Real-world data with the use of caplacizumab in the treatment of acquired thrombotic thrombocytopenic purpura: A single-center with homogeneous treatment experience.

Background: Recently, real-world data confirmed the effectiveness of caplacizumab in the treatment of acquired thrombotic thrombocytopenic purpura (aTTP); however, limitations as different treatment protocols from multicenter experiences and the front-line use of rituximab could overshadow the real impact of the addition of caplacizumab.

Study Design And Methods: We report the clinical characteristics and response to treatment of 30 consecutive cases of aTTP treated under a homogeneous therapeutic protocol with the only exception of the addition of caplacizumab in the last 10 cases (caplacizumab group), whose primary outcome we compare with the previous 20 cases (control group).

Results: Caplacizumab was started at a median of 2.5 days after diagnosis (interquartile range [IQR] 1-4) and maintained for a median of 37.5 days (IQR 32-39). Safety was in line with previous reports with 30% of patients showing mild adverse events, the most common bleeding. The caplacizumab group achieved platelet count normalization after a median of 3 (IQR 2-5) versus 4 (IQR 2-8.5) days in the control group (p = .067). The caplacizumab group required a lower median number of plasma exchanges, 10 (IQR 9-11) versus 16.5 (IQR 11-20) in the control group (p = .0053) and a shorter length of hospitalization, 12 (IQR 12-14) vs. 22 (IQR 15-27) days (p = .0025). There were no refractory cases and no deaths in the caplacizumab group compared to five refractory cases and three aTTP-related death (15%) in the control group.

Discussion: Our experience confirms improvement in the outcomes with a decrease in refractoriness and mortality since the introduction of caplacizumab.