PB0302 - Caplacizumab Treatment for Acquired Thrombotic Thrombocytopenic Purpura: Comparative Real-world Multicenter Study

Sunday, July 10, 2022

6:30 PM – 7:30 PM

Location: Exhibition

Presentation Format: In-Person

Presenting Author(s)

Eleni Gavriilaki, MD PhD

Post-doctoral Researcher
G Papanicolaou Hospital, Thessaloniki, Greece
Thessaloniki, Thessaloniki, Greece

Co-Author(s)

EK

Evaggelia-Evdoxia Koravou

Researcher
G Papanicolaou Hospital
Thessaloniki, Thessaloniki, Greece
SB

Sotiria Besikli

Hematology Fellow
G Papanicolaou Hospital
Thessaloniki, Thessaloniki, Greece
TC

Thomas Chatziconstantinou

Hematology Fellow
G Papanicolaou Hospital
Thessaloniki, Thessaloniki, Greece
EN

Emmanuel Nikolousis

Professor
Athens Medical Center
Athens, Attiki, Greece
AM

Anastasia Mpanti

Hematologist
Papageorgiou Hospital
Thessaloniki, Thessaloniki, Greece
CP

Charalampos Pontikoglou

Professor
University of Crete
Heraklion, Iraklion, Greece
CK

Christina Kalpadaki

Hematology Lab.
University Hospital of Iraklion
Iraklion, Iraklion, Greece
AB

Aikaterini Bitsani

Hematologist
Laiko University Hospital
Athens, Attiki, Greece
IT

Ilianna Tassi

Hematologist
University Hospital of Ioannina
Ioannina, Ioannina, Greece
TT

Tasoula Touloumenidou

Biologist
G Papanicolaou Hospital
Thessaloniki, Thessaloniki, Greece
MP

Maria Papathanasiou

Hematologist
G Papanicolaou Hospital
Thessaloniki, Thessaloniki, Greece
AS

Antonia Syrigou

Hematologist
G Papanicolaou Hospital
Thessaloniki, Thessaloniki, Greece
GK

Georgia Kaiafa

Professor
Aristotle University of Thessaloniki
Thessaloniki, Thessaloniki, Greece
EK

Eleni Kapsali

Professor
University Hospital of Ioannina
Ioannina, Ioannina, Greece
EP

Eleni Papadaki

Professor
University of Crete
Heraklion, Iraklion, Greece
AA

Achilles Anagnostopoulos

Hematologist
G Papanicolaou Hospital
Thessaloniki, Thessaloniki, Greece
CL

Chrysavgi Lalayanni

Hematologist
G Papanicolaou Hospital
Thessaloniki, Thessaloniki, Greece
IS

Ioanna Sakellari

Hematologist
G Papanicolaou Hospital
Thessaloniki, Thessaloniki, Greece

Background: Caplacizumab is the first approved targeted therapy of acquired thrombotic thrombocytopenic porphyra (aTTP).

Aims: We designed this multicenter real-world study to assess safety and efficacy of caplacizumab compared to historic controls.

Methods: We recorded clinico-biological data from consecutive adult aTTP patients that were treated with corticosteroids and plasma exchange over the last decade (2011-2021) according to international guidelines. Diagnosis was confirmed with ADAMTS13 activity. Results are presented as median (range).

Results: We studied 63 patients [aged 48 (19-75) years]: 16 in the caplacizumab and 47 in the historic control group. The latter had a higher rate of neurological involvement (p=0.017). Rituximab was given in the majority of patients for refractory disease (2/3 patients with refractory disease in the caplacizumab group versus 15/16 in controls, p=0.161) or as pre-emptive treatment (12/13 in caplacizumab versus 15/29 in controls, p=0.011). No other significant differences were observed in patient or disease characteristics between groups.
Caplacizumab was given at a median day 4 (1-32) from diagnosis of acute phase (10 mg daily) for 31 (6-40) doses. There were no major hemorrhages or other complications. Plasma exchange sessions were 12 (9-21) in caplacizumab versus 14 (6-32) in controls. ADAMTS13 activity normalized after treatment in all caplacizumab patients and no relapses have been observed. Control patients presented a median of 1 (0-14) relapse. With 15.4 (2.2-320) months from disease diagnosis, there were 4 deaths (only from the control group, p-0.310, Figure).

Conclusion(s): Given the limited international experience, our study confirms safety and efficacy of caplacizumab in aTTP. Modifications of dosing compared to the clinical trial setting seem to have non-inferior outcomes in the real-world setting. Since ADAMTS13 remission has emerged as an important marker of long-term results, further studies in large real-world populations with longer follow-up are needed to highlight the value of caplacizumab.