Assessing adverse events in clinical trials during the era of the COVID-19 pandemic.

Interpretation of safety data for clinical trials that were ongoing at the onset of the COVID-19 pandemic or were started subsequent to the beginning of the pandemic may be affected in a variety of ways. Pandemic-related issues can influence the extent of study participation and introduce data collection gaps. A SARS-CoV-2 infection among study subjects as a post-randomization event may introduce a number of confounding factors that can alter the frequency of adverse events, in some cases appearing as an increase in the frequency of an adverse event associated with a study drug relative to a comparator. The authors discuss clinical challenges and statistical concerns, specifically the estimand framework, including examples for consideration, to address these challenges in safety evaluation wrought by the COVID-19 pandemic. Our aim is to shed light on the importance of starting an early dialogue among the drug development team on the evaluation of safety, critical for benefit-risk evaluation throughout the drug development process.