Age affects GVHD rate but not overall survival in leukemia patients with posttransplant cyclophosphamide (PT-CY) and anti-thymocyte globulin (ATG) as GVHD prophylaxis

Mikhail Y. Drokov, Larisa A. Kuzmina, Natalia N. Popova, Ekaterina D. Mikhaltsova, Vera A. Vasilyeva, Olga M. Koroleva, Darya S. Dubnyak, Anna A. Sidorova, Ekaterina V. Usikova, Zoya V. Konova, Anna A. Dmitrova, Elena N. Parovichnikova, Valery G. Savchenko

National Research Center for Hematology, Moscow, Russian Federation

Summary

Introduction

Allogeneic bone marrow transplantation (allo-BMT) with high-dose posttransplant cyclophosphamide (PT-CY) to promote graft-host tolerance has become an alternative for standard immunosuppression. But sometimes unjustified toxicity expectations in aged patients are the main limiting factor of allo-HSCT for this group. Here we report our data about an influence of age on allo-HSCT results in leukemia patients in CR with PT-CY and ATG as GVHD prophylaxis.

Patients and methods

Forty patients with acute leukemia in CR transplanted in NRCH from mismatched unrelated donor were included in this study. All patient characteristics are listed in Table 1. All the patients received ATG at a dose 40 mg/kg from day -4 to day -1; PT-CY at dose 50 mg/kg daily at day +3,+4; Cyclosporine A 3 mg/kg from day -1 and MMF 3000 mg b.i.d from day +5. Kaplan-Meier estimator was used to determine overall survival, probability of aGVHD and relapse. The log-rank test was used to compare differences between the two groups. P-value less than 0.05 was considered statistically significant.

Results

Acute GVHD rates in 50+ y.o. group are significantly higher (Fig. 1) than in younger patients (66.7% vs 25% vs 12.5%, p=0.0044). It can be explained by thymus function and use of MAC conditioning regimens in the last patient group. Despite that fact due to low relapse rate (Fig. 2) overall survival (Fig. 3) in 50+ y.o. patients looks comparable with younger patients (66.7% vs 65.6% vs 58.9% for 40-49 y.o., 50+ and 20-39 y.o. respectively).

Conclusion

Allo-HSCT still makes sense in 50+ y.o. patients, since the results are not worse than in younger patients. Usage of PT-CY and ATG as GVHD prophylaxis seems to be safe and effective approach even for aged leukemia patients.