Patients had to have a cardiac ejection fraction greater than 40%. For inclusion, patients had to have estimated creatinine clearance greater than 40 mL/min, bilirubin less than two times the upper limit of normal, and ALT/AST less than 2.5 times the upper limit of normal. Inclusion criteria also required adequate pulmonary function, defined as hemoglobin-corrected diffused capacity of carbon monoxide of at least 40% and forced expiratory volume in one second of 50% or greater.
Patients’ donors had to be either siblings, or 7/8 or 8/8 human leukocyte antigen-matched unrelated donors.
The patients receiving tacrolimus/methotrexate who served as controls were also collected prospectively, from centers that were not participating in the three-arm clinical trial. These patients also received reduced intensity conditioning and a peripheral blood stem cell transplant. This arm of the study was run through the Center for International Blood & Marrow Transplant Research. “I want to stress that the entry criteria were the same as for the intervention arms of the study,” Dr. Bolaños-Meade said.
Using a baseline rate of 23% for the GRFS endpoint, Dr. Bolaños-Meade and his collaborators established the size of the intervention and control arm so that the study would have 86%-88% power to detect a 20% improvement in the rate of GRFS over the contemporary control GVHD prophylaxis.