Non-myeloablative approach for allogeneic transplant is a reasonable option, especially given that the median age at diagnosis is 55-60 years and frequently present compromised skin in these patients, which increases the risk of infection. Therefore, we propose a clinical study with allogeneic hematopoietic stem cell transplantation (HSCT) using a unique non-myeloablative preparative regimen, TLI/ATG, to treat advanced mycosis fungoides/Sezary syndrome (MF/SS).

Primary Objectives

-To evaluate the graft versus lymphoma effect by monitoring rate of clinical response, event-free and overall survival.

Secondary Objectives

-To evaluate the incidence and extent of acute and chronic graft-versus-host disease (GVHD) and time to engraftment.

Inclusion Criteria:

1. Stage IIB-IV mycosis fungoides or Sezary syndrome, who have failed at least 1 standard systemic therapy or are not candidates for standard therapy.
2. Pathology reviewed and the diagnosis confirmed at Stanford University Medical Center.
3. Age > 18 years and <= 75 years.
4. Karnofsky Performance Status >= 70%.
5. Corrected DLCO >= 40%
6. Left ventricle ejection fraction (LVEF) > 30%.
7. ALT and AST must be <= 3X normal. Total bilirubin <= 3 mg/dL unless hemolysis or Gilbert's disease.
8. Estimated creatinine clearance >= 50 ml/min.
9. Have a related or unrelated HLA-identical donor or one antigen/allele mismatched in HLA-A, B, C or DRB1.
10. Signed informed consent.
11. Patients with prior malignancies diagnosed > 5 years ago without evidence of disease are eligible.
12. Patients with a prior malignancy treated < 5 years ago but have a life expectancy of > 5 years for that malignancy are eligible.

Donor Inclusion Criteria

1. Age >=17.
2. HIV seronegative.
3. No contraindication to the administration of G-CSF.
4. Willing to have a central venous catheter placed for apheresis if peripheral veins are inadequate

Exclusion Criteria:

1. Uncontrolled active infection.
2. Uncontrolled congestive heart failure or angina.
3. Pregnancy or nursing patients will be excluded from the study.
4. Those who are HIV-positive will be excluded from the study due to high risk of lethal infection after hematopoietic cell transplantation.

Donor Exclusion Criteria

1. Serious medical or psychological illness.
2. Pregnant or lactating women are not eligible
3. Prior malignancies within the last 5 years except for non-melanoma skin cancers