CYCLOPHOSPHAMIDE ANTITHYMOCYTE GLOBULIN CONDITIONING OF PATIENTS WITHSEVERE APLASTIC-ANEMIA FOR MARROW TRANSPLANTATION FROM HLA-MATCHED SIBLINGS - PRELIMINARY-RESULTS/

Many approaches have been taken to reducing the rate of graft failure and the incidence of graft-versus-host disease (GVHD) in bone marrow t ransplantation (BMT) of patients with severe aplastic anemia (SAA). Th e combination of cyclophosphamide with irradiation has had unequivocal success in reconstituting a sustained engraftment, but this procedure has severe associated risks such as second malignancies. Recently, cy clophosphamide (CYC) plus antithymocyte globulin (ATG) has been shown to be an effective alternative to irradiation-based programs in retran splants. Based on these experiences, the current clinical trial was st arted to prepare patients suffering from SAA for marrow transplantatio n from HLA-identical siblings with ATG plus CYC. Nine patients have be en enrolled into the study so far. They received a total dose of 200 m g/kg CYC and concomitantly 120 mg/kg or 90 mg/kg ATG, followed by cycl osporine plus methotrexate as post-transplantation GVHD prophylaxis. E ight of nine patients survived without any transplant-associated compl ications; i.e., they had a documented, stable engraftment without reje ction and without acute or chronic GVHD. One patient died due to an As pergillus sepsis prior to a definite engraftment. Although our data ar e preliminary because of the small number of patients enrolled and a f ollow-up of only 30 months, CYC plus ATG appears to be an effective pr eparative regimen for BMT in patients with SAA, resulting in a favorab le outcome.