A Phase 2 Trial of Rituximab and Corticosteroid Therapy for Newly Diagnosed Chronic Graft Versus Host Disease

Inclusion Criteria: * Children and adults with a new diagnosis of chronic GVHD- that requires systemic immunosuppressive treatment to a dose of 1mg/kg/day prednisone and who have undergone any type of donor hematopoietic cell graft or conditioning regimen. * Stable doses of other immunosuppressive medications (e.g. calcineurin inhibitors, mycophenolate mofetil) for 2 weeks prior to enrollment. In addition, these other immunosuppressive medications should not be dose increased. * Men and women of reproductive potential must agree to use an acceptable method of birth control during treatment and for six months after completion of treatment. * All subjects must provide written informed consent. Exclusion Criteria: * Known life-threatening hypersensitivity to Rituximab or other anti-B cell antibody. * Treatment with prednisone (or equivalent) at doses higher than 1 mg/kg/day at the time of enrollment. Persistent prednisone treatment of acute GVHD that is less than 1mg/kg is allowed. * Active, uncontrolled infection- CMV reactivation is excluded (i.e. pneumonitis, colitis). Peripheral blood CMV reactivation is allowed as long as it is not associated with CMV disease and is responding to therapy. * Known Hepatitis B surface Ag positive * Active malignant disease relapse. * Pregnancy * Lactating * Inability to comply with the Rituximab treatment regimen.