Duration of caplacizumab treatment after end of PEX in relation to outcome. Caplacizumab treatment duration after PEX stratified according to ADAMTS13 activity at the time of stopping caplacizumab. Nonfavorable outcomes include exacerbation, relapse, and death. Two cases were censored due to ongoing caplacizumab treatment and registered as being in remission at the time point of the census. It is noteworthy that in 6 cases, >1 instance of termination of caplacizumab treatment after PEX was reported. Days of caplacizumab treatment do not necessarily reflect the doses of caplacizumab because some patients were treated with a nondaily or intermittent caplacizumab regimen.