OC 14.5 - Plasma exchange-free management of immune thrombotic thrombocytopenic purpura: the Austrian-German experience

Sunday, June 25, 2023

11:45 – 12:00 ET

Room: 520

Session Available As: On-Demand

Presenting Author(s)

Lucas Kühne, MD (he/him/his)

Resident
Department II of Internal Medicine and Center for Molecular Medicine Cologne (CMMC), Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
Köln, Nordrhein-Westfalen, Germany

Co-Author(s)

Paul Knoebl, MD

Professor
Department of Medicine 1, Division of Hematology and Hemostasis, Medical University of Vienna, Vienna, Austria
Vienna, Wien, Austria
KE

Kathrin Eller

Professor
Division of Nephrology, Department of Internal Medicine, Medical University of Graz, 8036 Graz, Austria
Graz, Steiermark, Austria
VB

Veronika Buxhofer-Ausch

Professor
Department of Internal Medicine I with Hematology, Stem Cell Transplantation, Hemostaseology and Medical Oncology, Ordensklinikum Linz Elisabethinnen, Linz, Austria
Linz, Oberosterreich, Austria
PB

Paul T. Brinkkoetter

Professor
Department II of Internal Medicine and Center for Molecular Medicine Cologne (CMMC), Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
Cologne, Nordrhein-Westfalen, Germany
LV

Linus A. Völker

Consultant
Department II of Internal Medicine and Center for Molecular Medicine Cologne (CMMC), Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
Cologne, Nordrhein-Westfalen, Germany

Background: The approval of the anti-VWF nanobody caplacizumab has added a new principle to acute iTTP management, with a significantly reduced time to platelet count normalization. Since its approval, reports of plasma exchange-free iTTP management with caplacizumab and immunosuppression alone have increased, as caplacizumab rapidly dissolves features of thrombotic microangiopathy.

Aims: Here, we analyzed a management of acute iTTP, following an advanced treatment regimen that withholds plasma exchange (PEX) if platelet counts robustly increase to caplacizumab and aims for early addition of immunosuppression with steroids and rituximab.

Methods: We identified 43 patients (33 female, 10 male patients) with a total of 45 acute iTTP episodes and a median age of 38 years (range 20 to 83), treated in Austria and Germany between 2018 and 2022.

Results: All 43 patients had signs of thrombotic microangiopathy with (severe) organ dysfunction, severe ADAMTS13 deficiency and detectable anti-ADAMTS13 antibodies. We observed a robust increase in platelet count in the majority of patients, with a median time to initial platelet count normalization after caplacizumab start of 4 days (IQR 3-4 days, n = 23).
Three patients did not improve with platelet counts after the first caplacizumab dose and received additional PEX. Underlying conditions were identified, that may have hampered platelet recovery (CMV viremia, HIV, immune thrombocytopenia). One patient with recurrent TTP was first treated with plasma infusions due to a suspected cTTP and later switched to caplacizumab, once antibodies were detected. Four patients had exacerbations that were managed with caplacizumab alone, after initial standard of care treatment.

Conclusion(s): Our cohort clearly demonstrates at a larger scale that PEX is not mandatory for acute iTTP management, with clinical remission being achieved by caplacizumab and immunosuppression alone in the majority of patients. A new algorithm for iTTP management with the option to withhold PEX and observe the response to caplacizumab seems feasible.

Learning Objectives:

Upon completion, participants will be able to list benefits and limitations of plasma-exchange free management of immune thrombotic thrombocytopenic purpura.
Upon completion, participants will be able to describe the treatment response to plasma-exchange free management of acute immune thrombotic thrombocytopenic purpura, enabled by frontline treatment with caplacizumab and close patient monitoring.
Upon completion, participants will be able to identify situations, in which withholding plasma exchange and monitoring the response to caplacizumab may be feasible in TTP patients.