High Remission Rates and Long-Term Survival in a High Percentage of Patients Achieved by Intensive Chemotherapy for AML and Further Improvement of Supportive Care.
Authors: Kyo Taiichi , Kimura Akiko , Kyo Kouhei , Yoshida Noriaki , Asaoku Hideki , Iwato Koji , Katayama Yuuta , Yuasa Hiromi 
Published: October 2019

Abstract
Abstract 1052
Poster Board I-74

Background:
Until recently, intensive chemotherapy for acute myeloid leukemia (AML) did not necessarily lead to high success rates, partly because of deaths from infections due to the associated long-term neutropenic phase. However, the advent of effective antifungal agents or the use of granulocyte colony-stimulating factor (G-CSF) or macrophage colony-stimulating factor (M-CSF) has definitely reduced deaths from chemotherapy and has improved the results of treatment with intensive chemotherapy also in elderly patients.

Objectives:
The complete remission rate after remission induction therapy and the event-free survival (EFS) after postremission therapy were investigated in 165 patients (99 men and 66 women) with untreated de novo AML (excluding subtype M3) who were consecutively registered in a single institution between March 2001 and March 2009. The patients' ages ranged from 16 to 94 years (median: 59 years). There were 3 patients with M0, 18 patients with M1, 25 patients with M2, 25 patients with t(8;21), 35 patients with M4, 12 patients with M4Eo, 35 patients with M5, 10 patients with M6, and 2 patients with M7.

Methods:
Remission induction therapy consisted of 10 days of behenoyl-ara-C (BHAC) at 350 mg/m2 (300 mg/m2 for patients 70 years or older) and 4 days of idarubicin (IDA) at 12 mg/m2 (10 mg/m2 for 70 years or older). Further, if bone marrow examination revealed 5% or more residual blast cells on day 15, etoposide was additionally administered at a dose of 100 mg/m2 for 4 days. The efficacy of the remission induction therapy was evaluated after 1 course of treatment. The patients who had achieved remission underwent 9 courses of postremission therapy, which lasted 11 months. The details are omitted, but therapy with high-dose (2 g/m2 [1 g/m2 for patients 60 years or older]) cytarabine (HDAC)×10 plus 7 mg/m2 of mitoxantrone (MIT) ×3 was performed during the 1st and 9th courses. No HDAC was performed on the elderly aged above 75 years old. The intensive therapy with Aclarubicin (ACR) of 20 mg/body for 14 days and the maintenance therapy with a combination of BHAC 350 mg/m2×4 with ACR or IDA were repeated alternately every 6 weeks. Chemotherapies other than remission induction therapy and HDAC were performed in an outpatient clinic, and if the patients with the WBC decreasing to 1000/mm3 were hospitalized in the biological clean room. M-CS was administered for 7 days after the day following the end of chemotherapy, and subsequently G-CSF was administered until the WBC becomes to be 1000/mm3.

Results:
Complete remission (CR) was achieved in 143 of the 165 patients overall (86.7%), 113 of the 123 patients 69 years or younger (92.7%), and 29 of the 42 patients 70 years or older (69.1%). During the remission induction therapy, death occurred in 6 of the 165 patients overall (3.6%), 2 of the 123 patients 69 years or younger (1.6%), and 4 of the 42 patients 70 years or older (9.5%). The EFS in patients with CR was 61.5% at 8 years in patients 69 years or younger, while it was 26.9% at 5 years in patients 70 years or older. There was only a case of death due to chemotherapy during postremission therapy. Seven patients underwent bone marrow transplantation during the first remission, and 6 of these patients have been enjoying EFS.

Conclusion:
Improvement in supportive care has enabled safe intensive chemotherapy. The patients with good or intermediate prognosis were clearly improved by the present preliminary treatment at a single institution, but the patients with poor prognosis still highly require bone marrow transplantation in the future.

Disclosures:
No relevant conflicts of interest to declare.