Treatment of newly diagnosed acute promyelocytic leukemia (APL): a comparison of French-Belgian-Swiss and PETHEMA results.

All-trans retinoic acid (ATRA) plus anthracycline chemotherapy is the reference treatment of newly diagnosed acute promyelocytic leukemia (APL), whereas the role of cytosine arabinoside (AraC) remains disputed. We performed a joint analysis of patients younger than 65 years included in Programa para el Estudio de la Terapéutica en Hemopatía Maligna (PETHEMA) LPA 99 trial, where patients received no AraC in addition to ATRA, high cumulative dose idarubicin, and mitoxantrone, and APL 2000 trial, where patients received AraC in addition to ATRA and lower cumulative dose daunorubicin. In patients with white blood cell (WBC) count less than 10 x 10(9)/L, complete remission (CR) rates were similar, but 3-year cumulative incidence of relapse (CIR) was significantly lower in LPA 99 trial: 4.2% versus 14.3% (P = .03), although 3-year survival was similar in both trials. This suggested that AraC is not required in APL with WBC count less than 10 x 10(9)/L, at least in trials with high-dose anthracycline and maintenance treatment. In patients with WBC of 10 x 10(9)/L or more, however, the CR rate (95.1% vs 83.6% P = .018) and 3-year survival (91.5% vs 80.8%, P = .026) were significantly higher in APL 2000 trial, and there was a trend for lower 3-year CIR (9.9% vs 18.5%, P = .12), suggesting a beneficial role for AraC in those patients.

Phase II trial of arsenic trioxide and alpha interferon in patients with relapsed/refractory adult T-cell leukemia/lymphoma.

Human T-cell lymphotropic virus type 1 associated adult T-cell leukemia/lymphoma carries a very poor prognosis due to its intrinsic resistance to chemotherapy. Although zidovudine (AZT) and alpha-interferon (IFN) yield some responses and improve ATL prognosis, alternative therapies are needed. Arsenic trioxide (As) dramatically synergizes with IFN to induce growth arrest and apoptosis of ATL leukemia cells in vitro. These results prompted us to initiate a phase II trial of As/IFN combination in seven patients with relapsed/refractory ATL (four acute and three lymphoma). Four patients exhibited a clear initial response (one complete remission and three partial remissions). Yet, the treatment was discontinued after a median of 22 days because of toxicity (three patients) or subsequent progression (four patients). Six patients eventually died from progressive disease (five patients) or infection (one patient), but the remaining patient is still alive and disease free at 32 months. Pharmacokinetic studies showed that maximum arsenic blood levels (median 0.46 microM) were slowly achieved (8-15 days). In conclusion, arsenic/IFN treatment is feasible and exhibits an anti-leukemia effect in very poor prognosis ATL patients despite a significant toxicity. Future studies should assess the best timing for arsenic therapy: frontline with IFN/AZT or as maintenance after induction.