A Trial of Extracorporeal Photopheresis, Pentostatin, and Total Body Irradiation in Patients Undergoing Reduced Intensity Allogeneic Stem Cell Transplantation for the Treatment of Malignancies

Inclusion Criteria:

* Patients must give informed consent to receive study treatment.
* Availability of a suitable 5/6 (Class I mismatch) or 6/6 HLA-matched related or 10 or 10 matched unrelated donor.
* Adequate cardiac function with an ejection fraction ≥ 35% by echocardiography or nuclear cardiography within three months of transplantation
* Adequate pulmonary function with corrected DLCO ≥ 40% by pulmonary function testing within the past three months of transplantation
* Adequate renal function with creatinine clearance ≥ 30 ml/min. as calculated by the Cockroft and Gault method.
* Adequate hepatic function with AST, ALT, alkaline phosphatase, and total bilirubin no more than 3 x ULN unless related to neoplastic disease.
* Adequate vascular access, either by pheresis flow catheter or peripheral vein intravenous catheter, to perform ECP, should the patient be randomized to ECP.
* Patients with prior autologous stem cell transplantation are eligible.
* Age 18 to 75 years.
* Life expectancy of greater than 3 months.
* ECOG performance status of 0, 1, or 2.
* Platelet counts ≥ 20,000/microliter, with or without transfusion support, at the time of ECP, should the patient be randomized to ECP.
* Weight ≥ 40 kg.
* Systolic blood pressure ≥ 90 mmHg on the day randomization occurs
* Negative pregnancy test. The effects of ECP on the developing human fetus at the recommended therapeutic dose are unknown. For this reason, women of childbearing potential must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry and for the duration of study participation. Should a woman become pregnant or suspect she is pregnant while participating in this study, she should inform her treating physician immediately.
* Able to receive 600 cGy of total body irradiation. If patient previously treated by TBI then must be able to receive 400cGY of total body irradiation.
* Ability to understand and the willingness to sign a written informed consent document.

Exclusion Criteria:

* Hypersensitivity or allergy to 8-methoxypsoralen.
* Prior allogeneic stem cell transplantation
* HLA-DR mismatch or no worse than one antigen-mismatched unrelated donor.
* Patients with acute leukemia or acute lymphocytic leukemia with \> 5% circulating blasts in peripheral blood or \> 5% blasts in bone marrow aspirate and biopsy at the time of registration
* Patients with chemorefractory non-Hodgkin's lymphoma or Hodgkin's disease or multiple myeloma
* Diagnosis of myelofibrosis
* Patients known to be positive for antibodies to HIC or have evidence for active HIC viral replication.
* Participation in another clinical trial for prevention of GVHD.
* Patient is pregnant or lactating.
* Lack adequate vascular access for ECP.
* Systolic blood pressure \< 90 mmHg at the time of randomization, should the patient be randomized to ECP.
* Evidence of active, ongoing infection.
* Unwilling to comply with all study procedures.
* Unable or unwilling to give signed informed consent.