Due to the competition of new drug research and clinical requirement, speeding up drug development and marketing requires faster and more flexible clinical trial design that meets the ethical requirements. Different adaptive designs have emerged in clinical trials of different stages and purposes, for trial efficiency improvement. Adaptive design is more widely used in the field of oncology. Compared with traditional design, adaptive design is more complicated and requires higher level of methodology from researchers. Therefore, implementing adaptive design requires careful consideration and adequate preparation. This paper aims to summarize the design of adaptive methods used in different trial stages so as to provide reference for clinical research designers and implementers.
Randomized controlled trial has been the "gold standard" for clinical trials, in which randomization serves as a fundamental principle of clinical trials and plays an important role in balancing covariates. The allocation probability in traditional design is fixed, while that in adaptive randomization can alter during the experiment according to the specified plan to achieve the purposes of balancing the sample size, maximizing the benefit of patient, or balancing covariates etc. In this study, the adaptive randomization methods applied in clinical trials are discussed to explore their advantages and disadvantages for providing reference for the randomization of clinical trials.
Randomization was the basis for the design and conduct of clinical trials. However, the traditional randomized controlled trials (RCTs) were often randomized in a fixed manner with unbalanced potential covariates, which spured researchers to develop a more flexible and practical randomization method. Thus, the adaptive randomization emerged as the time needed. In this paper, the application of adaptive randomization in clinical trials was introduced, and its key points of implementation, advantages and disadvantages were summarized. The development space of the adaptive randomization in clinical applications was also discussed, and it provided evidence for the development of the drug clinical trials in China.