Carfilzomib (formerly PR-171) is a tetrapeptide epoxyketone-based irreversible inhibitor of the 20S proteasome. This second-generation proteasome inhibitor (PI) is structurally and mechanistically different to the dipeptide boronic acid PI, bortezomib. Compared to bortezomib, carfilzomib showed less off-target activity that may account for the reduced myelosuppression and reduced neuropathy that is observed compared to bortezomib. As monotherapy, carfilzomib has demonstrated robust and durable activity in heavily pre-treated patients with RRMM in phase I and II trials The idea of combining a PI and an immunomodulatory drug (IMiD) such as thalidomide or lenalidomide is attractive in MM due to the efficacy previously demonstrated with combination bortezomib, thalidomide and dexamethasone. Such efficacy obviates the need for chemotherapy that is known to induce genetic instability and in turn gives rise to secondary cancers. In combination with lenalidomide (25mg), Niesvizky and colleagues have demonstrated a maximum planned dose (MPD) of carfilzomib as 20/27 mg/m2 with promising safety and efficacy. Combination carfilzomib and thalidomide, as opposed to lenalidomide, is practically a more affordable regimen that will be more applicable to the Asia-Pacific region.