IC-01. Posttransplant cyclophosphamide versus ATG for graft-versus-host disease prophylaxis in patients with inherited disorders undergoing allogeneic stem cell transplantation
Tatiana A. Bykova, Anna A. Osipova, Varvara N. Ovechkina, Ivan S. Moiseev, Alexander L. Alyanskiy, Elena V. Semenova, Ludmila S. Zubarovskaya
RM Gorbacheva Research Institute of Pediatric Oncology, Hematology and Transplantation, Pavlov University, St. Petersburg, Russia
Contact: Dr. Tatiana A. Bykova, e-mail: dr.bykova@mail.ru
Summary
Introduction
Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is performed as a curative treatment for children with non-malignant diseases. Graft-versus-host disease (GVHD) is a potentially life-threatening complication, which restricts opportunity for allo-HSCT. Usage of post-transplant cyclophosphamide (PTCy) has resulted in low incidence of both acute (aGVHD) and chronic GVHD (cGVHD). However, clinical data on PTCy efficacy and rates of primary graft failure are rather scarce for the children with inherited diseases. Our aim was to compare ATG vs PTCy-based GVHD prophylaxis in the patients (pts) with inherited disorders following allo-HSCT.
Patients and methods
The study included 83 pts, most of them were in childhood or at a young age (median of 3 y.o., at a range of 7 mo to 33 y.o.), with different types of inherited disorders (β-thalassemia, 3; bone marrow failure syndromes, 30; inherited metabolic disorders, 37; primary immunodeficiency disorders, 13) who were enrolled into a retrospective study. Donor types were as follows: matched/mismatched unrelated (MUD/MMUD), 68 cases; matched related donor (MRD), 8; haploidentical (haplo) transplants, 7 cases. Conditioning regimens were myeloablative (MAC) in 34 cases; reduced-intensity (RIC) regimen, in 49 pts. The graft source were: bone marrow (BM) in 61 cases, peripheral blood stem cells (PBSC), in 22 pts. Twenty-five pts received PTCy-based GVHD prophylaxis (50 mg/kg on days +3, +4); ATG-based GVHD prevention was applied in 58 pts.
Results
Median follow-up was 27 months (range 1 to 174). The five-year overall survival was 96% vs 61% in the PTCy and ATG groups (p=0.014). The incidence of primary graft failure was 8% vs 12% in the PTCy and ATG groups (p=0.62). Cumulative incidence (CI) of aGVHD grade 2-4 was 28% vs 46% (p=0.07), aGVHD 3-4 grade was seen in 0% vs 25% (p=0.008) in the PTCy and ATG groups, respectively. CI of chronic GVHD was 17% vs 39% in PTCy and ATG groups (p=0.2), extensive chronic GVHD was observed in 4% vs 23% (p=0.16).
Conclusion
We have currently found no differences in the incidence of primary graft failure after HSCT in the mentioned group. A significantly higher survival rate was observed in the PTCy group, due to low incidence of severe acute GVHD.
Keywords
Inherited disorders, allogeneic hematopoietic stem cell transplantation, posttransplant cyclophosphamide, graft failure, graft-versus-host disease.
