The purpose of this study is to assess the safety and effectiveness of a new oral immunosuppressant agent compared to standard care in renal transplant patients diagnosed with BK nephropathy.

The purpose of this study is to assess the efficacy and safety of FK778 compared with standard care in renal transplant recipients with newly diagnosed and untreated BK nephropathy.

Inclusion Criteria:

• Renal transplant recipient with newly diagnosed BK nephropathy.

Exclusion Criteria:

• Previous treatment for BK nephropathy
• Organ transplant other than kidney
• Uncontrolled concomitant infection other than BK nephropathy