Open AccessPF762 EFFECTS OF TWO DOSES OF ANTITHYMOCYTE GLOBULIN IN CONDITIONING REGIMENS FOR HAPLOIDENTICAL PERIPHERAL BLOOD STEM CELL TRANSPLANTATION
Author(s) -
wang M.,
fang X.,
jiang Y.,
sui X.,
li Y.,
liu X.,
wang X.,
xu H.,
wang X.
Publication year - 2019
Publication title -
hemasphere
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.677
H-Index - 11
ISSN - 2572-9241
DOI - 10.1097/01.hs9.0000561332.75221.e4
Subject(s) - thymoglobulin , medicine , cumulative incidence , gastroenterology , graft versus host disease , incidence (geometry) , transplantation , globulin , hematopoietic stem cell transplantation , anti thymocyte globulin , immunology , kidney transplantation , physics , optics
Background: Antithymocyte globulin (ATG), an important in vivo T‐cell depletion strategy, has been used for graft‐versus‐host disease (GVHD) prophylaxis and shown significant clinical benefit. However, the optimal ATG dose remains unclear. Aims: To assess the effectiveness of ATG at a total dose of 10.0 mg/kg and 7.5 mg/kg for haploidentical peripheral blood stem cell transplantation (PBSCT). Methods: We retrospectively analyzed patients who underwent haploidentical PBSCT, receiving myeloablative conditioning and standard GVHD prophylaxis. ATG (rabbit thymoglobulin) at a total dose of 10.0 mg/kg (2.5 mg/kg on days −5 to −2) and 7.5 mg/kg (2.5 mg/kg on days −4 to −2) were used in the two groups. Results: 40 and 35 patients were enrolled in the ATG‐10 and ATG‐7.5 groups, respectively. No significant difference was observed regarding the cumulative incidence of 100‐day grade II‐IV acute GVHD (20.0% vs 14.3%; p = 0.53) and 3‐year chronic GVHD (13.7% vs 15.7%; p = 0.83). The 3‐year probability of overall survival (OS) was 72.6% vs 74.4% (p = 0.81) and the 3‐year probability of GVHD‐free/relapse‐free survival (GRFS) was 69.0% vs 53.0% (p = 0.16). The incidence of relapse in the ATG‐7.5 group (30.9%) was higher compared with the ATG‐10.0 group (17.1%), but this difference was not statistically significant (p = 0.20). In multivariate analysis, the ATG dose was not associated with relapse, while no further respond to therapy (NR) before PBSCT predicted relapse (HR 1.19, p = 0.04). There were 5 patients (12.5%) and 8 patients (22.9%) in NR in the ATG‐10 and ATG‐7.5 groups, respectively (p = 0.19). Additionally, the ATG‐7.5 group had a trend for lower 300‐day incidence of EBV reactivation (92.5% vs 80.0%; p = 0.14) and CMV reactivation (90.5% vs 80.0%; p = 0.16), and lower 100‐day incidence of hemorrhagic cystitis (42.5% vs 28.6%; p = 0.15). Summary/Conclusion: 7.5 mg/kg ATG led to lower incidence of EBV reactivation, CMV reactivation and hemorrhagic cystitis without compromising control of grade II‐IV acute GVHD, chronic GVHD and OS when compared with 10.0 mg/kg ATG. Therefore, ATG at a dose of 7.5 mg/kg could be considered for further study.