LAUSR

increased risk of morbidity and mortality. In the HERCULES phase 3 trial, treatment with caplacizumab in patients with TTP has been shown to normalize platelets with a median time of 2 69 days [95% confidence interval (CI), 1 89–2 83] vs. placebo 2 88 days (95% CI, 2 68–3 56; P = 0 01) and patients who received caplacizumab were 1 55 times as likely to have a normalization of the platelet count as those who received placebo. In addition, treatment with caplacizumab prevented the development of refractory TTP. Thus, caplacizumab results in a more rapid resolution of TTP episodes, rapidly improves thrombocytopenia, and prevents increased morbidity and mortality by decreasing the formation of microthrombosis. Possible side effects of caplacizumab including haemorrhage, epistaxis, headaches and cost of the medication may be a possible barrier to hospitals carrying this therapy in their pharmacy. Our case exemplifies the benefit of caplacizumab in refractory TTP when standard therapies did not help. Thus, when refractory TTP is recognized caplacizumab should be initiated to prevent increased risk of mortality.