Carfilzomib

Carfilzomib (PR-171) is a tetrapeptide epoxyketone and a selective proteasome inhibitor. Carfilzomib irreversibly binds to and inhibits the chymotrypsin-like activity of the 20S proteasome, an enzyme that degrades unwanted cellular proteins. Carfilzomib (PR-171) induced a dose- and time-dependent inhibition of proliferation, ultimately leading to apoptosis. Carfilzomib and its orally bioavailable analog oprozomib, effectively decreased MM cell viability following continual or transient treatment mimicking in vivo pharmacokinetics. In clinical trials, carfilzomib (PR-171) has exhibited potent anti-myeloma efficacy and decreased side effects compared with bortezomib. At clinically relevant concentrations, carfilzomib directly inhibited OC formation and bone resorption in vitro, while enhancing osteogenic differentiation and matrix mineralization. Carfilzomib is currently in a phase III confirmatory clinical trial, known as the ASPIRE trial, comparing carfilzomib, lenalidomide and dexamethasone versus lenalidomide and dexamethasone in patients with relapsed multiple myeloma.