Phase 1/2 study of weekly carfilzomib, cyclophosphamide, dexamethasone in newly diagnosed transplant-ineligible myeloma.

This multicentre, open-label phase 1/2 trial determined safety and efficacy of weekly carfilzomib plus cyclophosphamide-dexamethasone (wKCyd) in newly diagnosed multiple myeloma (NDMM) patients aged ⩾65 years or transplant ineligible. Patients received wKCyd for up to nine 28-day cycles, followed by maintenance with carfilzomib until progression/intolerance. The phase 1 portion used a 3+3 dose-escalation scheme to determine the maximum tolerated dose of weekly carfilzomib: 12 patients received wKCyd with carfilzomib doses of 45, 56 and 70 mg/m2. The recommended phase 2 dose was established at 70 mg/m2 and 54 patients (phase 1 and 2) received weekly carfilzomib 70 mg/m2: 85% of them achieved ⩾partial response (PR), 66% ⩾very good PR, 30%⩾near-complete response (CR) and 15% CR. Responses improved in 40 patients who started maintenance: 98% achieved ⩾PR, including 29% CR and 10% stringent CR. After a median follow-up of 18 months, the 2-year progression-free survival and overall survival rates were 53.2% and 81%, respectively. The most frequent grade 3-5 toxicities were neutropenia (22%) and cardiopulmonary adverse events (9%). This is the first study of weekly carfilzomib plus an alkylating agent in elderly patients with NDMM. wKCyd was effective, with an acceptable risk/benefit ratio, and thus can be a valid option in this setting.

Relevance of sample preparation for flow cytometry.

INTRODUCTION: Flow cytometry is a useful tool for diagnosis and minimal residual disease (MRD) study of hematological diseases. Standard sample preparation protocols are characterized by stain-lyse-wash (SLW). To prevent nonspecific bindings and achieve high sensitivity in MRD studies, lyse-wash-stain-wash (LWSW) is required. To our knowledge, no comparison between the two methods has been performed. METHODS: We compared mean fluorescence intensity (MFI), stain index, signal-to-noise ratio, and percentage of positive cells of 104 antibodies and of 13 selected antibodies tested in 10 samples simultaneously prepared with the two methods. RESULTS: MFI and percentages of positive cells obtained by the two methods did not show significant differences and showed a very high correlation. Stain index and signal-to-noise ratio presented higher values for kappa and lambda surface chains in LWSW samples and a trend of higher values for the other antibodies in SLW samples. CONCLUSIONS: We suggest to use LWSW method also at diagnosis to obtain more comparable antibody intensity expressions when samples from the same patient are processed for MRD evaluation after bulk lysis. Moreover, LWSW can prevent nonspecific bindings, shows no differences in the identification and quantitation of the populations of interest, and reduces acquisition of cell debris.