Carfilzomib, a second-generation proteasome inhibitor, has been increasingly used in relapsed/refractory multiple myeloma (MM) since its approval by the American food and drug administration (FDA) in the summer of 2012. The drug is active as a single agent and in combination with other antimyeloma agents. ⋯ This review will give a comprehensive summary of the drug, including its mechanism of action, the evaluated doses and schedules as well as a summary of the main clinical trials in the relapsed/refractory and newly diagnosed settings. A focus will be placed upon certain subgroups of interest as well as a description of the toxicity associated with carfilzomib use and a clinical perspective on toxicity management.