Arsenic trioxide and low-dose cytarabine for patients with intermediate-2 and high-risk myelodysplastic syndrome.

Advanced myelodysplastic syndrome (MDS) carries a poor prognosis. In this phase I/II study, arsenic trioxide was combined with low-dose cytarabine in 49 previously untreated patients with intermediate-2 and high-risk MDS. Complete remission was achieved in 8 (17%) patients, including 3/14 (21%) with treatment-related disease, 4/31 (13%) with unfavorable cytogenetics and 2/36 (6%) with baseline poor performance status. Mortality within the first 4 weeks was 8%. The regimen was active and had a tolerable extramedullary toxicity profile, but it was cumbersome and intensive compared to other currently available treatments.

Suboptimal responses to imatinib in chronic myelogenous leukemia: what are they and how do they affect treatment?

First-line treatment for chronic myelogenous leukemia (CML) is imatinib, but some patients do not respond or develop resistance to the drug, leading to suboptimal responses. Dasatinib and nilotinib are approved second-line compounds for patients experiencing imatinib failure. In a prospective comparison of dasatinib with high-dose imatinib in patients who did not respond to first-line imatinib, dasatinib was more effective and well tolerated. Nilotinib also is effective, but cross-intolerance does occur in a substantial number of patients. This article explores the importance of suboptimal response to imatinib and the appropriate second-line therapy as well as nursing implications for caring for patients with CML.

Arsenic trioxide and low-dose cytarabine in older patients with untreated acute myeloid leukemia, excluding acute promyelocytic leukemia.

BACKGROUND: Acute myeloid leukemia (AML) carries a dismal prognosis in older patients. In this study, the authors evaluated the safety and efficacy of arsenic trioxide combined with low-dose cytarabine in untreated patients aged >or=60 years with AML. METHODS: In a phase 1/2 design, arsenic trioxide was administered intravenously at a dose of 0.25 mg/kg on Days 1 through 5 and on Days 8 through 12, and low-dose cytarabine was given subcutaneously twice daily on Days 1 through 14 in escalating doses to a target of 10 mg/m(2) per dose. Of 64 patients who had pathologically confirmed AML, excluding patients with acute promyelocytic leukemia and using World Health Organization criteria, the median age was 71 years, 10 patients (16%) had treatment-related AML, 40 patients (63%) had an antecedent myelodysplastic syndrome or myeloproliferative disorder, and 35 patients (55%) had unfavorable cytogenetics. Thirty-four patients (53%) had an Eastern Cooperative Oncology Group performance status of 2 or 3. RESULTS: Complete remission was achieved in 21 of 61 patients (34%), including 15 of 50 patients (30%) who had secondary or treatment-related AML, 10 of 33 patients (30%) who had unfavorable cytogenetics, and 6 of 34 patients (18%) who had a poor baseline performance status. The mortality rate within the first 4 weeks was 8%. Neutropenic fever was observed in >80% of patients, and 41% of patients had bacteremia. Nonhematologic toxicity generally was mild and reversible and included fatigue, nausea, diarrhea, rash, peripheral edema, and elevated transaminases. There were no clinically significant cardiac arrhythmias. CONCLUSIONS: The addition of arsenic trioxide to low-dose cytarabine appeared to improve responses in elderly patients who had AML compared with either agent alone, and a randomized trial of the combination versus single-agent low-dose cytarabine is ongoing.

Phase I/II study of continuous-infusion troxacitabine in refractory acute myeloid leukemia.

PURPOSE: Troxacitabine is a non-natural nucleoside analog with unique structural and metabolic features. Bolus intravenous (IV) troxacitabine regimens have shown significant activity in patients with refractory acute myeloid leukemia (AML) and preclinical data suggest that administration via continuous infusion may result in enhanced antitumor activity. PATIENTS AND METHODS: Patients with refractory AML initially received troxacitabine 10.1 mg/m2 by continuous IV infusion (CIVI) for 48 hours. Infusion duration and daily dose were increased in subsequent patient cohorts. RESULTS: Forty-eight patients, median age 58 years (range, 21 to 81 years), were treated. Dose-limiting toxicities were mucositis and hand-foot syndrome, and 12.0 mg/m2/d for 5 days was established as the maximum-tolerated dose. Seven patients (15%) achieved complete remission (CR) or CR with incomplete platelet recovery (CRp), with a median survival among responders of 12 months. Steady-state concentrations of troxacitabine were found to be linearly and inversely proportionally related to calculated creatinine clearance at doses of 10.1 and 12.0 mg/m2/d. All patients responding to troxacitabine had steady-state serum drug concentration of more than approximately 80 ng/mL. In 27 patients achieving target troxacitabine plasma concentrations (ie, approximately 80 ng/mL) the CR + CRp rate was 26%. CONCLUSION: Troxacitabine administered as a CIVI allows a significant increase in dose-intensity in comparison to IV bolus regimens, has antileukemic activity, and warrants additional investigation in patients with refractory AML. The recommended phase II study dose is 12.0 mg/m2 daily CIVI for 5 days.