Mitoxantrone and Etoposide for the Treatment of Acute Myeloid Leukemia Patients in First Relapse.

Relapsed acute myeloid leukemia (AML) represents a major therapeutic challenge. Achieving complete remission (CR) with salvage chemotherapy is the first goal of therapy for relapsed AML. However, there is no standard salvage chemotherapy. The current study evaluated outcomes and prognostic factors for achievement of CR in 91 AML patients in first relapse who were treated with the mitoxantrone-etoposide combination regimen. The overall response rate (CR and CRi) was 25%. Factors that were associated with a lower rate of CR included older age, shorter duration of first CR, low hemoglobin, and low platelet count. The median overall survival for all patients was 7.4 months. The survival of patients who achieved CR and underwent allogeneic hematopoietic cell transplantation (allo-HCT) was higher than those who achieved CR and did not undergo allo-HCT (35.3 months vs. 16.8 months, p = 0.057). The median duration of relapse-free survival was 12.7 months in the patients achieving CR. Older age at the time of AML relapse was associated with worse overall survival. The all-cause 4-week mortality rate was 4%, and the all-cause 8-week mortality rate was 13%. The findings of this study underscore the need for newer therapies, especially those that will improve the ability for patients with relapsed AML to achieve CR and to allow them to receive additional therapies.

Intensive chemotherapy in patients aged 70 years or older newly diagnosed with acute myeloid leukemia.

Acute myeloid leukemia (AML) represents a major therapeutic challenge in the elderly. Because of the high treatment-related mortality and poor overall outcomes of remission induction therapy, many older patients are not considered candidates for intensive chemotherapy. The current study evaluated prognostic factors for achievement of complete remission (CR) in newly diagnosed elderly AML patients who were treated with initial intensive chemotherapy. The study included 62 newly diagnosed AML patients ≥ 70 years who were treated with intensive chemotherapy. The overall response rate (CR and CRp) was 56%. Patients with favorable or intermediate cytogenetics (p=0.0036) as well as those with primary AML (p=0.0212) had a higher response rate. The median overall survival for all patients was 6.85 months (95% CI 3.7-13.5 months). The median overall survival for patients achieving remission after intensive induction chemotherapy was significantly higher than those who did not respond to therapy (20.4 months vs. 3.5 months, p<0.001). The all-cause 4-week mortality rate was 11%, and the all-cause 8-week mortality rate was 17.7%. A subgroup of elderly patients may benefit more from initial intensive induction chemotherapy, specifically those patients with performance status able to tolerate induction chemotherapy and favorable cytogenetic status. However, despite high rates of initial CR, relapse rates are still high, suggesting that alternative strategies of postremission therapy are warranted.

Fludarabine and cytarabine in patients with relapsed acute myeloid leukemia refractory to initial salvage therapy.

The most effective regimen for relapsed acute myeloid leukemia (AML) patients who do not achieve complete remission (CR) after a course of salvage therapy has not been established. We evaluated the efficacy and toxicity of fludarabine and cytarabine in patients with AML in first relapse who did not respond to a course of salvage chemotherapy with mitoxantrone and etoposide. CR was achieved in 39 % of treated patients, and in 47 % of patients with a favorable/intermediate-risk karyotype. The median overall survival was 4.75 months. The median survival for patients achieving CR with fludarabine-cytarabine was significantly higher than for those who did not respond to therapy (9.6 vs. 4.5 months, P = 0.04). Our data suggest that the fludarabine-cytarabine regimen merits further investigation in relapsed AML patients with favorable or intermediate-risk karyotype with persistent leukemia after a course of salvage therapy.

Fludarabine and cytarabine in patients with acute myeloid leukemia refractory to two different courses of front-line chemotherapy.

The most effective regimen for acute myeloid leukemia (AML) patients who do not achieve complete remission (CR) after two different courses of front-line chemotherapy has not been established. We therefore evaluated the efficacy, toxicity, and prognostic factors for achieving CR following treatment with fludarabine and cytarabine in 25 newly diagnosed AML patients who did not respond to initial therapy with idarubicin and cytarabine followed by mitoxantrone and etoposide. CR was achieved in 32% of patients; in 55% of patients with intermediate-risk karyotype and in 14% with unfavorable-risk. Eight percent died of infectious complications. Median duration of overall survival was 6.6 months (95% CI 3.4 months to ∞); 3.4 months (95% CI 0.8-8.6 months) for patients with an unfavorable-risk karyotype and 18.1 months (95% CI 5.0 months to ∞) with an intermediate-risk karyotype (p=0.02). Our data suggest that poor-risk karyotype patients are unlikely to benefit from third course treatment with fludarabine-cytarabine, and that this regimen merits further investigation in AML patients with good or intermediate-risk karyotype that have persistent leukemia after two courses of front-line chemotherapy.