Carfilzomib inhibits proteasomes, which are responsible for intracellular protein homeostasis. specifically, it is a potent, selective, and irreversible inhibitor of chymotrypsin-like activity of the 20s proteasome, leading to cell cycle arrest and apoptosis.indicationsmultiple myeloma, relapsed/refractory: treatment (monotherapy) of relapsed or refractory multiple myeloma in patients who have received 1 or more lines of therapy- treatment of relapsed or refractory multiple myeloma (in combination with dexamethasone or lenalidomide plus dexamethasone) in patients who have received 1 to 3 prior lines of therapy.