Assessment of the safety and the efficacy of a tacrolimus modified release (MR4) based immunosuppressive regimen in stable liver transplant subjects converted on a 1:1 (mg:mg) basis from a Prograf® based immunosuppressive regimen.

Multicenter, open, single sequence crossover study. Subject Enrolment: Prograf® administered twice daily is replaced by Prograf as study medication, administered twice daily.

Six weeks Prograf-Treatment Phase to confirm compliance to regimen stability requirements (see Inclusion and Exclusion Criteria), and collection of data under Prograf treatment.

Conversion from Prograf (twice daily, morning & evening dosing) total daily dose to MR4 once daily (only morning dosing) on a 1:1 (mg:mg) basis on Day 1.

Twelve weeks MR4-Treatment Phase with study assessments for safety and efficacy.

Inclusion Criteria:

• Liver transplant at least 12 months prior to enrollment.
• Prograf® dose remained unchanged for a minimum of 12 weeks prior to enrollment and tacrolimus whole blood trough level measurements were in the range of 5-15 ng/mL.

Exclusion Criteria:

• Any unstable medical condition that could interfere with the study objectives in the opinion of the investigator.