Continuous infusion mitoxantrone in relapsed acute nonlymphocytic leukemia

Relapsed and refractory pediatric acute myeloid leukemia: current and emerging treatments

Survival rates for children with acute myeloid leukemia (AML) exceed 60 % when modern, intensified chemotherapeutic regimens and enhanced supportive care measures are employed. Despite well-recognized improvements in outcomes, primary refractory or relapsed pediatric AML yields significant morbidity and mortality, and improved understanding of this obstinate population along with refined treatment protocols are urgently needed. Although a significant number of patients with refractory or relapsed disease will achieve remission, long-term survival rates remain poor, and efforts to identify therapies which will improve OS are under continuous investigation. The current fundamental goal of such investigation is the achievement of as complete a remission as possible without dose-limiting toxicities, and the progression to hematopoietic stem cell transplantation thereafter. In this review the scope of the problem of relapsed and refractory AML as well as current and emerging chemotherapy options will be discussed.

A randomized trial of continuous infusion versus bolus mitoxantrone in combination with cytarabine in newly diagnosed patients with acute myeloblastic leukemia

Mitoxantrone (MTZ) has been shown to be effective in the treatment of newly diagnosed acute myeloblastic leukemia (AML). The objective of this randomized study was to evaluate the impact of mode of administration of MTZ on the response and recurrence rates in newly diagnosed patients with AML and to compare the toxicity patterns associated with bolus and continuous infusion (CI) of MTZ. From March 1987 to March 1994, 40 newly diagnosed patients with AML were randomized to receive either bolus or CI-MTZ, administered for 3 days at 10 mg/m2/day in combination with CI-cytarabine for 7 days at 100 mg/m2/day. Patients achieving complete remission (CR) received two consolidation cycles followed by monthly maintenance cycles, aiming a total of 12 cycles of chemotherapy. Fifteen patients (75%) in the bolus arm and 16 patients (80%) in the CI arm achieved CR. There were no significant differences in rates of early death and time to myeloid recovery between the two groups. After 11 years from the initiation of the study, median disease-free survival (DFS) in bolus and CI groups were 19 and 29 months after a median follow-up of 10 and 14 months, respectively. DFS rates at 10 years were 16.7% in the bolus group and 28.6% in the CI group (p = 0.36). Overall survival (OS) rates during the same period were 10.7 and 21.3% in the bolus and CI groups, respectively (p = 0.26). No relapse was observed in either group after 4 years. In patients younger than 40 years of age, DFS and OS were found to be significantly longer in the CI arm (p = 0.02 and p = 0.03, respectively). Mild asymptomatic cardiotoxicity associated with a decrease of 10 to 20% in the ejection fraction occurred in a patient in CI-MTZ arm and in two patients in the bolus arm. None of these patients showed any evidence of cardiac failure during their subsequent follow-up. Grade III-IV alopecia (p = 0.05) and grade I-II hepatotoxicity (p = 0.01) were more frequent in the CI arm. A tendency for higher frequency of grade III-IV nausea was observed in the bolus arm (9 vs. 3%, p = 0.10). As a conclusion, bolus and CI administration of MTZ were equally effective and tolerated well. Development of new anti-leukemia agents with novel treatment approaches is still needed to improve the high relapse rates in patients with AML who do not have an HLA-matched donor.

Continuous mitoxantrone infusion in pretreated epithelial ovarian cancer

Mitoxantrone has shown moderate activity in advanced epithelial ovarian cancer following intermittent i.v. administration. Experiments and clinical data suggest that long-term continuous drug infusion may achieve a better therapeutic result with less toxicity. This hypothesis was tested in patients with advanced ovarian cancer who had been pretreated with other agents. Mitoxantrone was infused continuously in 21-day courses beginning every 6 weeks. If severe toxicity did not occur, the infusion rate was increased by 0.1-0.2 mg/m2 per day. The mitoxantrone solution proved to be stable over the 21-day infusion period. For ethical reasons an optimal two-stage design was employed. The trial was interrupted at the end of the first recruitment stage because the target of 3 responses out of 13 patients had not been achieved (only 1 patient had a partial response). Hematologic toxicity was observed in 11 patients, and 2 of them had a catheter occlusion. In conclusion, we found that 21-day of infusion of mitoxantrone apparently has no clinical benefit as compared with bolus administration in patients with advanced ovarian cancer.

Anthracycline-based therapy of de novo acute myeloid leukemia in adults: failure of first-cycle cytoreduction to predict second-cycle outcome

During 1971-1988, 194 adults with de novo acute myeloid leukemia (AML) received initial therapy at the University of Minnesota with an anthracycline-based regimen. Seventy-two of the 194 required further chemotherapy and received a second cycle of the same or similar therapy; 63 of these 72 were evaluable. For each marrow, a tumor burden index (TBI) was calculated, as the product of the marrow cellularity and the proportion of malignant cells. For each patient, the decrement in TBI between the initial and day approximately 14 marrows was recorded. Patients who achieved second-cycle CR were comparable to those who did not in general descriptors; there was no difference between second-cycle CR achievers and nonachievers in the cytoreduction effected by the initial cycle of therapy (74.9% +/- 4.5% [sigma] versus 71.9% +/- 5.9%). We then stratified patients according to the first-cycle cytoreduction, asking if we could find a level that was reliably predictive of increased or decreased likelihood of achieving CR with cycle 2. We could not, despite testing at many centile cuts. Patients achieving a very "poor" degree of cytoreduction in cycle 1 were as likely to achieve CR with cycle 2 as were patients having a very "good" initial cytoreduction. We conclude that (1) first-cycle response is not a useful predictor of second-cycle outcome in anthracycline-based therapy of de novo adult AML; and (2) a "poor" response to cycle 1 does not therefore a priori indicate a change to a different regimen for cycle 2.

Mitoxantrone. A review of its pharmacodynamic and pharmacokinetic properties, and therapeutic potential in the chemotherapy of cancer

Mitoxantrone is a dihydroxyanthracenedione derivative which as intravenous mono- and combination therapy has demonstrated therapeutic efficacy similar to that of standard induction and salvage treatment regimens in advanced breast cancer, non-Hodgkin's lymphoma, acute nonlymphoblastic leukaemia and chronic myelogenous leukaemia in blast crisis; it appears to be an effective alternative to the anthracycline component of standard treatment regimens in these indications. Mitoxantrone is also effective as a component of predominantly palliative treatment regimens for hepatic and advanced ovarian carcinoma. Limited studies suggest useful therapeutic activity in multiple myeloma and acute lymphoblastic leukaemia. Regional therapy of malignant effusions, hepatic and ovarian carcinomas has also been very effective, with a reduction in systemic adverse effects. Mitoxantrone inhibits DNA synthesis by intercalating DNA, inducing DNA strand breaks, and causing DNA aggregation and compaction, and delays cell cycle progression, particularly in late S phase. In vitro antitumour activity is concentration- and exposure time-proportional, and synergy with other antineoplastic drugs has been demonstrated in murine tumour models. Leucopenia may be dose-limiting in patients with solid tumours, whereas stomatitis may be dose-limiting in patients with leukaemia. Other adverse effects are usually of mild or moderate severity although cardiac effects, particularly congestive heart failure, may be of concern, especially in patients with a history of anthracycline therapy, mediastinal irradiation or cardiovascular disease. Mitoxantrone displays an improved tolerability profile compared with doxorubicin and other anthracyclines, although myelosuppression may occur more frequently. Thus, mitoxantrone is an effective and better tolerated alternative to the anthracyclines in most haematological malignancies, in breast cancer and in advanced hepatic or ovarian carcinoma. Further studies may consolidate its role in the treatment of these and other malignancies.