Treatment Outcome with Imatinib-Based Maintenance Therapy in Elderly Patients with Philadelphia-Positive Acute Lymphoblastic Leukaemia (ph+all) Ineligible for Allogeneic Stem Cell Transplantation (SCT).

Background: The tyrosine kinase inhibitor imatinib (IM), alone or in combination with induction and post-remission chemotherapy, has become the mainstay of front-line treatment for Ph+ ALL, followed by allogeneic SCT as a potentially curative treatment option. However, alloSCT is not feasible in many elderly or comorbid patients. In a prospective, randomized clinical trial of elderly patients with de novo Ph+ ALL, we recently demonstrated that IM induction followed by IM in combination with intensive consolidation chemotherapy of approximately one year duration was feasible in the majority of pts. but associated with a high relapse rate. To assess the impact of IM-based maintenance, we here provide an analysis of maintenance therapy with IM either alone, in combination with low dose interferon-α (LD-IFNα), or with zoledronic acid. In addition, we examined whether determination of minimal residual disease (MRD) and/or BCR-ABL mutation status prior to and during pre-maintenance therapy were predictive of freedom from relapse and remission duration.