[Impact of mycophenolate mofetil prophylaxis duration on acute graft-versus-host disease after haploidentical stem cell transplantation].

Objective: To investigate the impact of mycophenolate mofetil (MMF) prophylaxis duration on acute graft-versus-host disease (aGVHD) after haploidentical stem cell transplantation (haplo-HSCT) using 'Beijing Protocol'. Methods: Adult patients (≥14 years) received haplo-HSCT in Peking University Institute of Hematology from Sep, 2016 to Mar, 2017 were retrospectively reviewed if they fulfilled the criterias: ①diagnosed with hematological maligancies; ②standard-risk status at haplo-HSCT. A total of 237 patients [including 102 patients with long MMF duration (defined as started on day -9 with 100 mg/d, adjusted to 500 mg/d from day +30 and discontinued on day +45 to +60 or occurrence of CMV/EBV reactivation or late-onset hemorrhagic cytitis), and 135 patients with short MMF duration (defined as started on day -9 with 500 mg/d and discontinued on the day achieved neutrophil engraftment)] were reviewed. The incidence of aGVHD, virus infection and overall survival (OS) were compared between the two groups. Results: The median durations of MMF prophylaxis of long and short duration groups were 27(7-71) and 15(9-24) days, respectively after haplo-HSCT. There were no differences of baseline characteristics (including sex, patient age, disease, mismatched HLA loci, donor-recipient relation, donor-recipient sex and donor age) between the two groups. The incidences of the grade Ⅱ-Ⅳ and Ⅲ/Ⅳ aGVHD in long and short duration groups were 31.1% versus 17.6% ( P =0.018) and 7.4% verus 7.8% ( P =0.900), respectively. The duration of MMF prophylaxis was not found to be associated with gradeⅡ-Ⅳ aGVHD by the multivariate analysis. There were no significant differences in terms of CMV viremia, EBV viremia, hemorrhagic cytitis and OS between the two groups. Conclusion: Prophylaxis with short duration MMF in the setting of 'Beijing protocol' haplo-SCT was not associated with increased acute GVHD with no impact on OS, which indicated that short duration MMF might be a feasible GVHD prophylaxis regimen.