Final results of PX-171–003-A0, part 1 of an open-label, single-arm, phase II study of carfilzomib (CFZ) in patients (pts) with relapsed and refractory multiple myeloma (MM)

8504 Background: CFZ is a novel proteasome inhibitor of the epoxyketone class that exhibits a high level of proteasome selectivityand demonstrates antitumor activity in bortezomib (BTZ)-resistant MM pts in phase I studies. Methods: PX-171–003-A0 was an open-label, multicenter study that enrolled MM pts who relapsed from >2 prior therapies, failed BTZ and at least 1 immunomodulatory agent thalidomide (THAL) or lenalidomide (LEN), and were refractory to last treatment progressing on or within 60 d of last therapy or 6 mo in relapsed and refractory MM pts who failed available therapies. 26% of patients had at least an MR and median duration of >7 mo with this steroid- and anthracycline-sparing regimen. CFZ toxicities were manageable and importantly, exacerbation of pre-existing PN was rare. The study has been expanded to enroll an additional 250 pts in this unmet medical need population at an escalated dose, and treatment has been extended beyond a year. [Table: see text