A phase 1 clinical-laboratory study of clofarabine followed by cyclophosphamide for adults with refractory acute leukemias

Clofarabine has shown impressive response rates in patients with acute leukemias. In vitro investigations with clofarabine in combination with cyclophosphamide in primary cells have demonstrated synergistic cytotoxicity and inhibition of DNA repair. Based on these clinical and laboratory observations, we designed a mechanism-based combination protocol with clofarabine and cyclophosphamide for patients with relapsed acute leukemias. Eighteen patients were treated with cyclophosphamide (200 mg/m2) alone on day 0 and with clofarabine plus cyclophosphamide on day 1. Clinical responses, toxicity, DNA damage measured as H2AX phosphorylation, and accumulation of clofarabine triphosphate (TP) were analyzed. At dose level 1 (20 mg/m2 clofarabine + cyclophosphamide, 6 patients) and dose level 0 (10 mg/m2 clofarabine + cyclophosphamide, 12 patients) overall response rates were 50% and 30%, respectively, with responses in 4 (67%) of 6 patients with refractory acute lymphoblastic leukemia. Dose-limiting toxicity occurred at dose level 1 with prolonged marrow aplasia. Four (22%) patients died from prolonged aplasia (1), fungal pneumonia (1), or multiorgan failure (2). In 12 of 13 patient samples, increased DNA damage (γH2AX) was observed with clofarabine and cyclophosphamide compared with cyclophosphamide alone. In conclusion, pharmacodynamic end points along with clinical results suggest usefulness of this combination strategy, whereas toxicity data suggest reduction in chemotherapeutic intensity. This clinical trial is registered with the National Cancer Institute's PDQ at www.clinicaltrials.gov as no. JHOC-J0561

Once-per-week selinexor, bortezomib, and dexamethasone versus twice-per-week bortezomib and dexamethasone in patients with multiple myeloma (BOSTON): a randomised, open-label, phase 3 trial

This is an accepted manuscript of an article published by Elsevier in The Lancet. The accepted version of the publication may differ from the final published version.Background Selinexor with dexamethasone has demonstrated activity in patients with heavily pretreated multiple myeloma (MM). In a phase 1b/2 study, the combination of oral selinexor with the proteasome inhibitor (PI) bortezomib, and dexamethasone (SVd) induced high response rates with low rates of peripheral neuropathy, the main dose-limiting toxicity of bortezomib. The aim of this trial was to evaluate the clinical benefit of weekly SVd versus standard bortezomib and dexamethasone (Vd) in patients with previously treated MM. Methods This phase 3, randomised, open label trial was conducted at 123 sites in 21 countries. Patients who were previously treated with one to three lines of therapy, including PIs were randomised (1:1) to selinexor (100 mg once-weekly) plus bortezomib (1·3 mg/m2 once-weekly) and dexamethasone (20 mg twice-weekly) [SVd] or bortezomib (1·3 mg/m2 twice-weekly) and dexamethasone (20 mg 4 times per week) [Vd]. Randomisation was done using interactive response technology and stratified by previous PI therapy, lines of treatment, and MM stage. The primary endpoint was progression-free survival (PFS) in the intention-to-treat population. Patients who received at least one dose of study treatment were included in the safety population. This trial is registered at ClinicalTrials.gov, NCT03110562. Findings Between June 2017 and February 2019, 402 patients were randomised: 195 to SVd and 207 to Vd. Median PFS was 13·93 (95% CI 11·73–NE) with SVd versus 9·46 months (8·11–10·78) with Vd; HR 0·70, [95% CI 0·53–0·93]; P=0.0075. Most frequent grade ≥3 adverse events (SVd vs Vd) were thrombocytopenia (77 [40%] vs 35 [17%]), fatigue (26 [13%] vs 2 [1%]), anaemia (31 [16%] vs 20 [10%]), and pneumonia (22 [11%] vs 22 [11%]). Peripheral neuropathy rates (overall, 32·3% vs 47·1%; OR 0·52, [95% CI 0·35-0·79]; P=0.0010 and grade ≥2, 21·0% vs 34·3%; OR 0·50, [95% CI 0·32-0·79]; P=0.0013) were lower with SVd. There were 47 (24%) deaths on SVd and 62 (30%) on Vd. Interpretation Once-weekly SVd is a novel, effective, and convenient treatment option for patients with MM who have received 1-3 prior therapies.Karyopharm Therapeutics Inc