Dexamethasone and High-Dose Methotrexate Improve Outcome for Children and Young Adults With High-Risk B-Acute Lymphoblastic Leukemia: A Report From Children's Oncology Group Study AALL0232

A randomized controlled trial testing an adherence-optimized Vitamin D regimen to mitigate bone change in adolescents being treated for acute lymphoblastic leukemia

Adolescents with acute lymphoblastic leukemia (ALL) develop osteopenia early in therapy, potentially exacerbated by high rates of concurrent Vitamin D deficiency. We conducted a randomized clinical trial testing a Vitamin D-based intervention to improve Vitamin D status and reduce bone density decline. Poor adherence to home supplementation necessitated a change to directly observed therapy (DOT) with intermittent, high-dose Vitamin D3 randomized versus standard of care (SOC). Compared to SOC, DOT Vitamin D3 successfully increased trough Vitamin 25(OH)D levels (p = .026) with no residual Vitamin D deficiency, 100% adherence to DOT Vitamin D3, and without associated toxicity. However, neither Vitamin D status nor supplementation impacted bone density. Thus, this adherence-optimized intervention is feasible and effective to correct Vitamin D deficiency in adolescents during ALL therapy. Repletion of Vitamin D and calcium alone did not mitigate osteopenia, however, and new, comprehensive approaches are needed to address treatment-associated osteopenia during ALL therapy.

An update on PCR use for minimal residual disease monitoring in acute lymphoblastic leukemia

INTRODUCTION

Acute lymphoblastic leukemia (ALL) is the first neoplasm where the assessment of early response to therapy by minimal residual disease (MRD) monitoring has proven to be a fundamental tool for guiding therapeutic choices. In recent years, thanks to real-time quantitative PCR (qPCR), MRD monitoring has further achieved higher levels of sensitivity and standardization. However, some outstanding issues still remain to be addressed and emerging technologies hold the promise of improving MRD detection in ALL patients. Areas covered: Through a comprehensive review of the literature, we analyze the state-of-the-art of molecular MRD assessment in ALL to better understand how, in the upcoming years, some of its limitations could be tackled by emerging molecular technologies. Furthermore, we highlight the future role of molecular MRD monitoring in the context of personalized protocols, taking into account the growing genetic complexity in ALL. Expert commentary: Although new molecular technologies are promising tools for MRD assessment, qPCR still remains the gold standard for evaluating MRD in ALL. High-throughput sequencing and droplet digital PCR allow to identify new prognostic factors and/or MRD targets at diagnosis and to perform earlier MRD evaluations, thereby optimizing patient stratification and earlier MRD-based clinical intervention to improve ALL patient outcomes.

High-dose methotrexate therapy significantly improved survival of adult acute lymphoblastic leukemia: a phase III study by JALSG

High-dose methotrexate (Hd-MTX) therapy has recently been applied to the treatment of adult acute lymphoblastic leukemia (ALL) based on pediatric protocols; however, its effectiveness for adult ALL has not yet been confirmed in a rigorous manner. We herein conducted a randomized phase III trial comparing Hd-MTX therapy with intermediate-dose (Id)-MTX therapy. This study was registered at UMIN-CTR (ID: C000000063). Philadelphia chromosome (Ph)-negative ALL patients aged between 25 and 64 years of age were enrolled. Patients who achieved complete remission (CR) were randomly assigned to receive therapy containing Hd-MTX (3 g/m²) or Id-MTX (0.5 g/m²). A total of 360 patients were enrolled. The CR rate was 86%. A total of 115 and 114 patients were assigned to the Hd-MTX and Id-MTX groups, respectively. The estimated 5-year disease-free survival rate of the Hd-MTX group was 58%, which was significantly better than that of the Id-MTX group at 32% (P=0.0218). The frequencies of severe adverse events were not significantly different. We herein demonstrated the effectiveness and safety of Hd-MTX therapy for adult Ph-negative ALL. Our results provide a strong rationale for protocols containing Hd-MTX therapy being applied to the treatment of adult ALL.

How is the Ph-like signature being incorporated into ALL therapy?

Philadelphia chromosome-like acute lymphoblastic leukemia (Ph-like ALL) is a recently identified high risk disease subtype characterized by a gene expression profile similar to that observed in Philadelphia chromosome-positive (Ph-positive) ALL, but without an underlying BCR-ABL1 translocation. Adults and children with Ph-like ALL harbor a diversity of alterations that all lead to activated kinase signaling. Outcomes for patients with Ph-like ALL are poor, which has prompted investigation into the role of tyrosine kinase inhibitor (TKI)-based therapies for this disease. Several clinical trials are now ongoing that include screening for the Ph-like signature and treatment of patients with Ph-like ALL with TKI therapy. This review examines how testing for Ph-like ALL is being incorporated into clinical trials.

Redefining treatment failure for pediatric acute leukemia in the era of minimal residual disease testing

Technologies for the detection of minimal residual disease (MRD) in leukemia and our understanding of the prognostic implications of MRD at different phases of treatment have significantly improved over the past decade. As a result, definitions of treatment failure based on bone marrow morphology by light microscopy are becoming increasingly inadequate for clinical care and trial design. In addition, novel therapies that may have increased efficacy and decreased toxicity in the setting of MRD compared to overt disease are changing clinical practice and challenging investigators to redefine treatment failure, the role of disease surveillance in remission, and clinical trial eligibility in the era of MRD.

Neurocognitive Functioning of Children Treated for High-Risk B-Acute Lymphoblastic Leukemia Randomly Assigned to Different Methotrexate and Corticosteroid Treatment Strategies: A Report From the Children's Oncology Group

Purpose Survivors of childhood acute lymphoblastic leukemia (ALL) are at risk for neurocognitive deficits that are associated with treatment, individual, and environmental factors. This study examined the impact of different methotrexate (MTX) and corticosteroid treatment strategies on neurocognitive functioning in children with high-risk B-lineage ALL. Methods Participants were randomly assigned to receive high-dose MTX with leucovorin rescue or escalating dose MTX with PEG asparaginase without leucovorin rescue. Patients were also randomly assigned to corticosteroid therapy that included either dexamethasone or prednisone. A neurocognitive evaluation of intellectual functioning (IQ), working memory, and processing speed (PS) was conducted 8 to 24 months after treatment completion (n = 192). Results The method of MTX delivery and corticosteroid assignment were unrelated to differences in neurocognitive outcomes after controlling for ethnicity, race, age, gender, insurance status, and time off treatment; however, survivors who were age < 10 years at diagnosis (n = 89) had significantly lower estimated IQ ( P < .001) and PS scores ( P = .02) compared with participants age ≥ 10 years. In addition, participants who were covered by US public health insurance had estimated IQs that were significantly lower ( P < .001) than those with US private or military insurance. Conclusion Children with high-risk B-lineage ALL who were age < 10 years at diagnosis are at risk for deficits in IQ and PS in the absence of cranial radiation, regardless of MTX delivery or corticosteroid type. These data may serve as a basis for developing screening protocols to identify children who are at high risk for deficits so that early intervention can be initiated to mitigate the impact of therapy on neurocognitive outcomes.

Novel therapy for childhood acute lymphoblastic leukemia

INTRODUCTION

During recent decades, the prognosis of childhood acute lymphoblastic leukemia (ALL) has improved dramatically, nowadays, reaching a cure rate of almost 90%. These results are due to a better management and combination of old therapies, refined risk-group stratification and emergence of minimal residual disease (MRD) combined with treatment's intensification for high-risk subgroups. However, the subgroup of patients with refractory/relapsed ALL still presents a dismal prognosis indicating necessity for innovative therapeutic approaches. Areas covered: We performed an exhaustive review of current first-line therapies for childhood ALL in the worldwide main consortia, summarized the major advances for front-line and relapse treatment and highlighted recent and promising innovative therapies with an overview of the most promising ongoing clinical trials. Expert opinion: Two major avenues marked the beginning of 21^st century. First, is the introduction of tyrosine-kinase inhibitor coupled to chemotherapy for treatment of Philadelphia positive ALL opening new treatment possibilities for the recently identified subgroup of Ph-like ALL. Second, is the breakthrough of immunotherapy, notably CAR T-cell and specific antibody-based therapy, with remarkable success observed in initial studies. This review gives an insight on current knowledge in these innovative therapeutic directions, summarizes currently ongoing clinical trials and addresses challenges these approaches are faced with.

The role of the MTHFR C677T polymorphism in methotrexate-induced toxicity in pediatric osteosarcoma patients

AIM

Osteosarcoma patients receive high doses of methotrexate (MTX). However, pharmacogenetic information remains limited and has mainly been investigated in leukemia so far.

PATIENTS & METHODS

We investigated the link between the MTHFR C677T genotype, toxicity levels (mucositis, MTX plasma level, hematological toxicity and hepatotoxicity) and survival of 48 pediatric osteosarcoma patients.

RESULTS

The TT genotype did not show more toxicity compared with the CC/CT genotype. However, plasma MTX levels were related with mucositis, but not with hematological toxicity, nor hepatotoxicity. Survival rates did not differ between homozygous and non-homozygous patients. Yet, homozygous patients had higher relapse risk.

CONCLUSION

The MTHFR C667T polymorphism is not predictive for toxicity or overall survival, but could be used for relapse risk stratification.

Genetics of ancestry-specific risk for relapse in acute lymphoblastic leukemia

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 × 10-4, model with SNPs HR=1.07, P=0.79; for Hispanics: model without SNPs HR=1.7, P=8.23 × 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.

Managing CNS disease in adults with acute lymphoblastic leukemia

The central nervous system (CNS) is an important site of involvement by acute lymphoblastic leukemia (ALL) in adults. The prevalence is sufficiently high that prophylactic treatment is routinely given to this sanctuary site in order to eradicate occult disease that might otherwise lead to a relapse. A lumbar puncture should be routinely performed in all newly diagnosed patients with ALL. The risks of CNS leukemia vary by phenotype and genotype. Preventive treatment of the CNS during post-remission therapy has become an integral part of all current ALL treatment protocols. Most treatment regimens combine multiple doses of intrathecal chemotherapy with high-dose systemic methotrexate and/or cytarabine. Cranial irradiation is less commonly used for prophylaxis but is still the most effective treatment for overt CNS leukemia. Recurrences within the CNS usually coincide with or predict soon afterwards for systemic relapse in the marrow and blood.

Impact of Initial CSF Findings on Outcome Among Patients With National Cancer Institute Standard- and High-Risk B-Cell Acute Lymphoblastic Leukemia: A Report From the Children's Oncology Group

Purpose To determine the prognostic significance of blasts, and of white and red blood cells, in CSF samples at diagnosis of acute lymphoblastic leukemia (ALL), a uniform CSF and risk group classification schema was incorporated into Children's Oncology Group B-cell ALL (B-ALL) clinical trials. Methods CSF status was designated as follows: CNS1, no blasts; CNS2a to 2c, < 5 WBCs/μL and blasts with/without ≥ 10 RBCs/μL or ≥ 5 WBCs/μL plus blasts, with WBCs ≥ 5 times the number of RBCs; CNS3a to 3c, ≥ 5 WBCs/μL plus blasts with/without ≥ 10 RBCs/μL or clinical signs of CNS disease. CNS2 status did not affect therapy; patients with CNS3 status received two extra intrathecal treatments during induction and augmented postinduction therapy with 18 Gy of cranial radiation. Results Among 8,379 evaluable patients enrolled from 2004 to 2010, 7,395 (88.3%) had CNS1 status; 857 (10.2%), CNS2; and 127 (1.5%), CNS3. The 5-year event-free and overall survival rates were, respectively, 85% and 92.7% for CNS1, 76% and 86.8% for CNS2, and 76% and 82.1% for CNS3 ( P < .001). In multivariable analysis that included age, race/ethnicity, initial WBC, and day-29 minimal residual disease < 0.1%, CSF blast, regardless of cell count, was an independent adverse predictor of outcome for patients with standard- or high-risk disease according to National Cancer Institute criteria. The EFS difference reflected a significant difference in the incidence of CNS, not marrow, relapse in patients with CNS1 versus CNS2 and/or CNS3 status. Conclusion Low levels of CNS leukemia, regardless of RBCs, predict inferior outcome and higher rates of CNS relapse. These data suggest that additional augmentation of CNS-directed therapy is warranted for CNS2 disease.

Neurotoxicity after high-dose methotrexate (MTX) is adequately explained by insufficient folinic acid rescue

PURPOSE

To challenge the view that the dose of folinic acid rescue after high-dose methotrexate (MTX) has no significance in the prevention of neurotoxicity and to present the minority view that neurotoxicity can be prevented by an adequate dose of folinic acid, without compromising treatment results. Several fallacies that led to the misunderstanding of post MTX neurotoxicity are presented.

METHODS

Data mining using search engines was used to find relevant publications, and an e-mail survey of more than 60 authors of articles in this field was performed. All relevant articles identified were read in their entirety.

RESULTS

Examples of clinical studies with neurotoxicity following inadequate rescue are given. Some studies demonstrated no neurotoxicity when adequate doses of folinic acid rescue were started 24-36 h after the start of HDMTX rescue even after mega doses of MTX. Rescue started after 42 h was associated with neurotoxicity except in patients with low serum MTX levels after 24 and 36 h. ALL protocols with neurotoxicity, especially BFM-like protocols, are presented. Protocol is reported in which single protocol changes prevented neurotoxicity.

CONCLUSIONS

From the published data, when folinic acid rescue is given in a sufficiently high enough dose and is started 24-36 h after the beginning of the methotrexate exposure, and virtually all forms of post MTX neurotoxicity can be prevented without compromising therapeutic results.

Genome-Wide Study Links PNPLA3 Variant With Elevated Hepatic Transaminase After Acute Lymphoblastic Leukemia Therapy

Remission induction therapy for acute lymphoblastic leukemia (ALL) includes medications that may cause hepatotoxicity, including asparaginase. We used a genome-wide association study to identify loci associated with elevated alanine transaminase (ALT) levels after induction therapy in children with ALL enrolled on St. Jude Children's Research Hospital (SJCRH) protocols. Germline DNA was genotyped using arrays and exome sequencing. Adjusting for age, body mass index, ancestry, asparaginase preparation, and dosage, the PNPLA3 rs738409 (C>G) I148M variant, previously associated with fatty liver disease risk, had the strongest genetic association with ALT (P = 2.5 × 10^-8 ). The PNPLA3 rs738409 variant explained 3.8% of the variability in ALT, and partly explained race-related differences in ALT. The PNPLA3 rs738409 association was replicated in an independent cohort of 2,285 patients treated on Children's Oncology Group protocol AALL0232 (P = 0.024). This is an example of a pharmacogenetic variant overlapping with a disease risk variant.

Incidence of asparaginase-related hepatotoxicity, pancreatitis, and thrombotic events in adults with acute lymphoblastic leukemia treated with a pediatric-inspired regimen

Asparaginase is a critical component of acute lymphoblastic leukemia (ALL) treatment in children; however, its use in adults is often avoided as a result of toxicities including hepatotoxicity, thrombosis, and pancreatitis which have been reported more commonly in adults than in children. In this retrospective analysis, short-acting L-asparaginase (L-ASP) and long-acting polyethylene glycol (PEG)-asparaginase (PEG-ASP) were compared for grade 3-4 toxicities and characterized by patient and drug-related factors to identify strategies for toxicity avoidance in adults with ALL. Asparaginase was administered during sequential courses of chemotherapy using a pediatric-inspired treatment regimen. Forty-eight patients who received PEG-ASP and nine patients who received L-ASP were identified. The rates of toxicity were as follows for the PEG-ASP and L-ASP groups, respectively: hepatotoxicity (60% vs. 33%, P = 0.275), pancreatitis (17% vs. 22%, P = 0.650), thrombosis (19.0% vs. 0%, P = 0.328), or any grade 3-4 toxicity (71% vs. 44%, P = 0.143). Toxicity did not correlate with dose, either by individual dose based on flat or BSA-based measures. Logistic regression identified obesity as a risk factor for heptatotoxicity (OR = 8.44, 95% CI: 1.395-51.117). Hypofibrinogenemia was identified as a pharmacodynamic marker for predicting hepatotoxicity. In conclusion, grade 3-4 toxicity was not statistically different between adult ALL patients receiving PEG-ASP and L-ASP, but toxicity was strongly associated with obesity and hypofibrinogenemia, not dose.

Adoption of pediatric-inspired acute lymphoblastic leukemia regimens by adult oncologists treating adolescents and young adults: A population-based study

BACKGROUND

Studies have demonstrated superior outcomes for adolescent and young adult (AYA) patients with acute lymphoblastic leukemia (ALL) who are treated using pediatric versus adult therapeutic regimens. To the best of our knowledge, whether adult oncologists in the United States have adopted this approach to ALL in AYA patients is currently unknown. The objective of the current study was to provide a population-based description of ALL treatment patterns in AYA individuals over the past decade.

METHODS

Data regarding AYA patients aged 15 to 39 years and diagnosed with ALL between 2004 and 2014 while living in the Greater Bay Area were obtained from the Greater Bay Area Cancer Registry (GBACR). Treating facilities were designated as pediatric or adult centers; induction treatment regimens were abstracted from registry text data fields.

RESULTS

Of 304 patients diagnosed in the GBACR catchment region, complete treatment data were available for 229 (75%). The location of care was identified for 296 patients (97%) treated at 31 unique centers. Approximately 70% of AYA patients received induction therapy at an adult treatment center. All AYA patients who were treated at pediatric centers received pediatric ALL regimens. Among AYA patients treated by adult oncologists with complete treatment data, none received a pediatric regimen before 2008. Between 2008 and 2012, while the US Adult Intergroup C10403 pediatric-inspired ALL protocol was open to accrual, 31% of AYA patients treated by adult oncologists received pediatric regimens. This rate fell to 21% from 2013 through 2014. Adult facilities treating ≥ 2 AYA patients with ALL per year captured in the GBACR were more likely to administer pediatric regimens than lower volume centers (P = .03).

CONCLUSIONS

As of 2014, only a minority of AYA patients with ALL received pediatric ALL regimens at adult cancer centers. Cancer 2017;122-130. © 2016 American Cancer Society.

T-cell acute lymphoblastic leukemia

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.

Recent advances in the management of pediatric acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) is the most common malignancy in childhood. Despite enormous improvement of prognosis during the last half century, ALL remains a major cause of childhood cancer-related mortality. During the past decade, whole genomic methods have enhanced our knowledge of disease biology. Stratification of therapy according to early treatment response measured by minimal residual disease allows risk group assignment into different treatment arms, ranging from reduction to intensification of treatment. Progress has been achieved in academic clinical trials by optimization of combined chemotherapy, which continues to be the mainstay of contemporary treatment. The availability of suitable volunteer main histocompatibility antigen-matched unrelated donors has increased the rates of hematopoietic stem cell transplantation (HSCT) over the past two decades. Allogeneic HSCT has become an alternative treatment for selected, very-high-risk patients. However, intensive treatment burdens children with severe acute toxic effects that can cause permanent organ damage and even toxic death. Immunotherapeutic approaches have recently come to the forefront in ALL therapy. Monoclonal antibodies blinatumomab and inotuzumab ozogamicin as well as gene-modified T cells directed to specific target antigens have shown efficacy against resistant/relapsed leukemia in phase I/II studies. Integration of these newer modalities into combined regimens with chemotherapy may rescue a subset of children not curable by contemporary therapy. Another major challenge will be to incorporate less toxic regimens into the therapy of patients with low-risk disease who have a nearly 100% chance of being cured, and the ultimate goal is to improve their quality of life while maintaining a high cure rate.