Purpose: To confirm and extend encouraging preliminary results of timed sequential chemotherapy (TSC) in patients with previously treated acute myelogenous leukemia (AML).
Patients and methods: We report the results of the regimen of mitoxantrone on days 1 to 3, etoposide on days 8 to 10, and cytarabine on days 1 to 3 and 8 to 10 (EMA) in 133 patients, with a median follow-up of 40 months.
Results: Sixty percent of patients, with a 95% confidence interval (CI) ranging from 51% to 68%, achieved complete remission (CR), including 44% (CI, 32% to 57%) of refractory patients and 76% (CI, 64% to 86%) of late first-relapse patients (P = .0002). Twenty-nine percent of patients did not respond to therapy, and 11% died from toxicity. Median duration of neutropenia and thrombocytopenia was 31 days and 29 days, respectively. Severe nonhematologic toxicity included sepsis in 54% of patients and mucositis in 23%. Postinduction therapy included a second course of EMA in 27 patients, maintenance in 10, autologous bone marrow transplantation (BMT) in 12, and allogeneic BMT in 13. Median survival of patients who did not have transplantation performed is 7 months, with 11% (CI, 4% to 18%) survival at 5 years. Median disease-free survival (DFS) is 8 months with 20% (CI, 8% to 32%) DFS at 5 years. Twenty-eight percent (CI, 15% to 44%) of nontransplanted patients who achieved CR had an inversion of CR duration. Previous refractoriness was the main factor associated with poor prognosis for CR achievement, DFS, and survival.
Conclusion: These results confirm initial reports on TSC and show that approximately 20% of patients with first relapse after therapy can enjoy prolonged DFS using chemotherapy only.