Real-World Data on Effectiveness and Safety of First-Line Use of Caplacizumab in Italian Centers for the Treatment of Thrombotic Thrombocytopenic Purpura: The Roscapli Study

<b>Background/Objectives</b>: Immune thrombotic thrombocytopenic purpura (iTTP) is a thrombotic microangiopathy caused by the formation of anti-ADAMTS13 antibodies. Caplacizumab is approved for the treatment of acute episodes of iTTP in conjunction with plasma exchange (PEX) and immunosuppression. Real-world data for the use of caplacizumab in Italy have been recently published by a limited number of centers located in the northern and middle regions of the country only. <b>Methods</b>: A total of 38 patients with iTTP were enrolled in the study in six Italian centers spread over the entire territory of the country. The patients' data were registered in eCRF. <b>Results</b>: All patients achieved normalization of platelet count (median 2.0 days, IQR: 2-4), within a time significantly shorter than in the absence of caplacizumab, as previously reported in other studies. As to the secondary aims, patients treated with caplacizumab had a few exacerbations (4/38 (10.5%)) and relapses (2/38, 5.3%). No deaths or refractoriness were observed in these patients. The total length of hospitalization was 12 days (IQR: 9-18) and only one patient required 2 days of stay in the intensive care unit. Interestingly, when caplacizumab was initiated within the first 3 days, the plasma exchange (PEX) duration was 9 days (IQR: 8-10), which was significantly lower than those reported in previous studies conducted in the absence of caplacizumab. No severe adverse event was described in the caplacizumab-treated patients. <b>Conclusions</b>: Caplacizumab reduced exacerbations and refractoriness compared with previously reported standard-of-care regimens. When administered in association with PEX and immunosuppressive therapy, caplacizumab provided rapid normalization of platelet count, which was responsible for lower overall hospitalization time, ICU stay, lower exacerbations and relapses compared to previously reported outcomes of studies carried out without caplacizumab.