Caplacizumab in pediatric immune thrombotic thrombocytopenic purpura: the UK TTP Registry experience.

Pediatric thrombotic thrombocytopenic purpura (TTP) is an ultrarare disease. Immune TTP (iTTP) is driven by anti-ADAMTS13 autoantibodies causing an imbalanced von Willebrand factor (VWF):ADAMTS13 axis, and rarer still in children, but potentially life-threatening. Caplacizumab is licensed for iTTP treatment in adults and adolescents aged ≥12 years who weigh ≥40 kg.