Good prognosis of patients with acute promyelocytic leukemia who achieved second complete remission (CR) with a new retinoid, AM80, after relapse from CR induced by all-trans-retinoic acid

A new synthetic retinoid, Am80, is effective in treating acute promyelocyti c leukemia relapsed from all-trans-retinoic acid-induced complete remission (CR). We report hers the long-term clinical outcomes of patients who achie ved second CR with Am80. Of 24 evaluable patients. 14 achieved a second CR by Am80 therapy. Of those patients, 4 relapsed within 6 months, despite sub sequent consolidation chemotherapy. Six patients underwent sibling or unrel ated HLA-matched allogeneic bone marrow transplantation (BMT): and 4 are al ive without relapse for more than 49 months after achieving second CR. Four of 8 patients who did not receive BMT are alive without relapse for mon th an 49 months. Promyelocytic leukemia-retinoic acid receptor alpha (PML-RAR alpha) fusion transcript was undetectable by reverse transcriptase-polymera se chain reaction in all living patients. Therefore, if patients achieve se cond CR with Am80 and HLA-matched donors are available, BMT is the treatmen t of choice. However, it is noteworthy that CR was maintained for more than 49 months in half of the patients who did not receive BMT. Int J Hematol. 2000;72:470-373. (C)2000 The Japanese Society of Hematology.