If you are found to be eligible to take part in this study, you will be admitted to the hospital for treatment. Alemtuzumab will be injected into your vein over a period of 4 hours. This will be done 5 days in a row (Days 1 to 5). Drugs diphenhydramine (Benadryl), solumedrol and acetaminophen (Tylenol) will be given in to decrease the risk of or ease side effects before each dose of the alemtuzumab.