Current Phase II clinical data for ridaforolimus in cancer

Introduction: The PI3K/AKT/mammalian target of rapamycin (mTOR) pathway plays a critical role in controlling cellular metabolism, proliferation and cell cycle regulation. Constitutive activation of this pathway has been demonstrated in many tumor types. Targeting the PI3K/AKT/mTOR pathway is of increasing therapeutic interest. Areas covered: Ridaforolimus belongs to a class of agents known as the rapalogs, first-generation mTOR inhibitors, which inhibit mTORC1, a part of the mTOR complex. Both oral and intravenous formulations of this agent have been tested in Phase II clinical trials for the treatment of solid tumors and hematologic malignancies. Promising results have been seen in endometrial cancer and soft tissue and bone sarcomas. Expert opinion: This article summarizes the current clinical and biological data on the use of ridaforolimus emerging from these Phase II studies, and provides potential advantages and drawbacks of the mTOR inhibitors in the current clinical practice.