Adoption of multiple primary endpoints in phase III trials of systemic treatments in patients with advanced solid tumours. A systematic review

•We describe the use of multiple primary endpoints (MPEs) in cancer phase III trials.•Out of 235 trials published between 2017 and 2020, 27 trials (12%) adopted MPEs.•Proportion of trials with MPEs increased over time, from 6% in 2017 to 20% in 2020.•Proportion of trials adopting MPEs was particularly high with immunotherapy (53%).•Many trials adopting MPEs do not respect recommendations by regulatory agencies.