Lubben, Jade Marie

8010 Background: Carfilzomib is a proteasome inhibitor that irreversibly binds its target with favorable toxicity profile that has shown significant activity in relapsed multiple myeloma (MM). Here we used carfilzomib as the center of a 4 drug induction regimen designed for MM patients pre stem cell transplant (SCT). Methods: We conducted a phase I safety run in 6 patients with no DLT observed before expanding to phase II. The phase II regimen is shown below. Treatment was for 4 cycles with expected SCT post induction. For the phase II portion of this trial, the primary endpoint is the proportion of patients who have ≥ very good partial response to treatment. All patients received herpes zoster prophylaxis and ASA daily. Results: Twenty seven patients were enrolled. Median age was 65 (range 27-74). ORR for evaluable patients (n=17) at phase II dosing is 100%: CR 35%, VGPR 48%, PR 18% after 4 cycles of CYCLONE. Grade 3 toxicity was reported in 52% of patients and 14% experienced a grade 4 toxicity. Grade 3/4 toxicities occurring in >5% of patients included fatigue, neutropenia, lymphopenia, thromboembolism, myopathy. Toxicities of any grade seen in >20% of patients included fatigue, constipation, lethargy, thrombocytopenia, somnolence, creatinine increased, malaise. Four patients (20%) developed grade 1 sensory neuropathy; no higher grade or painful neuropathy was evident. All patients are alive. All patients advancing to SCT successfully collected stem cells. One patient with t(4;14) disease who was not transplanted has progressed. 94% remain progression free. Conclusions: The 4 drug CYCLONE regimen has remarkable efficacy (83% ≥VGPR) and manageable toxicity in newly diagnosed patients with multiple myeloma. Especially notable was the low incidence of neuropathy and depth of response (CR 35%) after only 4 cycles. Given the relative lack of toxicity an extension of this regimen at higher doses of carfilzomib (20/45mg/m2) has been initiated. [Table: see text]