Advantages and Challenges with Multiple Expansion Cohort Design in Oncology Studies
Food and Drug Administration (FDA) has provided a new type of study design for conducting Phase I first-in-human oncology studies. This design, known as a multiple expansion cohort (MEC) design, allows the sponsor to have multiple experimental groups in a single study simultaneously. The FDA guidelines explain that objective of these specially designed trials can be the assessment of anti-tumor activity in a setting specific to the disease, finding safe dose in special populations, evaluating alternative schedules or doses etc.
A clinical trial that utilizes the MEC design has a lot of advantages over the clinical trial with a traditional design. Each group has a different objective as explained above, therefore, multiple objectives can be achieved in a single phase. This helps in better resource management as a sponsor can decide whether to proceed or to discontinue the drug development based on the Phase I study. Multiple expansion cohort designs enable the investigator to know early that in which population the drug is working effectively. The flexibility of this study design allows the sponsor to decide to discontinue the arm early with negative results and recruit more patients in the arm with a positive response. In this way, this design helps to shorten the development process time in half compared to the traditional designs.
Although the MEC design has various advantages over traditional designs, there are a few limitations. Multiple studies that utilized this study design faced the challenges to design statistical and monitoring methods. There is a requirement of implementing proper plans for monitoring and reporting of safety.