The relapsed AML 2001/01, 02 study for children with relapsed acute myeloid leukaemia or initially resistant disease has improved outcome
Abstract
Relapse of acute myeloid leukaemia (AML) or AML initially resistant to treatment is extremely prognostically unfavourable. Between VIII/2001 and III/2009 in the Czech Republic, twenty patients aged 0-18 years with this diagnosis were treated as part of the international Relapsed AML 2001/01study.
The protocol consisted of two blocks of chemotherapy based on a high-dose cytosine-arabinoside in combination with fludarabine. In the first block, patients were randomized to receive liposomal daunorubicin (DaunoXome).
If there was > 20% blasts in the bone marrow after the first block or if a complete remission was not achieved after the second block, patients were considered non-responders and were excluded from the study. They were however eligible for the therapeutic study Relapsed AML 2001/02 with gemtuzumab ozogamicin (Mylotarg; GO) in monotherapy.
After achieving a 2nd remission, children were indicated to undergo hematopoietic stem cell transplantation (HSCT). Two patients were treated for an initially resistant disease, 18 children for the 1st relapse of AML.
In 61%, the relapse occurred early, less than 12 months from diagnosis. Six children did not respond to treatment, two died of an early death, twelve (60%) patients achieved a 2nd remission and 11 of these underwent allogeneic HSCT.
In total, 6 (30%) of the children are alive with a median follow up of 5.8 years, all having undergone allogeneic transplantation (2 children after the 2nd HSCT). For the whole group, the event free survival probability (EFS) at 5 years is 18 +- 9%, the overall survival (OS) probability is 34 +- 11%.
Treatment in the Relapsed AML 2001 study improved the prognosis of children with relapsed AML in the Czech Republic compared to the previous period 1993-2001 (n=22 children, OS 14%).