International Study for Treatment of High Risk Childhood Relapsed ALL 2010

Though survival of children with acute lymphoblastic leukemia (ALL) has considerably improved over the past few decades, relapsed ALL remains a leading cause of mortality in children with cancer. Risk has been defined by the International (I) Berlin, Frankfurt, Münster (BFM) Study Group (SG) based on duration of first remission, immunophenotype of malignant clone, and site of relapse. Patients classified as high risk (HR) by these criteria have poor response rates to standard induction therapy, high rates of subsequent relapse and require an allogeneic hematopoetic stem cell transplantation (allo-HSCT) for consolidation of 2nd remission. Over the last decade members of the I-BFM-SG have investigated the use of different combinations of conventional cytotoxic agents. Even with allo-HSCT, none of these approaches have improved outcome above 40%. Therefore, for HR patients there is a need to investigate the curative potential of new agents combined with systemic therapy. The proteasome inhibitor bortezomib has shown synergistic activity with acceptable toxicity when combined with corticosteroids, anthracyclines and alkylating agents in adult patients with cancer as well as with dexamethasone, doxorubicin, vincristine and polyethylene glycol (PEG) asparaginase in children with refractory or relapsed ALL. In the I-BFM-SG International Study for Treatment of High Risk Childhood Relapsed ALL (IntReALL) HR 2010 study, the potential of Bortezomib combined with a modified ALL relapse protocol 3 (R3) backbone as induction regimen for HR patients to improve complete 2nd remission (CR2) rates will be investigated in a randomized phase II design. Induction is followed by conventional intensive consolidation. After termination of the trial patients may be subjected to an investigational window, before all of them receive allo-HSCT.