Comparison of Cyclosporine A and Mycophenolate Mofetil vs Cyclosporine A and Methotrexate in Reduced Intensity Conditioning HLA Sibling Allogeneic Stem Cell Transplantation. A Case-Match Single-Center Experience.

BACKGROUND: Graft-versus-host disease (GVHD) is the major obstacle to successful allogeneic stem cell transplantation (SCT) transplantation. Cyclosporine (Csa) in combination with methotrexate (MTX) is the most commonly used prophylactic regimen. The combination of CsA and Mycophenolate Mofetil (MMF) has recently been introduced. In this case-match study we retrospectively analyzed the introduction of MMF as GVHD prophylaxis in comparison with a short course of MTX in the setting of reduced intensity conditioning allogeneic SCT (Alo-RIC).

PATIENTS AND METHODS: We analyzed 59 Alo-RIC recipients who received an Alo-HSCT from an HLA-identical sibling between April 2000 and June 2006. The median follow-up for the whole group was 473 days (8 to 2139 days). The study group included 40 males and 19 females. Median age was 59 years (range 43 to 72). Diagnoses were acute leukemia/myelodisplastic syndrome) (n=19/22), mutiple myeloma (n= 6), chronic myeloid leukemia (n=5) and non- Hodgkin lymphoma (NHL) (n= 4). GVHD prophylaxis consisted of Csa/MTX (MTX group) in 37 patients and Csa/MMF (MMF group) in 22 patients. The conditioning regimen was based on fludarabine in combination with busulfan (42 recipients) or melfalan (17 cases).

RESULTS: The occurrence of mucositis grade 2–4 was higher in the MTX group than in the MMF group (62% vs 28% p= 0.015). No significant differences were found between MMF vs MTX groups in time to neutrophil recovery (16 +/−3 days vs 15 +/− 2days) (p= 0.5). Median time to the achievement of complete T-cell donor chimerism in the MTX and MMF groups was 79 days (range 19–740) and 76 days (range 24–223) respectively (P=0.4). The 1- year non-relapse mortality was similar in MTX and MMF groups 14% (95% C.L. 6–31%) vs 28% (95% C.L. 13–60%) respectively; P=0.2. Cumulate incidence of acute GVHD for MTX and MMF groups was 49% (95% C.L. 35–68%) and 68% (95% C.L. 51–91%) respectively (P= 0.6). Patients in the MTX group showed a trend to a higher incidence of chronic GVHD than the Csa/MMF group, 55% (95% C.L. 40–74%) vs 42% (95% C.L. 23–75%) (P=0.2). No differences were found between MTX vs MMF groups in 1-year overall survival [78%(64–92%) vs 53%(38–76%); P=0.1] nor in 1-year relapse incidence [37% (95%CI 21–64%) vs 19% (95%CI 10–37%) P=0.1) We conclude that the Csa/MMF combination appears to be equivalent to the standard Csa/MTX aGVHD prophylaxis in Alo-RIC. MMF showed significantly less mucositis.