Graft versus host disease (GVHD) is one of the common complications after stem cell transplant. This is a complication, which happens when the new stem cells from the donor attack other cells in the body of the transplant recipient.

Recently, an antibody (protein) called alemtuzumab or Campath has been found to be effective in the prevention of Graft vs. Host Disease.

Previous studies have shown a low risk of GVHD with alemtuzumab, however the risk of disease recurrence was high. Previous studies have used a high dose of alemtuzumab. The purpose of this study is:

• To find if by lowering the dose of alemtuzumab, can serious GVHD be prevented without increasing the risk of relapse (your condition getting worse).
• To find whether low dose of alemtuzumab in combination with cyclosporine can prevent GVHD more effectively when compared to current standard of care and does not increase the risk of recurrence.

Inclusion Criteria:

• Diagnosis of a hematological malignancy
• Peripheral blood as source of stem cells
• Able to give informed consent
• Availability of 6/6 matched sibling donor
• Fit for transplant using a conventional or reduced intensity approach

Exclusion Criteria:

• AST/ALT >3 x IULN at the time of transplant
• Serum creatinine > 1.5 x IULN at the time of transplant
• Prior allogeneic transplant
• Syngeneic donor
• Active uncontrolled infection
• HIV positive
• Pregnancy at the time of BMT