Faculty Bibliography

The causes of individual relapses in children with acute lymphoblastic leukemia (ALL) remain incompletely understood. We evaluated the contribution of germline genetic factors to relapse in 2225 children treated on Children's Oncology Group trial AALL0232. We identified 302 germline single nucleotide polymorphisms (SNPs) associated with relapse after adjusting for treatment and ancestry and 715 additional SNPs associated with relapse in an ancestry-specific manner. We tested for replication of these relapse-associated SNPs in external data sets of antileukemic drug pharmacokinetics and pharmacodynamics and an independent clinical cohort. 224 SNPs were associated with rapid drug clearance or drug resistance, and 32 were replicated in the independent cohort. The adverse risk associated with black and Hispanic ancestries was attenuated by addition of the 4 SNPs most strongly associated with relapse in these populations [for blacks: model without SNPs hazard ratio (HR)=2.32, P=2.27 x 10-4, model with SNPs HR=1.07, P=0.79; for Hispanics: model without SNPs HR=1.7, P=8.23 x 10-5, model with SNPs HR=1.31, P=0.065]. Relapse SNPs associated with asparaginase resistance or allergy were overrepresented among SNPs associated with relapse in the more asparaginase intensive treatment arm (20/54 in Capizzi-methorexate arm vs 8/54 in high-dose methotrexate arm, P=0.015). Inherited genetic variation contributes to race-specific and treatment-specific relapse risk.Leukemia accepted article preview online, 18 January 2017. doi:10.1038/leu.2017.24.

CDK4/6 inhibition was synergistic with dexmethasome and everolimus but antagonistic with conventional chemotherapy in T-cell acute lymphoblastic leukemia (T-ALL) pre-clinical models. Cyclin dependent kinase inhibition in combination with glucocorticoids and mTOR inhibition offers a unique therapeutic opportunity in T-ALL.

T-cell acute lymphoblastic leukemia (T-ALL) is biologically distinct from its B lymphoblastic (B-ALL) counterpart and shows different kinetic patterns of disease response. Although very similar regimens are used to treat T-ALL and B-ALL, distinctions in response to different elements of therapy have been observed. Similar to B-ALL, the key prognostic determinant in T-ALL is minimal residual disease (MRD) response. Unlike B-ALL, other factors including age, white blood cell count at diagnosis, and genetics of the ALL blasts are not independently prognostic when MRD response is included. Recent insights into T-ALL biology, using modern genomic techniques, have identified a number of recurrent lesions that can be grouped into several targetable pathways, including Notch, Jak/Stat, PI3K/Akt/mTOR, and MAPK. With contemporary chemotherapy, outcomes for de novo T-ALL have steadily improved and now approach those observed in B-ALL, with approximately 85% 5-year event-free survival. Unfortunately, salvage has remained poor, with less than 25% event-free and overall survival rates for relapsed disease. Thus, current efforts are focused on preventing relapse by augmenting therapy for high-risk patients, sparing toxicity in favorable subsets and developing new approaches for the treatment of recurrent disease.

This retrospective study examined the longitudinal hospital outcomes (costs adjusted for inflation, hospital days, and admissions) associated with the treatment of pediatric, adolescent, and young adult acute lymphoblastic leukemia (ALL). Patients between one and 26 years of age with newly diagnosed ALL, who were treated at Primary Children's Hospital (PCH) in Salt Lake City, Utah were included. Treatment and hospitalization data were retrieved from system-wide cancer registry and enterprise data warehouse. PCH is a member of the Children's Oncology Group (COG) and patients were treated on, or according to, active COG protocols. Treatment-related hospital costs of ALL were examined by computing the average annual growth rates (AAGR). Longitudinal regressions identified patient characteristics associated with costs. A total of 505 patients (46.9% female) were included. The majority of patients had B-cell lineage ALL, 6.7% had T-ALL, and the median age at diagnosis was 4 years. Per-patient, first-year ALL hospitalization costs at PCH rose from $24,197 in 1998 to $37,924 in 2012. The AAGRs were 6.1, 13.0, and 7.6% for total, pharmacy, and room and care costs, respectively. Average days (AAGR = 5.2%) and admissions (AAGR = 3.8%) also demonstrated an increasing trend. High-risk patients had 47% higher costs per 6-month period in the first 5 years from diagnosis than standard-risk patients (P < 0.001). Similarly, relapsed ALL and stem cell transplantations were associated with significantly higher costs than nonrelapsed and no transplantations, respectively (P < 0.001). Increasing treatment-related costs of ALL demonstrate an area for further investigation. Value-based interventions such as identifying low-risk fever and neutropenia patients and managing them in outpatient settings should be evaluated for reducing the hospital burden of ALL.

AALL08P1 was designed to determine whether biweekly intensified pegaspargase (I-PEG) was feasible and safe in pediatric patients with newly diagnosed high-risk B-precursor lymphoblastic leukemia when given with Children's Oncology Group hemiaugmented BFM therapy. High-risk average (HR-Avg) patients received standard pegaspargase dosing (6 doses), whereas high-risk high (HR-High) patients received I-PEG biweekly from the start of Consolidation until day 1 of Maintenance. Feasibility and safety were defined in advance as >/=65% of patients tolerating at least 8 doses of I-PEG and 90% requiring /=8 total doses of I-PEG and 50% (15/30) took