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The online version of this article has a supplementary appendix. BackgroundDasatinib 100 mg once daily achieves intermittent BCR-ABL kinase inhibition and is approved for chronic-phase chronic myeloid leukemia patients resistant or intolerant to imatinib. To better assess durability of response to and tolerability of dasatinib, data from a 2-year minimum follow-up for a dose-optimization study in chronic-phase chronic myeloid leukemia are reported here. Design and MethodsIn a phase 3 study, 670 chronic-phase chronic myeloid leukemia patients with resistance, intolerance, or suboptimal response to imatinib were randomized to dasatinib 100 mg once-daily, 50 mg twice-daily, 140 mg once-daily, or 70 mg twice-daily. ResultsData from a 2-year minimum follow-up demonstrate that dasatinib 100 mg once daily achieves major cytogenetic response and complete cytogenetic response rates comparable to those in the other treatment arms, and reduces the frequency of key side effects. Comparable 2-year progression-free survival and overall survival rates were observed (80% and 91%, respectively, for 100 mg once daily, and 75%-76% and 88%-94%, respectively, in other arms). Complete cytogenetic responses were achieved rapidly, typically by 6 months. In patients treated with dasatinib 100 mg once daily for 6 months without complete cytogenetic response, the likelihood of achieving such a response by 2 years was 50% for patients who had achieved a partial cytogenetic response, and only 8% or less for patients with minor, minimal, or no cytogenetic response. Less than 3% of patients suffered disease transformation to accelerated or blast phase. ConclusionsIntermittent kinase inhibition can achieve rapid and durable responses, indistinguishable from those achieved with more continuous inhibition. Clintrials.gov identifier: NCT00123474.Key words: chronic myeloid leukemia, chronic phase, dasatinib, cytogenetic response, inhibition. Haematologica. 2010; 95:232-240. doi:10.3324/haematol.2009 Citation

Acute lymphoblastic leukemia (ALL) is a hematologic malignancy that predominantly occurs in children between 2 and 10 years of age. L-asparaginase is an integral component of treatment for patients with ALL and since its introduction into pediatric treatment protocols in the 1960s, survival rates in children have progressively risen to nearly 90%. Outcomes for adolescent and young adult (AYA) patients, aged 15-39 years and diagnosed with ALL, have historically been less favorable. However, recent reports suggest substantially increased survival in AYA patients treated on pediatric-inspired protocols that include a greater cumulative dose of asparaginase. All  currently available asparaginases share the same mechanism of action - the deamination and depletion of serum asparagine levels - yet each displays a markedly different pharmacokinetic profile. Pegylated asparaginase derived from the bacterium Escherichia coli is used as first-line therapy; however, up to 30% of patients develop a treatment-limiting hypersensitivity reaction. Patients who experience a hypersensitivity reaction to an E. coli-derived asparaginase can continue treatment with Erwinia chrysanthemi asparaginase. Erwinia asparaginase is immunologically distinct from E. coli-derived asparaginases and exhibits no cross-reactivity. Studies have shown that with adequate dosing, therapeutic levels of Erwinia asparaginase activity can be achieved, and patients switched to Erwinia asparaginase due to hypersensitivity can obtain outcomes similar to patients who do not experience a hypersensitivity reaction. Therapeutic drug monitoring may be required to ensure that therapeutic levels of asparaginase activity are maintained.

Children's Cancer Group-1991 selected 2 components from the Children's Cancer Group studies shown to be effective in high-risk acute lymphoblastic leukemia and examined them in children with National Cancer Institute standard-risk acute B-precursor lymphoblastic leukemia. These were (

BACKGROUND Dasatinib, a highly potent BCR-ABL inhibitor, is an effective treatment for patients with chronic myeloid leukemia in chronic phase (CML CP) after resistance, suboptimal response, or intolerance to prior imatinib. In a phase 3 dose optimization trial in patients with CML CP (CA180-034), the occurrence of pleural effusion was significantly minimized with dasatinib 100 mg once daily (QD) compared with other treatment arms (70 mg twice daily [twice daily], 140 mg QD, or 50 mg twice daily). METHODS To investigate the occurrence and management of pleural effusion during dasatinib treatment, and efficacy in patients with or without pleural effusion, data from CA180-034 were analyzed. RESULTS With 24-month minimum follow-up, 14% of patients treated with dasatinib 100 mg QD incurred pleural effusion (grade 3: 2%; grade 4: 0%) compared with 23% to 26% in other study arms. The pleural effusion rate showed only a minimal increment from 12 to 24 months. In the 100 mg QD study arm, median time to pleural effusion (any grade) was 315 days, and after pleural effusion, 52% of patients had a transient dose interruption, 35% had a dose reduction, 57% received a diuretic, and 26% received a corticosteroid. Three patients in the 100 mg QD study arm discontinued treatment after pleural effusion. Across all study arms, patients with or without pleural effusion demonstrated similar progression-free and overall survival, and cytogenetic response rates were higher in patients with a pleural effusion. CONCLUSIONS Pleural effusion is minimized with dasatinib 100 mg QD dosing and its occurrence does not affect short- or long-term efficacy.

PURPOSE Children’s Oncology Group (COG) AALL0331 tested whether intensified postinduction therapy that improves survival in children with high-risk B-cell acute lymphoblastic leukemia (ALL) would also improve outcomes for those with standard-risk (SR) ALL. PATIENTS AND METHODS AALL0331 enrolled 5,377 patients between 2005 and 2010. All patients received a 3-drug induction with dexamethasone, vincristine, and pegaspargase (PEG) and were then classified as SR low, SR average, or SR high. Patients with SR-average disease were randomly assigned to receive either standard 4-week consolidation (SC) or 8-week intensified augmented Berlin-Frankfurt-Münster (BFM) consolidation (IC). Those with SR-high disease were nonrandomly assigned to the full COG-augmented BFM regimen, including 2 interim maintenance and delayed intensification phases. RESULTS The 6-year event-free survival (EFS) rate for all patients enrolled in AALL0331 was 88.96% ± 0.46%, and overall survival (OS) was 95.54% ± 0.31%. For patients with SR-average disease, the 6-year continuous complete remission (CCR) and OS rates for SC versus IC were 87.8% ± 1.3% versus 89.1% ± 1.2% ( P = .52) and 95.8% ± 0.8% versus 95.2% ± 0.8% ( P = 1.0), respectively. Those with SR-average disease with end-induction minimal residual disease (MRD) of 0.01% to < 0.1% had an inferior outcome compared with those with lower MRD and no improvement with IC (6-year CCR: SC, 77.5% ± 4.8%; IC, 77.1% ± 4.8%; P = .71). At 6 years, the CCR and OS rates among 635 nonrandomly treated patients with SR-high disease were 85.55% ± 1.49% and 92.97% ± 1.08%, respectively. CONCLUSION The 6-year OS rate for > 5,000 children with SR ALL enrolled in AALL0331 exceeded 95%. The addition of IC to treatment for patients with SR-average disease did not improve CCR or OS, even in patients with higher MRD, in whom it might have been predicted to provide more value. The EFS and OS rates are excellent for this group of patients with SR ALL, with particularly good outcomes for those with SR-high disease.

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The survival of pediatric patients with multiply relapsed and/or refractory (R/R) B-cell acute lymphoblastic leukemia has historically been very poor; however, data are limited in the current era. We conducted a retrospective study to determine the outcome of multiply R/R childhood B-ALL treated at 24 TACL institutions between 2005 and 2013. Patient information, treatment, and response were collected. Prognostic factors influencing the complete remission (CR) rate and event-free survival (EFS) were analyzed. The analytic set included 578 salvage treatment attempts among 325 patients. CR rates (mean ± SE) were 51 ± 4% for patients with bone marrow R/R B-ALL who underwent a second salvage attempt, 37 ± 6% for a third attempt, and 31 ± 6% for the fourth through eighth attempts combined. For patients achieving a CR after their second, third, and fourth through eighth attempts, the 2 year EFS was 41 ± 6%, 13 ± 7%, and 27 ± 13% respectively. Our results showed slight improvement when compared to previous studies. This is the largest and most recent study to date that evaluates the outcome of this patient population. Our data will provide detailed reference for the evaluation of new agents being developed for childhood B-ALL.