Improved remission induction rate with D-ZAPO but unimproved remission duration with addition of immunotherapy to chemotherapy in previously untreated children with ANLL

In 163 children with acute nonlymphocytic leukemia (ANLL), a D-ZAPO induction program consisting of daunomycin, 5-azacytidine, cytosine arabinoside, prednisone, and vincristine resulted in a remission rate of 71.8%. Immunologic therapy was employed during maintenance with the aim of prolonging remission and improving survival. The administration of immunotherapy consisting of a mixture of bacillus Calmette-Guérin (BCG) and allogeneic acute myelomonocytic leukemic cells injected intradermally on day 14 of each of the first three monthly cycles of 6-thioguanine for ten days, 5-azacytidine and cytosine arabinoside for four days, and vincristine for one day did not improve remission duration or survival compared to that due to chemotherapy alone. Important prognostic factors identified in this study included a remission induction rate significantly better for females than males (P = 0.04), for children between the ages of 5 and 10 years compared to those greater than this age group (P = 0.01), and a prolonged remission duration (P = 0.04), and survival (P < 0.01) for patients with initial white blood counts of <20 × 10⁹/liter.