Clinical outcomes of a control group from a randomized controlled trial were successfully replicated by a synthetic control arm (SCA) based on historical controls, according to data presented at the 2019 American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago, Illinois.1
Adequate clinical trial enrollment can be challenging, and it is not uncommon for studies to be closed early due to low recruitment numbers. In addition, single-arm efficacy trials are sometimes required for difficult oncology indications, in rare diseases or populations, or for ethical or practical reasons. The goal of this study was to determine if an SCA can replicate a control arm, and, if so, what its potential applications could be.
The SCA was developed using data from historical clinical trials that were conducted using a similar experimental product and was statistically matched to the baseline characteristics of the experimental arm.
“We use statistical methods, most commonly propensity score matching, to select the historical patients who will form a composition of patients that match the baseline characteristics of the experimentally treated patients in our target trial,” Ruthie Davi, PhD, of Medidata Solutions, and lead author of the study, told Cancer Therapy Advisor. “In this way, we create something that looks a lot like a randomized control for a setting where randomization is problematic,” she said.