The objective of this study is to compare the pharmacokinetic and pharmacodynamic properties and safety profile of alefacept in Caucasian and Japanese healthy subjects

Inclusion Criteria:

• Caucasian or Japanese healthy subject with a body mass index (BMI) of 18 to 29 kg/m2, inclusive
• Japanese subject is first generation, born in Japan from parents of Japanese decent, and has resided outside of Japan for 5 years or less OR Caucasian subject is Hispanic or non-Hispanic, born of parents of European decent (not Mestizo or mixed race)
• Subject must have clinical laboratory test results within the normal therapeutic range or, if abnormal, the results are not clinically significant as determined by the investigator

Exclusion Criteria:

• CD4+ lymphocyte count outside normal limits at Screening
• Received vaccine within 60 days prior to study drug administration
• History of drug or alcohol abuse within the 2 years prior to the study drug administration
• Treatment with any systemic immunosuppressant agent within 6 months prior to study drug administration
• Treatment with any antibody or biologic product within 6 months prior to study drug administration
• Treatment with any systemic steroid or steroid inhaler within 2 months prior to study drug administration
• A smoking habit of greater than 10 cigarettes a day