Results of the PETHEMA ALL-96 trial in elderly patients with Philadelphia chromosome-negative acute lymphoblastic leukemia.

BACKGROUND AND AIM: Only 20-30% of elderly patients with acute lymphoblastic leukemia (ALL) are enrolled in clinical trials because of co-morbid disorders or poor performance status. We present the results of treatment of Philadelphia chromosome-negative (Ph-) ALL patients over 55 yr treated in the PETHEMA ALL-96 trial.

PATIENTS AND METHODS: From 1996 to 2006, 33 patients > or = 55 yr with Ph- ALL were included. Induction therapy was vincristine, daunorubicin, prednisone, asparaginase, and cyclophosphamide over 5 weeks. Central nervous system (CNS) prophylaxis involved triple intrathecal (IT) therapy, 14 doses over the first year. Consolidation-1 included mercaptopurine, methotrexate, teniposide and cytarabine, followed by one consolidation-2 cycle similar to the induction cycle. Maintenance consisted of mercaptopurine and methotrexate up to 2 yr in complete remission (CR) with monthly reinduction cycles (vincristine, prednisone and asparaginase) during the first year.

RESULTS: Median (range) age was 65 yr (56-77). Phenotype (30 patients): early-pre-B 7, common/pre-B 18, T 5. Cytogenetics (28 patients): normal 12, complex 10, t(4;11) 2 and other 4. CR was achieved in 19/33 (57.6%) patients, early death occurred in 12 (36.4%) and 2 (6%) were resistant. Overall survival and disease-free survival probabilities (2 yr, 95% CI) were 39% (21%-57%) and 46% (22%-70%), respectively (median follow up of 24 months). Removal of asparaginase and cyclophosphamide from the induction decreased induction death (OR 0.119, CI 95% 0.022-0.637, P = 0.013) and increased survival (20% vs. 52%, P = 0.05).

CONCLUSIONS: The prognosis of elderly Ph- ALL patients is poor. In this study, less intensive induction decreased toxic death, allowing delivery of planned consolidation therapy and increased survival probability.