A phase 1b/2 study of vosaroxin in combination with cytarabine in patients with relapsed or refractory acute myeloid leukemia.

Vosaroxin is a first-in-class anticancer quinolone derivative that intercalates DNA and inhibits topoisomerase II. This study assessed the safety and tolerability of vosaroxin plus cytarabine in patients with relapsed/refractory acute myeloid leukemia. Escalating vosaroxin doses (10-minute infusion; 10-90 mg/m(2); days 1, 4) were given in combination with cytarabine on one of two schedules: schedule A (24-hour continuous intravenous infusion, 400 mg/m(2)/day, days 1-5) or schedule B (2-hour intravenous infusion, 1 g/m(2)/day, days 1-5). Following dose escalation, enrollment was expanded at the maximum tolerated dose. Of 110 patients enrolled, 108 received treatment. The maximum tolerated dose of vosaroxin was 80 mg/m(2) for schedule A (dose-limiting toxicities: grade 3 bowel obstruction and stomatitis) and was not reached for schedule B (recommended phase 2 dose: 90 mg/m(2)). In the efficacy population (all patients in first relapse or with primary refractory disease treated with vosaroxin 80-90 mg/m(2); n=69), the complete remission rate was 25% and the complete remission/complete remission with incomplete blood count recovery rate was 28%. The 30-day all-cause mortality rate was 2.5% among all patients treated at a dose of 80-90 mg/m(2). Based upon these results, a phase 3 trial of vosaroxin plus cytarabine was initiated in patients with relapsed/refractory acute myeloid leukemia. (Clinicaltrials.gov identifier: NCT00541866).

REVEAL-1, a phase 2 dose regimen optimization study of vosaroxin in older poor-risk patients with previously untreated acute myeloid leukaemia.

This phase 2 study (N = 116) evaluated single-agent vosaroxin, a first-in-class anticancer quinolone derivative, in patients ≥60 years of age with previously untreated unfavourable prognosis acute myeloid leukaemia. Dose regimen optimization was explored in sequential cohorts (A: 72 mg/m(2)  d 1, 8, 15; B: 72 mg/m(2)  d 1, 8; C: 72 mg/m(2) or 90 mg/m(2)  d 1, 4). The primary endpoint was combined complete remission rate (complete remission [CR] plus CR with incomplete platelet recovery [CRp]). Common (>20%) grade ≥3 adverse events were thrombocytopenia, febrile neutropenia, anaemia, neutropenia, sepsis, pneumonia, stomatitis and hypokalaemia. Overall CR and CR/CRp rates were 29% and 32%; median overall survival (OS) was 7·0 months; 1-year OS was 34%. Schedule C (72 mg/m(2) ) had the most favourable safety and efficacy profile, with faster haematological recovery (median 27 d) and lowest incidence of aggregate sepsis (24%) and 30-d (7%) and 60-d (17%) all-cause mortality; at this dose and schedule, CR and CR/CRp rates were 31% and 35%, median OS was 7·7 months and 1-year OS was 38%. Overall, vosaroxin resulted in low early mortality and an encouraging response rate; vosaroxin 72 mg/m(2)  d 1, 4 is recommended for further study in this population. Registered at www.clinicaltrials.gov: #NCT00607997.

Phase II multicenter trial of voreloxin as second-line therapy in chemotherapy-sensitive or refractory small cell lung cancer.

INTRODUCTION: Voreloxin is an anticancer quinolone derivative that intercalates DNA and inhibits topoisomerase II, causing double-strand breaks in DNA, irreversible G2 arrest, and rapid onset of apoptosis. Based on preclinical activity of voreloxin in chemoresistant tumors, early phase I clinical activity, and a mechanism of action similar to other topoisomerase II inhibitors such as the anthracyclines and etoposide, this phase II trial was undertaken as second-line treatment of small cell lung cancer (SCLC). METHODS: Patients with extensive stage SCLC previously treated with one prior chemotherapy regimen were eligible. Patients with chemotherapy-sensitive or chemotherapy-refractory disease were considered as separate cohorts. Voreloxin (48 mg/m) was administered on the first day of each 21-day cycle for up to six cycles. The primary end point was objective response rate. RESULTS: Fifty-five patients were enrolled including 28 with refractory SCLC and 27 with sensitive SCLC; 47 were evaluable for response. Three patients with sensitive SCLC had an objective response, including one complete response and two partial responses (11% response rate based on intent to treat). No patients in the refractory cohort had a response. The primary grade 3 toxicity was neutropenia. CONCLUSION: Voreloxin has minimal activity in relapsed SCLC when administered at 48 mg/m in a 3-week schedule.