Acute promyelocytic leukemia: a 5-year experience with new antileukemic agents and a new approach to preventing fatal hemorrhage.

Forty-six induction courses were administered to 32 patients with acute promyelocytic leukemia. There were 28 males and 18 females with a median age of 39.5 (range 19-68). Twelve patients were previously untreated, 32 were in relapse, and 2 were refractory to primary induction chemotherapy. Heparin 7.5-10 units/kg/h by continuous infusion, 4-6 units of platelets and 1-2 units of fresh-frozen plasma (FFP) every 12 h were given to all patients. Previously untreated patients received either daunorubicin, idarubicin or mitoxantrone in combination with cytarabine (Ara-C). For relapsed and refractory patients, regimens included amsacrine with high-dose cytarabine (Amsa/HiDac), homoharringtonine (HHT) alone, or with Ara-C, mitoxantrone and bisantrene. Hemorrhagic complications occurred in only 1 out of 46 courses (2%). Complete remission rates (CR) were as follows: previously untreated 83% (10/12), relapsed 66% (21/32), primary refractory 50% (1/2). Amsa/HiDac resulted in a 71% (10/14) CR and HHT-based regimens achieved a 46% (6/13) CR. These regimens are effective and the value of their incorporation into primary therapy should be studied. The use of heparin with platelet and FFP transfusions every 12 h reduces the risk of hemorrhage during induction therapy.