Source Division of Transplantation, Department of Surgery, University of Alberta, 2D4.44 Mackenzie Center, University of Alberta, Canada T6G 2B7.

The development of calcineurin inhibitors (CNIs) led to marked improvements in patient and graft survival after liver transplantation (LTx). We have been left, however, with a dependence on immunosuppressive agents with nephrotoxicity, neurotoxicity, adverse impacts on cardiac risk profile, and risk for malignancy. These challenges need to be met against a dominance of hepatitis C virus (HCV) and hepatocellular carcinoma (HCC) as indications for liver transplant. Unmet needs for immunosuppression (IS) in LTx include: New immunosuppressives will need to address the above needs while supporting patient and graft survival equivalent to those achievable with CNIs, ideally without important new toxicities. Two new classes of agents are currently in advanced clinical development: belatacept, and the mammalian target of rapamycin inhibitors (m-TORi). This manuscript will review evidence for a role for m-TORi in LTx in a range of clinical scenarios including patients with CNI nephrotoxicity or neurotoxicity, patients at risk of (or with) HCV recurrence, and patients at risk of HCC recurrence.