing treatment independently of the presence or absence of treatment-covariate interaction.…”

Optimal Response‐Adaptive Designs for Normal Responses

“…An optimal design for binary responses is given by Rosenberger et al (2001) and an optimal design for continuous responses is provided by Biswas and Mandal (2004). Recently, Zhang and Rosenberger (2006) [ZR] provided another design for normal responses.…”