Abstract: Mycophenolic acid (MPA), the active moiety of mycophenolate mofetil (MMF), is routinely used as an adjunct immunosuppressant therapy in renal transplantation. Although highly effective, MMF therapy is associated with significant gastrointestinal adverse effects. Enteric-coated mycophenolate sodium (EC-MPS) is an advanced formulation delivering MPA. The enteric coat dissolves at pH > 5 allowing for MPA delivery in the small intestine. A single-center, open-label, randomized, three-way crossover study of 24 stable Caucasian renal transplant patients receiving cyclosporine-based immunosuppression, compared the relative bioavailability of two EC-MPS doses (640 and 720 mg) with MMF (1000 mg). Both EC-MPS doses delivered bioequivalent mean MPA exposure (AUC0−∞) compared with 1000 mg MMF: 60.7 μg h/mL for 640 mg EC-MPS, 66.5 μg h/mL for 720 mg EC-MPS, and 63.7 μg h/mL for 1000 mg MMF. Median tmax was significantly delayed for both EC-MPS doses compared with MMF (2.0 h vs. 0.75 h, respectively; p < 0.01), consistent with a functional enteric coating of EC-MPS. Furthermore, both EC-MPS doses were bioequivalent to 1000 mg MMF for AUC and Cmax for mycophenolic acid glucuronide. All three treatments were well tolerated. The EC-MPS 720 mg dose most closely approximated the MPA exposure of 1000 mg MMF and was selected for subsequent phase III studies.