ALL R-87 protocol in the treatment of children with acute lymphoblastic leukaemia in early bone marrow relapse

Seventy-three children with acute lymphoblastic leukaemia (ALL) in first bone marrow (BM) relapse, occurring within 30 months from complete remission (CR) were enrolled in an Italian cooperative study (ALL R-87 protocol). This treatment programme consisted of an induction phase with intermediate-dose cytarabine (IDARA-C) plus idarubicin (IDA) and prednisone (PDN), followed by a multidrug consolidation therapy and bone marrow transplant (BMT). 55/73 children achieved CR (75.3%); 15 (20.5%) failed to respond and three (4.2%) died during induction. The response rate was significantly higher for children with a first CR duration greater than or equal to 12 months (P = 0.0005) and for those with a white blood cell (WBC) count at relapse <20x10(9)/l (P=0.004). The estimated disease-free survival (DFS +/- SE) at 82 months was 0.18 +/- 0.05 for all responders, and 0.70 +/- 0.14 for allotransplanted patients versus 0.05 +/- 0.05 for those autografted (P=0.001). The estimated probabilities of survival +/- SE and event-fi ee survival (EFS +/- SE) at 83 months were 0.16 +/- 0.07 and 0.13 +/- 0.04, respectively, for all enrolled children. Univariate analysis showed that age <10 pears at initial diagnosis and B-lineage immunophenotype Favourably influenced both DFS (P=0.001) and EFS probabilities (P=0.0014 and P=0.012, respectively), whereas a first CR duration greater than or equal to 12 months and a WBC count at relapse <20x10(9)/l were associated only with a better EFS rate (P = 0.026 and P = 0.004, respectively). Our results show the efficacy of the IDA plus IDARA-C schedule used in the ALL R-87 protocol in high-risk relapsed ALL children. Allogeneic BMT proved effective for patients with an HLA sibling donor. In a multivariate analysis, age greater than or equal to 10 years at initial diagnosis (P=0.016) and WBC count at relapse greater than or equal to 20x10(9)/l (P=0.048) were independently associated with a worse disease outcome.