Sirolimus and Mycophenolate Mofetil (MMF) as Graft Versus Host Disease (GVHD) Prophylaxis After Reduced Intensity Conditioning (RIC) Transplantation

The combination of tacrolimus and methotrexate is standard therapy for prevention of GVHD,
however, our recent experience has demonstrated that the substitution of sirolimus for
methotrexate provides superior GVHD control with reduced transplant-related toxicity. One
limitation to the use of calcineurin inhibitors in GVHD prevention is the disruption in Treg
function and proliferation. Based on our evolving understanding of the role of Treg in the
development of chronic GVHD, we propose a GVHD prophylactic regimen that is effective in
prevention of acute GVHD, but by virtue of the maintenance of Treg activity may be able to
prevent chronic GVHD. We hypothesize that the substitution of mycophenolate mofetil for
tacrolimus may provide similar protection against acute GVHD and prevent chronic GVHD while
minimizing renal toxicity after transplantation.

Inclusion Criteria:

1. Patients with hematologic malignancies, who are at high risk of complications after
conventional myeloablative transplantation

2. Patients must have a 6/6 matched, related donor. Matching at HLA Class II will be
based on PCR of sequence specific primers (SSP). Among family member transplants,
serologic matching at Class I is sufficient

3. Patient age greater than 18

4. Performance status 0-2

5. Life expectancy of > 100 days without transplantation

6. Written informed consent must be obtained in all cases from the patient

Exclusion Criteria:

1. Pregnancy

2. Prior Allogeneic Stem Cell Transplantation from any donor

3. Evidence of HIV infection or active Hepatitis B or C infection

4. Heart failure uncontrolled by medications

5. Total bilirubin > 2.0 mg/dl that is due to hepatocellular dysfunction

6. AST > 90

7. Cholesterol > 300 mg/dl or Triglycerides > 400 mg/dl while adequately treated

8. Uncontrolled bacterial, viral or fungal infection

9. Requirement for voriconazole at the time of hospital admission