Real-world experience with caplacizumab in the management of acute TTP

Abstract The cornerstone of life-saving therapy in immune-mediated thrombotic thrombocytopenic purpura (iTTP) has been plasma exchange (PEX) combined with immunomodulatory strategies. Caplacizumab, a novel anti–von Willebrand factor nanobody trialed 2 multicenter randomized controlled trials (RCTs) leading to European Union and US Food Drug Administration approval, available the United Kingdom (UK) through patient access scheme. Data were collected retrospectively from 2018 2020 for 85 patients (4 children) receiving caplacizumab 22 UK hospitals. Patient characteristics outcomes real-world clinical setting compared trial end points historical precaplacizumab era. Eighty-four received steroid rituximab alongside PEX; 26% required intubation. Median time platelet count normalization (3 days), duration PEX (7 hospital stay (12 days) comparable RCT data. initiation favorable (P < .05). Thrombotic (TTP) recurred 5 patients; all had persistent ADAMTS13 activity IU/dL. Of 31 adverse events 26 patients, 17 (55%) bleeding episodes, (16%) (2 unrelated caplacizumab); mortality was 6% (5/85), no deaths attributed caplacizumab. In 4 deaths, introduced >48 hours after (3-21 days). This evidence represents first largest series TTP including pediatric outside trials. Representative true practice, findings provide valuable information clinicians treating globally.