A Phase I Open-Label Study of the Effects of Tacrolimus and Cyclosporine on CP-690,555 in Healthy Volunteers

A Phase I, Open Label, Fixed-Sequence Study to Estimate the Effect of Tacrolimus and Cyclosporine on the Pharmacokinetics of CP-690,550 in Healthy Volunteers

A new immunosuppressive drug, based on the inhibition of important enzymes in the immune system, called JAK, is being developed by Pfizer to prevent transplant rejection. Since many treatments for transplant rejection may be administered together, this research study will analyze the effects of common transplant rejection therapies, Tacrolimus and Cyclosporine, on the JAK inhibitor, CP-690,550.

Inclusion Criteria:

• Healthy males between 21 and 55 years, inclusive.
• Healthy females of non-childbearing potential between 21 and 55 years, inclusive.
• Total body weight greater than 132 pounds.

Exclusion Criteria:

• Evidence or history of clinically significant disease
• Females of childbearing potential