Sotrastaurin, a first-in-class protein kinase C (PKC) inhibitor, is aiming to become the first oral treatment that inhibits T-cell activation since the introduction of calcineurin inhibitors. T-cell activation is an early step in autoimmune diseases such as psoriasis and is also essential for the rejection of transplanted organs. Sotrastaurin blocks a pathway critical to T-cell activation and has shown promise in organ transplantation as well as in autoimmune disorders. Sotrastaurin is developed for the potential treatment of psoriatic skin lesions and graft rejection.