Effective reinduction therapy for childhood acute nonlymphoid leukemia using simultaneous continuous infusions of teniposide and amsacrine

The combination of teniposide (VM-26) and amsacrine (AMSA) was evaluated in a dose-finding and efficacy study in 58 patients with relapsed or refractory acute leukemia. Both agents were given as simultaneous continuous infusions for 72 h through separate i.v. lines. All patients were evaluable for toxicity and 57 were evaluable for response; only 2 of 20 with acute lymphoblastic leukemia (ALL), acute mixed-lineage leukemia, or chronic myelogenous leukemia in blast crisis achieved a complete remission (CR). More encouraging was a second-remission rate of 43% (13 complete and 3 partial) in the 37 patients with acute nonlymphoid leukemia (ANLL). Responses occurred only in patients who received VM-26 doses of ≥200 mg/m2 per day and AMSA doses of≥100 mg/m2 per day. Thus, the CR rate for relapsed ANLL patients who received the higher doses of both agents was 40% (13 of 33). All responders had previously received epipodophyllotoxin therapy and 40% had also received AMSA. All but one patient had severe leukopenia (<2.0x109 leukocytes/l) and thrombocytopenia (<50.0x109 platelets/l) as a result of therapy. Severe mucositis (grade 3 or 4) was the dose-limiting toxicity. Our results indicate that VM-26 plus AMSA, given by continuous infusion, is effective in the treatment of ANLL. Further phase II studies should consider using VM-26 at 200 mg/m2 per day and AMSA at 100 mg/m2 per day, but the best administration schedule remains unclear.