Adult Acute Lymphoblastic Leukemia Treatment (PDQ®): Treatment - Health Professional Information [NCI] - Treatment for Untreated Adult ALL
Evidence (Imatinib mesylate):
Several studies have suggested that the addition of imatinib to conventional combination chemotherapy induction regimens results in complete response rates, event-free survival rates, and OS rates that are higher than those in historical controls.[15,16,17] At the present time, no conclusions can be drawn regarding the optimal imatinib dose or schedule.
- In a study of imatinib combined with chemotherapy from the Northern Italy Leukemia Group, patients with newly diagnosed, untreated Ph1-positive ALL were treated with an induction regimen containing idarubicin, vincristine, prednisone, and L-asparaginase. After accrual of an initial cohort, the study was modified to include the use of imatinib (600 mg per day from days 15 to 21). In consolidation, patients received imatinib (600 mg per day for 7 days) beginning 3 days prior to the start of each course of chemotherapy.
- For all patients who achieved remission, the intent was to proceed to allogeneic transplant when and if an HLA-matched donor could be identified. Patients lacking a donor received an autologous transplant. After completion of chemotherapy and transplant, all patients were to receive maintenance imatinib for as long as tolerated. After 20 patients had accrued to the imatinib arm, L-asparaginase was omitted from the induction regimen from both arms because of toxicity.
- Outcomes for the first cohort of 35 patients (imatinib-free) were compared to those of the subsequent cohort of 59 (imatinib-treated) patients. For patients treated with imatinib, OS probability was 38% at 5 years (median, 3.1 years) versus 23% in the imatinib-free group (median, 1.1 years; P = .009).[Level of evidence: 3iii]
- The drawbacks of this nonrandomized study are the small sample size (94 total patients) and the change in the treatment regimen (omission of L-asparaginase) midway through the study. However, the results suggest that inclusion of imatinib into a relatively standard chemotherapy regimen for newly diagnosed adult patients with Ph1-positive ALL may provide a significant survival advantage.
- In another study, ten patients with Ph1-positive ALL and ten patients with chronic myelogenous leukemia in lymphoid blast crisis were treated with doses of imatinib ranging from 300 mg to 1,000 mg per day. Of these 20 patients, four had complete hematologic remission and ten had marrow responses. Responses were short lived, with the majority of these patients relapsing at a median of 58 days after the start of therapy.
- In another study, 48 patients with Ph1-positive ALL were treated with 400 mg to 800 mg of imatinib per day. The overall response rate was 60%, with 9 out of 48 patients (19%) achieving a CR. The responses again were short, with a median duration of 2.2 months.