Carfilzomib, a selective proteasome inhibitor, was approved in 2012 for the treatment of relapsed and refractory multiple myeloma. Safety data for single-agent carfilzomib have been analyzed for 526 patients with advanced multiple myeloma who took part in one of 4 phase II studies (PX-171-003-A0, PX-171-003-A1, PX-171-004, and PX-171-005). Overall analyses of adverse events and treatment modifications are presented, as well as specific analyses of adverse events by organ system. Overall, the most common adverse events of any grade included fatigue (55.5%), anemia (46.8%), and nausea (44.9%). In the grouped analyses, any grade adverse events were reported in 22.1% for any cardiac (7.2% cardiac failure), 69.0% for any respiratory (42.2% dyspnea), and 33.1% for any grouped renal impairment adverse event (24.1% increased serum creatinine). The most common non-hematologic adverse events were generally Grade 1 or 2 in severity, while Grade 3/4 adverse events were primarily hematologic and mostly reversible. There was no evidence of cumulative bone marrow suppression, either neutropenia or thrombocytopenia, and febrile neutropenia occurred infrequently (1.1%). Notably, the incidence of peripheral neuropathy was low overall (13.9%), including patients with baseline peripheral neuropathy (12.7%). Additionally, the incidence of discontinuations or dose reductions attributable to adverse events was low. These data demonstrate that single-agent carfilzomib has an acceptable safety profile in heavily pre-treated patients with relapsed/refractory multiple myeloma. The tolerable safety profile allows for administration of full-dose carfilzomib, both for extended periods and in a wide spectrum of patients with advanced multiple myeloma, including those with pre-existing comorbidities.
ABSTRACTpression including thrombocytopenia, and dose-limiting peripheral neuropathy (PN) (up to 30% Grade 1/2 and 7-15% Grade 3/4). The PN often leads to discontinuation, and can be debilitating and occasionally irreversible. [19][20][21] Thalidomide is even more strongly implicated in PN, 22 and a recent analysis of patients with newly diagnosed MM revealed that although thalidomide improved efficacy when added to melphalan-prednisone, it negatively impacted safety. 23 Maintenance therapy, as well as consolidation strategies, with many of these drugs are being investigated as important ways to improve and prolong responses in patients with MM, 24 and these extended treatment periods may draw increased attention to tolerability and cumulative toxicities when considering longterm treatment options.Carfilzomib was initially evaluated in 2 phase I studies 25 and PX-171-002
26) investigating two different dosing schedules: 5 consecutive days of a 14-day cycle and 2 consecutive days/week for 3 weeks of a 28-day cycle). Consecutive day dosing demonstrated promising antitumor activity. However, single-agent carfilzomib administered using the 2 consecutive day dosing schedule (PX-171-002) was better tolerated and was chosen for further exploration in ph...