Advances in chemotherapy and supportive cares have significantly improved the results of treatment of patients with acute myelogenous leukemia(AML). Although the
60% to 85% of patients achieved complete remission(CR), most of them have eventually experienced relapse within 1 year after CR. Also it seems to be accepted that relapsed
leukemic blasts became more resistant to first-line chemotherapeutic including cytosine arabinoside(Ara-C) and anthracyclines. To overcome this clinical dilemma it requires the development of new and effective chemotherapeutic regimens that are non-cross resistant with available drugs. 4'- (9-acridinylamino) methanesulfon-m-anisidide(AMSA), which has been to be an inhibitor of DNA synthesis by intercalation with DNA molecule, have potential antitumor activity.
Twenty seven patients with refractory or relapsed AML were treated with AMSA containing regimens for remission reinduction. Eight patients (50%) achieved CR in
refractory AML and seven (65%) in relapsed AML. Overall CR rate was 56% (15/27). Median duration of CR was 5 months(2-28＋). CR rate achieved below 30 years old was 40% (6/15) and above 30 years old 75% (9/15). There was no correlation between median duration of previous remission(6 month>vs<) and second CR(63% vs 67%). One patient died of ventricular fibrillation during the recovery of pancytopenia. Major toxicity and side effects were infection 18/27(67%), mucositis 7/27(26%), nausa and vomiting 6/27(22%) and diarrhea 5/27 (19%). But these could be circumvented by appropriate supportive cares.
Our results suggest that AMSA should have significant antileukemic activity against refractory or relapsed AML and deserve further evaluation for late intensification to the patients with AML.

Keywords: AMSA, Chemotherapy, Relapsed or Refractory Acute Myelogenous Leukemia,