ChEBI: Carfilzomib is a synthetic tetrapeptide consisting of morpholin-4-acetyl, L-2-amino-4-phenylbutanoyl, L-leucyl and L-phenylalanyl residues joined in sequence with the C-terminus connected to the amino group of (2S)-2-amino-4-methyl-1-[(2R)-2-methyloxiran-2-yl]-1-oxopentan-1-one via an amide linkage. Used for the treatment of patients with multiple myeloma It has a role as an antineoplastic agent and a proteasome inhibitor. It is a tetrapeptide, a member of morpholines and an epoxide.NCI Thesaurus (NCIt): Carfilzomib is an epoxomicin derivate with potential antineoplastic activity. Carfilzomib irreversibly binds to and inhibits the chymotrypsin-like activity of the 20S catalytic core subunit of the proteasome, a protease complex responsible for degrading a large variety of cellular proteins. Inhibition of proteasome-mediated proteolysis results in an accumulation of polyubiquinated proteins, which may lead to cell cycle arrest, induction of apoptosis, and inhibition of tumor growth.