Only the beginning: 50 years of progress toward curing childhood cancer.

Dramatic progress in treating childhood cancer has evolved over decades from initial empirically derived treatments to clinical investigations incorporating disease biology with rationally designed therapeutic programs. While cure is now possible for many, it remains elusive for others. Collaboration across numerous domains is necessary for cure to be a reality for all.

Toxicity profile of high-dose methotrexate in young children with central nervous system tumors.

High-dose methotrexate (HD-MTX) is used in the treatment of children with central nervous system (CNS) tumors; however, toxicity information is limited. We characterized toxicities following 102 administrations of HD-MTX (4.6-13.5 g/m2) infused over 4 or 24 h in 38 children with a CNS tumor before 6 years of age (2010-2020). Delayed clearance of methotrexate occurred following 24% of infusions. Common Terminology Criteria for Adverse Events v5 grade 2-3 mucositis was observed in 47% of individuals, Grade 4 neutropenia in 76%, and grade 3-4 thrombocytopenia in 58%. No neurotoxicity was observed. HD-MTX can be safely used with supportive care and monitoring.

Improving infectious adverse event reporting for children and adolescents enrolled in clinical trials for acute lymphoblastic leukemia: A report from the Children's Oncology Group.

Infections cause substantial morbidity for children with acute lymphoblastic leukemia (ALL). Therefore, accurate characterization of infectious adverse events (AEs) reported on clinical trials is imperative to defining, comparing, and managing safety and toxicity. Here, we describe key processes implemented to improve reporting of infectious AEs on two active phase III Children's Oncology Group (COG) ALL trials. Processes include: (a) identifying infections as a targeted toxicity, (b) incorporation of infection-specific case report form questions, and (c) physician review of AEs with real-time data cleaning. Preliminary assessment of these processes suggests improved reporting, as well as opportunities for further improvement.

Treatment of posttransplant lymphoproliferative disorder with poor prognostic features in children and young adults: Short-course EPOCH regimens are safe and effective.

No guidelines exist for which intensive chemotherapy regimen is best in pediatric or young adult patients with high-risk posttransplant lymphoproliferative disorder (PTLD). We retrospectively reviewed patients with PTLD who received interval-compressed short-course etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin (SC-EPOCH) regimens at our institution. Eight patients were included with median age of 12 years. All patients achieved a complete response with a manageable toxicity profile. Two patients developed second, clonally unrelated, EBV-positive PTLD and one patient had recurrence at 6 months off therapy. No graft rejection occurred during therapy. All eight patients are alive with median follow-up of 29 months.

Results of a phase 2, multicenter, single-arm, open-label study of lenalidomide in pediatric patients with relapsed or refractory acute myeloid leukemia.

BACKGROUND: Outcomes after relapse remain poor in pediatric patients with acute myeloid leukemia (AML), and new therapeutic approaches are needed. Lenalidomide has demonstrated activity in adults with lower risk myelodysplastic syndromes and older adults with relapsed or refractory (R/R) AML. METHODS: In this phase 2 study (NCT02538965), pediatric patients with R/R AML who received two or more prior therapies were treated with lenalidomide (starting dose 2 mg/kg/day on days 1-21 of each 28-day cycle) for a maximum of 12 cycles. The primary endpoint was rate of complete response (CR) and CR with incomplete blood count recovery (CRi) within the first four cycles. RESULTS: Seventeen patients enrolled and received one or more dose of lenalidomide. Median age was 12 years (range 5-18 years), median white blood cell count was 3.7 × 109 /L, and median peripheral blood blast count was 1.0 × 109 /L. One patient (5.9%) with a complex karyotype including del(5q) achieved CRi after two cycles of lenalidomide. This responder proceeded to a second hematopoietic stem cell transplantation and has remained without evidence of disease for 3 years. All patients experienced one or more of grades 3-4 treatment-emergent adverse event (TEAE). The most common grades 3-4 TEAEs were thrombocytopenia (58.8%), febrile neutropenia (47.1%), anemia (41.2%), and hypokalemia (41.2%). CONCLUSIONS: In this population of pediatric patients with R/R AML, safety data were consistent with the known safety profile of lenalidomide. As only one patient responded, further evaluation of lenalidomide at the dose and schedule studied is not warranted in pediatric AML, with the possible exception of patients with del(5q).

Chimeric Antigen Receptor T Cell Therapy in Patients with Multiply Relapsed or Refractory Extramedullary Leukemia.

Autologous CD19-directed chimeric antigen receptor T lymphocyte (CAR-T) therapy is an approved and effective treatment for the management of patients with refractory and multiply relapsed B cell precursor acute lymphoblastic leukemia (B-ALL). Experience using this therapy in pediatric patients with extramedullary (EM) disease is limited, in part because these patients have frequently been excluded from clinical trials owing to concerns for an increased risk of immune effector cell-associated neurotoxicity syndrome (ICANS). We infused 7 patients with refractory or multiply relapsed B-ALL who presented with isolated EM relapse with tisagenlecleucel. Six patients had isolated central nervous system (CNS) leukemia, and 1 patient had an isolated testicular relapse. An initial complete response was seen in all patients, with 5 patients remaining in CAR-T-induced remission at a median of 18 months from first infusion. Reversible ICANS was seen in 1 patient with CNS leukemia. Durable B cell aplasia occurred in 3 patients, with a median time to B cell recovery of 6.5 months in the other patients. These data suggest that CAR-T therapy has promising safety and efficacy in treating EM leukemia, although definitive conclusions are limited by the small size of the cohort and limited follow-up period.

Experience with ponatinib in paediatric patients with leukaemia.

Ponatinib has proven to be effective in adults with Philadelphia chromosome-positive leukaemias, but data in paediatrics are scarce. Among paediatric patients with chronic myeloid leukaemia (n = 9) or acute lymphoblastic leukaemia (n = 12) treated with varying doses of ponatinib in 13 centres, 71% showed a decrease in disease burden after a median of three months. Ponatinib was well tolerated, with grade 3 toxicities occurring in 29% of patients. Toxicities were similar to those reported in adults, with the exception of arterial thrombotic events, which were not observed. Ponatinib has a favourable safety profile in this paediatric cohort, but dose-finding studies are needed.

Bortezomib reinduction chemotherapy in high-risk ALL in first relapse: a report from the Children's Oncology Group.

While survival in paediatric acute lymphoblastic leukaemia (ALL) is excellent, survival following relapse is poor. Previous studies suggest proteasome inhibition with chemotherapy improves relapse ALL response rates. This phase 2 Children's Oncology Group study tested the hypothesis that adding the proteasome inhibitor bortezomib to chemotherapy increases complete response rates (CR2). Evaluable patients (n = 135, 103 B-ALL, 22 T-ALL, 10 T-lymphoblastic lymphoma) were treated with reinduction chemotherapy plus bortezomib. Overall CR2 rates were 68 ± 5% for precursor B-ALL patients (<21 years of age), 63 ± 7% for very early relapse (<18 months from diagnosis) and 72 ± 6% for early relapse (18-36 months from diagnosis). Relapsed T-ALL patients had an encouraging CR2 rate of 68 ± 10%. End of induction minimal residual disease (MRD) significantly predicted survival. MRD negative (MRDneg; MRD <0·01%) rates increased from 29% (post-cycle 1) to 64% following cycle 3. Very early relapse, end-of-induction MRDneg precursor B-ALL patients had 70 ± 14% 3-year event-free (EFS) and overall survival (OS) rates, vs. 3-year EFS/OS of 0-3% (P = 0·0001) for MRDpos (MRD ≥0·01) patients. Early relapse patients had similar outcomes (MRDneg 3-year EFS/OS 58-65% vs. MRDpos 10-19%, EFS P = 0·0014). These data suggest that adding bortezomib to chemotherapy in certain ALL subgroups, such as T-cell ALL, is worthy of further investigation. This study is registered at http://www.clinical.trials.gov as NCT00873093.

Delayed methotrexate clearance in patients with acute lymphoblastic leukemia concurrently receiving dasatinib.

We aimed to determine whether patients receiving dasatinib or imatinib concurrently with high-dose methotrexate (HDMTX) had slower methotrexate clearance than patients not receiving a tyrosine kinase inhibitor (TKI) during the HDMTX infusion. Patients concurrently receiving dasatinib and HDMTX (N = 7) had significantly slower MTX clearance (P = 0.008) than patients not receiving a TKI (N = 111). Two patients receiving a TKI during a HDMTX infusion required glucarpidase. In vitro studies showed that dasatinib significantly inhibited methotrexate uptake by SLCO1B1-expressing cells (P = 0.009). There may be an interaction between dasatinib and HDMTX, mediated by the transporter SLCO1B1, that causes a delay in MTX clearance.

Castleman disease in pediatrics: Insights on presentation, treatment, and outcomes from a two-site retrospective cohort study.

BACKGROUND: Castleman disease (CD) is an uncommon lymphoproliferative disorder that is rare in pediatric populations; the literature describing this population is sparse. We sought to describe pediatric CD, including unicentric CD (UCD) and human herpes virus-8 (HHV8)-negative multicentric CD (MCD), in a multi-institutional cohort. METHODS: We retrospectively reviewed 24 patients, aged 0 to 26 years at diagnosis, who were diagnosed with CD between January 1, 2005, and May 16, 2017, at two tertiary children's hospitals. Demographic and clinical data were collected. RESULTS: Most patients (75%, 18/24) presented with UCD. All patients with MCD were HHV8-negative. The most common histopathologic variant was hyaline vascular (75%, 18/24). Plasma cell variant occurred in 33% (2/6 [95% confidence intervals (CI), 4-78%]) of patients with HHV8-negative MCD and 17% (3/18 [95% CI, 4-41%]) of patients with UCD. Systemic symptoms were present in 4 of 6 of patients with HHV8-negative MCD and 8 of 18 of patients with UCD. Anemia and laboratory inflammation occurred in both UCD and MCD patients, with nonsignificantly higher rates of anemia and elevated C-reactive protein in MCD patients. All but two UCD patients underwent gross total resection as definitive therapy. Among HHV8-negative MCD patients, a combination of resection, chemotherapy, and immunotherapy was used. No UCD patients and three of six HHV8-negative MCD patients experienced disease progression/relapse prior to lasting remission. There were no deaths. CONCLUSION: Pediatric patients with CD most commonly have unicentric, hyaline vascular variant disease. Pediatric patients with both UCD and MCD commonly have systemic inflammation and, despite risk of progression/relapse in MCD patients, ultimately have excellent survival.

Consensus Guideline for Use of Glucarpidase in Patients with High-Dose Methotrexate Induced Acute Kidney Injury and Delayed Methotrexate Clearance.

Acute kidney injury due to high-dose methotrexate (HDMTX) is a serious, life-threatening toxicity that can occur in pediatric and adult patients. Glucarpidase is a treatment approved by the Food and Drug Administration for high methotrexate concentrations in the context of kidney dysfunction, but the guidelines for when to use it are unclear. An expert panel was convened to provide specific, expert consensus guidelines for the use of glucarpidase in patients who develop HDMTX-induced nephrotoxicity and delayed methotrexate excretion. The guideline provides recommendations to identify the population of patients who would benefit from glucarpidase rescue by more precisely defining the absolute methotrexate concentrations associated with risk for severe or life-threatening toxicity at several time points after the start of an HDMTX infusion. For an HDMTX infusion ≤24 hours, if the 36-hour concentration is above 30 µM, 42-hour concentration is above 10 µM, or 48-hour concentration is above 5 µM and the serum creatinine is significantly elevated relative to the baseline measurement (indicative of HDMTX-induced acute kidney injury), glucarpidase may be indicated. After a 36- to 42-hour HDMTX infusion, glucarpidase may be indicated when the 48-hour methotrexate concentration is above 5 µM. Administration of glucarpidase should optimally occur within 48-60 hours from the start of the HDMTX infusion, because life-threatening toxicities may not be preventable beyond this time point. IMPLICATIONS FOR PRACTICE: Glucarpidase is a rarely used medication that is less effective when given after more than 60 hours of exposure to high-dose methotrexate, so predicting early which patients will need it is imperative. There are no currently available consensus guidelines for the use of this medication. The indication on the label does not give specific methotrexate concentrations above which it should be used. An international group of experts was convened to develop a consensus guideline that was specific and evidence-based to identify the population of patients who would benefit from glucarpidase.

Viral surveillance using PCR during treatment of AML and ALL.

BACKGROUND: While viral surveillance of cytomegalovirus (CMV), Epstein-Barr virus (EBV), and adenovirus using PCR is routine in patients undergoing hematopoetic stem cell transplant and solid organ transplant, the utility in the nontransplant pediatric leukemia population is unknown. Our institution screens patients with acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) for viral DNAemia by PCR as part of clinical care. PROCEDURE: This retrospective chart review included patients treated for newly diagnosed or relapsed AML or ALL between April 2010 and September 2014. We retrieved data for viral PCR screening, detection and quantification, duration of positivity, and prophylaxis or treatment. RESULTS: One hundred eleven patients were included in analyses. Forty (36.0%) had at least one blood PCR positive for EBV, CMV, or adenovirus. Patients with ALL had significantly higher rates of persistent viral detection and treatment than those with AML (P < 0.02, P < 0.01, respectively). International patients had significantly higher rates of viral detection (P < 0.01), persistence (P < 0.01), any treatment (P < 0.03), and antiviral treatment (P < 0.01); 16.9% of patients who received intravenous immunoglobulin (IVIG) prophylactically had viral detection compared to 63% of patients who did not receive prophylactic IVIG (P = 0.0008). CONCLUSIONS: Patients with ALL were more susceptible than those with AML to viral reactivation that was persistent or resulted in treatment. Patients with relapsed ALL, refractory ALL, or infantile ALL are most likely to benefit from asymptomatic screening for CMV and adenovirus. International patients are at higher risk for reactivation and may merit screening. EBV reactivation was not significant and does not warrant screening.

Limitations of HLH-2004 criteria in distinguishing malignancy-associated hemophagocytic lymphohistiocytosis.

Hemophagocytic lymphohistiocytosis (HLH) is characterized by dysregulated immune activation.  Primary HLH involves hereditary deficits in cytotoxic lymphocytes while secondary HLH is triggered by extrinsic factors. The HLH-2004 criteria are widely used for clinical diagnosis, yet their specificity for HLH or their ability to differentiate primary from secondary disease is unclear, potentially leading to inappropriate treatment. We describe several cases where fulfillment of HLH-2004 criteria obscured the diagnoses of underlying malignancies and delayed curative management. These issues are remedied without waiting for genetic testing results through an alternative diagnostic approach using flow cytometry-based immunologic assays and a thorough investigation for malignancy.

Cost-Effectiveness Analysis of an Adherence-Promotion Intervention for Children With Leukemia: A Markov Model-Based Simulation.

Objective: Improving medication adherence among children with B-cell precursor acute lymphoblastic leukemia (B-ALL) has the potential to reduce relapse rates but requires an investment in resources. An economic evaluation is needed to understand the potential costs and benefits of delivering adherence-promotion interventions (APIs) as part of standard clinical care. Methods: A Markov decision analytic model was used to simulate the potential incremental cost-effectiveness per quality-adjusted life year (QALY) to be gained from an API for children with B-ALL in first continuous remission compared with treatment as usual (TAU, no intervention). Model parameter estimates were informed by previously published studies. The primary outcome was incremental cost (2015 US$) per QALY gained for API compared with TAU. Results: The model predicts the API to result in superior health outcomes (4.87 vs. 4.86 QALYs) and cost savings ($43,540.73 vs. $46,675.71) as compared with TAU, and simulations indicate that, across a range of plausible parameter estimates, there is a 95% chance that the API is more effective and less costly than TAU. The API was estimated to remain more effective and less costly than TAU in situations where the prevalence of nonadherence exceeds 32% and when API improves baseline adherence in at least 3% of patients. Conclusions: Providing APIs to children with B-ALL may improve health outcomes and save costs over a 6-year period.

Radiation dose reduction through combining positron emission tomography/computed tomography (PET/CT) and diagnostic CT in children and young adults with lymphoma.

BACKGROUND: Both [F-18]2-fluoro-2-deoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) and diagnostic CT are at times required for lymphoma staging. This means some body segments are exposed twice to X-rays for generation of CT data (diagnostic CT + localization CT). OBJECTIVE: To describe a combined PET/diagnostic CT approach that modulates CT tube current along the z-axis, providing diagnostic CT of some body segments and localization CT of the remaining body segments, thereby reducing patient radiation dose. MATERIALS AND METHODS: We retrospectively compared total patient radiation dose between combined PET/diagnostic CT and separately acquired PET/CT and diagnostic CT exams. When available, we calculated effective doses for both approaches in the same patient; otherwise, we used data from patients of similar size. To confirm image quality, we compared image noise (Hounsfield unit [HU] standard deviation) as measured in the liver on both combined and separately acquired diagnostic CT images. We used t-tests for dose comparisons and two one-sided tests for image-quality equivalence testing. RESULTS: Mean total effective dose for the CT component of the combined and separately acquired diagnostic CT exams were 6.20±2.69 and 8.17±2.61 mSv, respectively (P<0.0001). Average dose savings with the combined approach was 24.8±17.8% (2.60±2.51 mSv [range: 0.32-4.72 mSv]) of total CT effective dose. Image noise was not statistically significantly different between approaches (12.2±1.8 HU vs. 11.7±1.5 HU for the combined and separately acquired diagnostic CT images, respectively). CONCLUSION: A combined PET/diagnostic CT approach as described offers dose savings at similar image quality for children and young adults with lymphoma who have indications for both PET and diagnostic CT examinations.

Urine biomarkers of acute kidney injury in noncritically ill, hospitalized children treated with chemotherapy.

BACKGROUND: Cisplatin (Cis), carboplatin (Carb), and ifosfamide (Ifos) are common nephrotoxic chemotherapies. Biomarkers of tubular injury may allow for early acute kidney injury (AKI) diagnosis. PROCEDURE: We performed a two-center (Canada, United States) pilot study to prospectively measure serum creatinine (SCr), urine neutrophil gelatinase-associated lipocalin (NGAL), and interleukin-18 (IL-18) in children receiving Cis/Carb (27 episodes), Ifos (30 episodes), and in 15 hospitalized, nonchemotherapy patients. We defined AKI using the Kidney Disease Improving Global Outcomes (KDIGO) definition. We compared postchemotherapy infusion NGAL and IL-18 concentrations (immediate postdose to 3 days later) to pre-infusion concentrations. We calculated area under the receiver operating characteristic curve (AUC) for postinfusion biomarkers to discriminate for AKI. RESULTS: Prechemotherapy infusion NGAL and IL-18 concentrations were not higher than nonchemotherapy control concentrations. Increasing chemotherapy dose was associated with increasing postinfusion (0-4 hr after infusion) NGAL (P < 0.05). Post-Ifos, immediate postdose, and daily postdose NGAL and IL-18 were significantly higher than pre-infusion biomarker concentrations (P < 0.05), during AKI episodes. NGAL and IL-18 did not rise significantly after Cis-Carb infusion, relative to predose concentrations (P > 0.05). NGAL and IL-18 measured immediately after Ifos infusion discriminated for AKI with AUCs is 0.80 (standard error = 0.13) and 0.73 (standard error = 0.16), respectively. NGAL and IL-18 were not diagnostic of Cis-Carb-associated AKI. When AUCs were adjusted for age, all biomarker AUCs (Cis-Carb and Ifos) improved. CONCLUSION: Urine NGAL and IL-18 show promise as early AKI diagnostic tests in children treated with ifosfamide and may have a potential role in drug toxicity monitoring.

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.

Lineage Switch in MLL-Rearranged Infant Leukemia Following CD19-Directed Therapy.

Rearrangements of the mixed lineage leukemia (MLL) gene occur frequently in infants with both acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML). Conversions of leukemia cell lineage are rare, but occur most commonly in the setting of MLL-rearrangement. Blinatumomab is a bidirectional antibody targeting CD19 with significant activity in relapsed B-precursor ALL. We report an infant with ALL with t(4;11)(q21;q23) refractory to cytotoxic chemotherapy who was treated with blinatumomab. Following rapid initial clearance of peripheral lymphoblasts, bone marrow evaluation demonstrated a leukemic lineage switch to CD19-negative monoblastic AML. Complete remission was achieved with myeloid-directed chemotherapy.

Azacitidine and Sorafenib Therapy in a Pediatric Patient With Refractory Acute Myeloid Leukemia With Monosomy 7 and Somatic PTPN11 Mutation.

Monosomy 7 is a well-documented cytogenetic aberration in pediatric acute myeloid leukemia (AML) and may occur in combinations with molecular abnormalities including PTPN11 mutation. PTPN11 mutations contribute to leukemogenesis through upregulation of Ras pathway signaling. We present the case of a 3-year-old female with AML with monosomy 7 and somatic PTPN11 mutation who was refractory to conventional AML chemotherapy but responded to a novel regimen of azacitidine and sorafenib followed by stem cell transplantation. Combination therapy with azacitidine and sorafenib may be an effective therapeutic strategy for patients with AML with Ras pathway abnormalities.

Successful Treatment of Disseminated Adenovirus Infection in an Infant With Acute Lymphoblastic Leukemia.

Systemic adenovirus infection in the immunocompromised host is often fatal and therapeutic options are limited. We report an infant with acute lymphoblastic leukemia who developed disseminated adenovirus infection while lymphopenic during maintenance chemotherapy 6 months following a bout of adenoviral diarrhea. His serum adenoviral load peaked at 35 million copies/mL and was associated with pancytopenia and hepatic injury. Treatment with cidofovir was effective although associated with mild renal injury. The patient recovered fully and completed chemotherapy for infant acute lymphoblastic leukemia.