Phase II Trial of Pentostatin in Steroid Refractory Acute Graft Versus Host Disease

Inclusion Criteria: * Must have biopsy proven grade II-IV acute GVHD refractory to systemic corticosteroids * No chronic GVHD * Age ≥ 18 years * Evidence of myeloid engraftment (ANC ≥ 0.5 x 109/l) * Performance status 0-3 Exclusion Criteria: * Patients on mechanical ventilation or who have resting O2 saturation \<90% by pulse-oximetry. * Patients on renal dialysis or who have an estimated creatinine clearance of \< 30 ml/min/1.73 m2. * Patients with documented clinical infection (progressive symptoms despite antibiotics or continued fever) cannot be enrolled on study until infection is controlled.