Model-Informed Precision Dosing Guidance of Ethosuximide Developed from a Randomized Controlled Clinical Trial of Childhood Absence Epilepsy

Ethosuximide was identified as the optimal option for new-onset childhood absence epilepsy (CAE) in a randomized, two-phase dose escalation comparative effectiveness trial of ethosuximide, lamotrigine, and valproic acid. However, 47% of ethosuximide initial monotherapy participants experienced short-term treatment failure. This study aimed to characterize the initial monotherapy ethosuximide exposure-response relationship and to propose model-informed precision dosing guidance. Dose titration occurred over a 16-20-week period until patients experienced seizure freedom or intolerable side effects. Subjects with initial monotherapy failure were randomized to one of the other two medications and dose escalation was repeated. A population pharmacokinetic model was created using plasma concentration data (n = 1,320), collected at 4-week intervals from 211 unique participants during both the initial and second monotherapy phases. A logistic regression analysis was performed on the initial monotherapy cohort (n = 103) with complete exposure-response data. Eighty-four participants achieved seizure freedom with a wide range of ethosuximide area under the curves (AUC) ranging from 420 to 2,420 μg·h/mL. AUC exposure estimates for achieving a 50% and 75% probability of seizure freedom were 1,027 and 1,489 μg·h/mL, respectively, whereas the corresponding cumulative frequency of intolerable adverse events was 11% and 16%. Monte Carlo Simulation indicated a daily dose of 40 and 55 mg/kg to achieve 50% and 75% probability of seizure freedom in the overall population, respectively. We identified the need for adjusted mg/kg dosing in different body weight cohorts. This ethosuximide proposed model-informed precision dosing guidance to achieve seizure freedom carries promise to optimize initial monotherapy success for patients with CAE.

Rates of laboratory adverse events by course in paediatric leukaemia ascertained with automated electronic health record extraction: a retrospective cohort study from the Children's Oncology Group

BACKGROUND

Adverse events are often misreported in clinical trials, leading to an incomplete understanding of toxicities. We aimed to test automated laboratory adverse event ascertainment and grading (via the ExtractEHR automated package) to assess its scalability and define adverse event rates for children with acute myeloid leukaemia and acute lymphoblastic leukaemia.

METHODS

For this retrospective cohort study from the Children's Oncology Group (COG), we included patients aged 0-22 years treated for acute myeloid leukaemia or acute lymphoblastic leukaemia at Children's Healthcare of Atlanta (Atlanta, GA, USA) from Jan 1, 2010, to Nov 1, 2018, at the Children's Hospital of Philadelphia (Philadelphia, PA, USA) from Jan 1, 2011, to Dec 31, 2014, and at the Texas Children's Hospital (Houston, TX, USA) from Jan 1, 2011, to Dec 31, 2014. The ExtractEHR automated package acquired, cleaned, and graded laboratory data as per Common Terminology Criteria for Adverse Events (CTCAE) version 5 for 22 commonly evaluated grade 3-4 adverse events (fatal events were not evaluated) with numerically based CTCAE definitions. Descriptive statistics tabulated adverse event frequencies. Adverse events ascertained by ExtractEHR were compared to manually reported adverse events for patients enrolled in two COG trials (AAML1031, NCT01371981; AALL0932, NCT02883049). Analyses were restricted to protocol-defined chemotherapy courses (induction I, induction II, intensification I, intensification II, and intensification III for acute myeloid leukaemia; induction, consolidation, interim maintenance, delayed intensification, and maintenance for acute lymphoblastic leukaemia).

FINDINGS

Laboratory adverse event data from 1077 patients (583 from Children's Healthcare of Atlanta, 200 from the Children's Hospital of Philadelphia, and 294 from the Texas Children's Hospital) who underwent 4611 courses (549 for acute myeloid leukaemia and 4062 for acute lymphoblastic leukaemia) were extracted, processed, and graded. Of the 166 patients with acute myeloid leukaemia, 86 (52%) were female, 80 (48%) were male, 96 (58%) were White, and 132 (80%) were non-Hispanic. Of the 911 patients with acute lymphoblastic leukaemia, 406 (45%) were female, 505 (55%) were male, 596 (65%) were White, and 641 (70%) were non-Hispanic. Patients with acute myeloid leukaemia had the most adverse events during induction I and intensification II. Hypokalaemia (one [17%] of six to 75 [48%] of 156 courses) and alanine aminotransferase (ALT) increased (13 [10%] of 134 to 27 [17%] of 156 courses) were the most prevalent non-haematological adverse events in patients with acute myeloid leukaemia, as identified by ExtractEHR. Patients with acute lymphoblastic leukaemia had the greatest number of adverse events during induction and maintenance (eight adverse events with prevalence ≥10%; induction and maintenance: anaemia, platelet count decreased, white blood cell count decreased, neutrophil count decreased, lymphocyte count decreased, ALT increased, and hypocalcaemia; induction: hypokalaemia; maintenance: aspartate aminotransferase [AST] increased and blood bilirubin increased), as identified by ExtractEHR. 187 (85%) of 220 total comparisons in 22 adverse events in four AAML1031 and six AALL0923 courses were substantially higher with ExtractEHR than COG-reported adverse event rates for adverse events with a prevalence of at least 2%.

INTERPRETATION

ExtractEHR is scalable and accurately defines laboratory adverse event rates for paediatric acute leukaemia; moreover, ExtractEHR seems to detect higher rates of laboratory adverse events than those reported in COG trials. These rates can be used for comparisons between therapies and to counsel patients treated on or off trials about the risks of chemotherapy. ExtractEHR-based adverse event ascertainment can improve reporting of laboratory adverse events in clinical trials.

FUNDING

US National Institutes of Health, St Baldrick's Foundation, and Alex's Lemonade Stand Foundation.

Dose-Adjusted Etoposide, Doxorubicin, and Cyclophosphamide With Vincristine and Prednisone Plus Rituximab Therapy in Children and Adolescents With Primary Mediastinal B-Cell Lymphoma: A Multicenter Phase II Trial

PURPOSE

A dose-adjusted etoposide, doxorubicin, and cyclophosphamide with vincristine and prednisone plus rituximab (DA-EPOCH-R) regimen has been shown to deliver excellent survival for adults with primary mediastinal large B-cell lymphoma (PMLBL) without the use of radiotherapy. No international prospective evaluation of this regimen has previously been reported in children and adolescents.

PATIENTS AND METHODS

We conducted an international single-arm phase II trial involving patients younger than age 18 years with PMLBL who were to receive six courses of DA-EPOCH-R. The primary end point was event-free survival (EFS). Overall survival and toxicity were also assessed. This trial was registered (ClinicalTrials.gov identifier: NCT01516567).

RESULTS

Analyses were based on 46 patients. The median age was 15.4 years (interquartile range: 14-16 years). The median follow-up was 59.0 months (interquartile range: 52.6-69.2 months). Fourteen events were observed (eight relapses or progressions (including three parenchymal CNS relapses), four residual lymphoma, and two second malignancies). The 4-year EFS was 69.6% (95% CI, 55.2 to 80.9), which did not differ from the rate observed historically (P = .59). Seven deaths occurred (six disease-related and one second malignancy). The overall survival was 84.8% (95% CI, 71.8 to 92.4). Twenty-two patients (48%) reached dose levels ≥ 4. Nonhematologic adverse events grade ≥ 3 or cardiac adverse events grade ≥ 2 occurred in 47 of 276 (17%) courses and 30 of 46 patients (65%).

CONCLUSION

DA-EPOCH-R did not improve the EFS compared with a historical control in this first prospective multisite international study of children and adolescents with PMLBL. Further studies are required to determine the optimum therapy for children and adolescents with this lymphoma.

Phase 1/2 Trial of Vorinostat and Radiation and Maintenance Vorinostat in Children with Diffuse Intrinsic Pontine Glioma: A Children's Oncology Group Report

BACKGROUND

A phase 1/2 trial of vorinostat (suberoylanilide hydroxamic acid), an oral histone deacetylase (HDAC) inhibitor, was conducted in children with newly-diagnosed diffuse intrinsic pontine glioma (DIPG) through the Children's Oncology Group (COG) to: 1) determine the recommended phase 2 dose (RP2D) of vorinostat given concurrently with radiation therapy; 2) document the toxicities of continuing vorinostat as maintenance therapy after radiation; and 3) to determine the efficacy of this regimen by comparing the risk of progression or death with an historical model from past COG trials.

METHODS

Vorinostat was given once daily, Monday through Friday, during radiation therapy (54 Gy in 30 fractions), and then continued at 230 mg/m 2 daily for a maximum of twelve 28-day cycles.

RESULTS

Twelve patients enrolled on the phase 1 study; the RP2D of vorinostat given concurrently with radiation was 230 mg/m 2/day, Monday through Friday weekly. The six patients enrolled at the RP2D and an additional 64 patients enrolled onto the phase 2 study contributed to the efficacy assessment. Although vorinostat was well-tolerated, did not interrupt radiation therapy, and was permanently discontinued in only 8.6% of patients due to toxicities, risk for EFS-event was not significantly reduced compared with the target risk derived from historical COG data (p = 0.32; 1-sided). The 1-year EFS was 5.85% (95% CI 1.89 - 13.1%) and 1-year OS was 39.2% (27.8 - 50.5%).

CONCLUSIONS

Vorinostat given concurrently with radiation followed by vorinostat monotherapy was well tolerated in children with newly-diagnosed DIPG but failed to improve outcome.

Abstract 631: Germline cancer predisposition results from the National Cancer Institute - Children's Oncology Group (NCI-COG) Pediatric MATCH Trial

Background: Although genomic changes identified by clinical tumor sequencing may be present in the germline, precision oncology trials have generally not incorporated germline testing and reporting. We describe our experience with clinical reporting of matched tumor and germline results from the NCI-COG Pediatric Molecular Analysis for Therapy Choice (MATCH) trial (NCT03155620).

Design/Method: Patients age 1 to 21 years old with treatment-refractory solid tumors, non-Hodgkin lymphomas, or histiocytic disorders were eligible. DNA and RNA extracted from FFPE tumors were sequenced using Oncomine Assay v.3 with reporting of potentially actionable fusions, amplifications, and mutations, including loss of function variants in tumor suppressor genes. Germline reporting focused on 36 genes from the same DNA panel that convey adult or pediatric cancer susceptibility but does not include all cancer susceptibility genes (e.g. APC, DICER1). Deletions and splice site variants were not reported.

Results: As of June 2020, 1009 patients had been enrolled from 132 COG sites, with tumor and germline testing complete for 868 patients to date. Overall, 62 (7.1%) germline reports included a pathogenic or likely pathogenic germline variant (termed germline findings) in 18 cancer susceptibility genes. This frequency was similar in patients with solid tumors (46/633, 7.3%), CNS tumors (14/204, 6.9%), and lymphomas/histiocytoses (2/31, 6.5%). Variant(s) of potential germline significance were identified in 25% of tumor reports; of these, 74% (163/221) had no germline findings. The proportion of germline findings for genes with >10 reported tumor variants varied: 32% (7/22) in NF1, 25% (3/12) in RB1, 16% (17/108) in TP53 and 0% in ALK (0/21) and PTEN (0/12). Of note, 82% (14/17) of tumor variants in breast cancer susceptibility genes (BRCA1/2, CHEK2 and PALB2) had germline findings. On study intake forms, 25% of patients with germline findings had a “known genetic disease” reported. Oncologists caring for patients with a germline finding were then queried about prior knowledge of a genetic diagnosis. Of 24 respondents, 13 (54%) reported no prior molecular diagnosis of the identified condition.

Conclusions: Coordinated germline and tumor testing revealed clinically relevant cancer susceptibility variants across a spectrum of genes in 7% of pediatric patients with treatment-refractory cancers. This is likely an underestimate of germline findings given test limitations. The parallel tumor/normal reporting approach minimized the need for targeted reflex genetic testing in 19% of study participants and provided new information on cancer susceptibility in germline positive patients to half of the responding oncologists. The NCI-COG Pediatric MATCH trial reporting process can serve as a model for precision oncology trials and clinical tumor profiling.

Citation Format: Sarah Scollon, Sharon E. Plon, Steven Joffe, Jaclyn A. Biegel, Shashikant Kulkarni, George Miles, David Patton, Brent Coffey, Paul M. Williams, Gregory J. Tsongalis, Mark J. Routbort, Julie M. Gastier-Foster, Lauren Saguilig, Jin Piao, Todd A. Alonzo, Katherine A. Janeway, Peter C. Adamson, Margaret Mooney, James V. Tricoli, Nita L. Seibel, Donald W. Parsons. Germline cancer predisposition results from the National Cancer Institute - Children's Oncology Group (NCI-COG) Pediatric MATCH Trial [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 631.

Activity of Crizotinib in Patients with ALK-Aberrant Relapsed/Refractory Neuroblastoma: A Children's Oncology Group Study (ADVL0912)

PURPOSE

Anaplastic lymphoma kinase (ALK) aberrations are a promising target for patients with neuroblastoma. We assessed the activity of first-generation ALK inhibitor crizotinib in patients with no known curative treatments and whose tumors harbored an activating ALK alteration.

PATIENTS AND METHODS

Twenty patients with relapsed/refractory ALK-positive neuroblastoma received crizotinib at the recommended phase II dose of 280 mg/m²/dose. A Simon two-stage design was used to evaluate the antitumor activity of crizotinib monotherapy. Response evaluation occurred after cycles 1, 3, 5, 7, and then every 3 cycles. Correlation of ALK status and response was a secondary aim of the study.

RESULTS

The objective response rate for patients with neuroblastoma was 15% [95% confidence interval (CI): 3.3%-34.3%]: two with partial responses and 1 with a complete response. All three patients had a somatic ALK Arg1275Gln mutation, the most common ALK hotspot mutation observed in neuroblastoma and the only mutation predicted to be sensitive to ALK inhibition with crizotinib. Two patients had prolonged stable disease (10 and 13 cycles, respectively); both harbored an ALK Arg1275Gln mutation. Three patients with ALK Phe1174Leu mutations progressed during cycle 1 of therapy, and one patient with an ALK Phe1174Val received three cycles before disease progression. The two patients with ALK amplification had no response. The most common adverse event was a decrease in neutrophil count.

CONCLUSIONS

Despite limited activity seen in this trial, we conclude that this is more likely due to an inability to reach the higher concentrations of crizotinib needed to overcome the competing ATP affinity.See related commentary by Schulte and Eggert, p. 3507.

Safety, tolerability and pharmacokinetics of crizotinib in combination with cytotoxic chemotherapy for pediatric patients with refractory solid tumors or anaplastic large cell lymphoma (ALCL): a Children's Oncology Group phase 1 consortium study (ADVL1212)

PURPOSE

This phase 1 study aimed to determine the safety, tolerability and recommended phase 2 dose (RP2D) of crizotinib in combination with cytotoxic chemotherapy for children with refractory solid tumors and ALCL.

METHODS

Pediatric patients with treatment refractory solid tumors or ALCL were eligible. Using a 3 + 3 design, crizotinib was escalated in three dose levels: 165, 215, or 280 mg/m²/dose BID. In Part A, patients received crizotinib oral solution (OS) in combination with topotecan and cyclophosphamide (topo/cyclo); in Part B, crizotinib OS was administered with vincristine and doxorubicin (vcr/dox). In Parts C and D, patients received topo/cyclo in combination with either crizotinib-formulated capsules (FC) or microspheres (cMS), respectively. Crizotinib pharmacokinetic evaluation was required.

RESULTS

Forty-four eligible patients were enrolled, 39 were evaluable for toxicity. Parts A and B were terminated due to concerns regarding palatability and tolerability of the OS. In Part C, crizotinib, FC 215 mg/m²/dose BID, in combination with topo/cyclo was tolerated. In Part D, the maximum tolerated dose (MTD) was exceeded at 165 mg/m²/dose of crizotinib cMS. Pharmacokinetics of crizotinib in combination with chemotherapy was similar to single-agent crizotinib and exposures were not formulation dependent.

CONCLUSIONS

The RP2D of crizotinib FCs in combination with cyclophosphamide and topotecan was 215 mg/m²/dose BID. The oral solution of crizotinib was not palatable in this patient population. Crizotinib cMS was palatable; however, patients experienced increased toxicity that was not explained by the relative bioavailability or exposure and warrants further investigation.

CLINICAL TRIAL REGISTRY

The trial is registered as NCT01606878 at Clinicaltrials.gov.

Paediatric Strategy Forum for medicinal product development of epigenetic modifiers for children: ACCELERATE in collaboration with the European Medicines Agency with participation of the Food and Drug Administration

The fifth multistakeholder Paediatric Strategy Forum focussed on epigenetic modifier therapies for children and adolescents with cancer. As most mutations in paediatric malignancies influence chromatin-associated proteins or transcription and paediatric cancers are driven by developmental gene expression programs, targeting epigenetic mechanisms is predicted to be a very important therapeutic approach in paediatric cancer. The Research to Accelerate Cures and Equity (RACE) for Children Act FDARA amendments to section 505B of the FD&C Act was implemented in August 2020, and as there are many epigenetic targets on the FDA Paediatric Molecular Targets List, clinical evaluation of epigenetic modifiers in paediatric cancers should be considered early in drug development. Companies are also required to submit to the EMA paediatric investigation plans aiming to ensure that the necessary data to support the authorisation of a medicine for children in EU are of high quality and ethically researched. The specific aims of the forum were i) to identify epigenetic targets or mechanisms of action associated with epigenetic modification relevant to paediatric cancers and ii) to define the landscape for paediatric drug development of epigenetic modifier therapies. DNA methyltransferase inhibitors/hypomethylating agents and histone deacetylase inhibitors were largely excluded from discussion as the aim was to discuss those targets for which therapeutic agents are currently in early paediatric and adult development. Epigenetics is an evolving field and could be highly relevant to many paediatric cancers; the biology is multifaceted and new targets are frequently emerging. Targeting epigenetic mechanisms in paediatric malignancy has in most circumstances yet to reach or extend beyond clinical proof of concept, as many targets do not yet have available investigational drugs developed. Eight classes of medicinal products were discussed and prioritised based on the existing level of science to support early evaluation in children: inhibitors of menin, DOT1L, EZH2, EED, BET, PRMT5 and LSD1 and a retinoic acid receptor alpha agonist. Menin inhibitors should be moved rapidly into paediatric development, in view of their biological rationale, strong preclinical activity and ability to fulfil an unmet clinical need. A combination approach is critical for successful utilisation of any epigenetic modifiers (e.g. EZH2 and EED) and exploration of the optimum combination(s) should be supported by preclinical research and, where possible, molecular biomarker validation in advance of clinical translation. A follow-up multistakeholder meeting focussing on BET inhibitors will be held to define how to prioritise the multiple compounds in clinical development that could be evaluated in children with cancer. As epigenetic modifiers are relatively early in development in paediatrics, there is a clear opportunity to shape the landscape of therapies targeting the epigenome in order that efficient and optimum plans for their evaluation in children and adolescents are developed in a timely manner.

Pediatric cancer research: Surviving COVID-19

A diverse panel of pediatric cancer advocates and experts, whose collective experience spans the continuum of international academic medicine, industry, government research, and cancer advocacy, recently discussed challenges for pediatric cancer research in the context of coronavirus disease 2019 (COVID-19). Specifically, this special report addresses the following focus areas: (a) the critical role that translational research has played in transforming pediatric cancer outcomes; (b) the current and potential future impact of COVID-19 on pediatric cancer research; (c) target areas of COVID-19 research that may have application in immunity, oncogenesis, and therapeutic discovery; and (d) future considerations and directions in maintaining pediatric cancer research during and after COVID-19.

Paediatric Strategy Forum for medicinal product development for acute myeloid leukaemia in children and adolescents: ACCELERATE in collaboration with the European Medicines Agency with participation of the Food and Drug Administration

Purpose:

The current standard-of-care for front-line therapy for acute myeloid leukaemia (AML) results in short-term and long-term toxicity, but still approximately 40% of children relapse. Therefore, there is a major need to accelerate the evaluation of innovative medicines, yet drug development continues to be adult-focused. Furthermore, the large number of competing agents in rare patient populations requires coordinated prioritisation, within the global regulatory framework and cooperative group initiatives.

Methods:

The fourth multi-stakeholder Paediatric Strategy Forum focused on AML in children and adolescents.

Results:

CD123 is a high priority target and the paediatric development should be accelerated as a proof-of-concept. Efforts must be coordinated, however, as there are a limited number of studies that can be delivered. Studies of FLT3 inhibitors in agreed paediatric investigation plans present challenges to be completed because they require enrolment of a larger number of patients than actually exist. A consensus was developed by industry and academia of optimised clinical trials. For AML with rare mutations that are more frequent in adolescents than in children, adult trials should enrol adolescents and when scientifically justified, efficacy data could be extrapolated. Methodologies and definitions of minimal residual disease need to be standardised internationally and validated as a new response criterion. Industry supported, academic sponsored platform trials could identify products to be further developed. The Leukaemia and Lymphoma Society PedAL/EUpAL initiative has the potential to be a major advance in the field.

Conclusion:

These initiatives continue to accelerate drug development for children with AML and ultimately improve clinical outcomes.

Rituximab for High-Risk, Mature B-Cell Non-Hodgkin's Lymphoma in Children

BACKGROUND

Rituximab added to chemotherapy prolongs survival among adults with B-cell cancer. Data on its efficacy and safety in children with high-grade, mature B-cell non-Hodgkin's lymphoma are limited.

METHODS

We conducted an open-label, international, randomized, phase 3 trial involving patients younger than 18 years of age with high-risk, mature B-cell non-Hodgkin's lymphoma (stage III with an elevated lactate dehydrogenase level or stage IV) or acute leukemia to compare the addition of six doses of rituximab to standard lymphomes malins B (LMB) chemotherapy with standard LMB chemotherapy alone. The primary end point was event-free survival. Overall survival and toxic effects were also assessed.

RESULTS

Analyses were based on 328 patients who underwent randomization (164 patients per group); 85.7% of the patients had Burkitt's lymphoma. The median follow-up was 39.9 months. Events were observed in 10 patients in the rituximab-chemotherapy group and in 28 in the chemotherapy group. Event-free survival at 3 years was 93.9% (95% confidence interval [CI], 89.1 to 96.7) in the rituximab-chemotherapy group and 82.3% (95% CI, 75.7 to 87.5) in the chemotherapy group (hazard ratio for primary refractory disease or first occurrence of progression, relapse after response, death from any cause, or second cancer, 0.32; 95% CI, 0.15 to 0.66; one-sided P = 0.00096, which reached the significance level required for this analysis). Eight patients in the rituximab-chemotherapy group died (4 deaths were disease-related, 3 were treatment-related, and 1 was from a second cancer), as did 20 in the chemotherapy group (17 deaths were disease-related, and 3 were treatment-related) (hazard ratio, 0.36; 95% CI, 0.16 to 0.82). The incidence of acute adverse events of grade 4 or higher after prephase treatment was 33.3% in the rituximab-chemotherapy group and 24.2% in the chemotherapy group (P = 0.07); events were related mainly to febrile neutropenia and infection. Approximately twice as many patients in the rituximab-chemotherapy group as in the chemotherapy group had a low IgG level 1 year after trial inclusion.

CONCLUSIONS

Rituximab added to standard LMB chemotherapy markedly prolonged event-free survival and overall survival among children and adolescents with high-grade, high-risk, mature B-cell non-Hodgkin's lymphoma and was associated with a higher incidence of hypogammaglobulinemia and, potentially, more episodes of infection. (Funded by the Clinical Research Hospital Program of the French Ministry of Health and others; ClinicalTrials.gov number, NCT01516580.).

A phase II/III study of JZP-458 in patients with acute lymphoblastic leukemia (ALL)/lymphoblastic lymphoma (LBL) who are hypersensitive to E. coli-derived asparaginases

TPS7568

Background: L-asparaginase is an important component of ALL therapy and the inability to receive asparaginase secondary to hypersensitivity has been associated with poor patient (pt) outcomes. Alternative options for pts after hypersensitivity reactions are needed. JZP-458 is a recombinant Erwinia asparaginase produced using a novel Pseudomonas fluorescens expression platform that yields an enzyme with no immunologic cross-reactivity to E. coli–derived asparaginases. In a phase 1 study, JZP-458 was well tolerated and maintained adequate (≥0.1 IU/mL) serum asparaginase activity (SAA), a surrogate marker for asparagine depletion, for up to 72 hrs in healthy adults. Methods: This is a pivotal, open-label, multicenter, dose confirmation, and pharmacokinetic (PK) study (NCT04145531) of JZP-458 in pts with ALL/LBL who develop hypersensitivity reactions to a long-acting E. coli–derived asparaginase and have ≥1 course of asparaginase remaining in their treatment plan (Table); 6 doses of JZP-458 will be substituted for each remaining course. Treatment duration will depend on the number of asparaginase courses remaining in the treatment plan. The study has 2 sequential parts: Part A will determine the dose of intramuscular (IM) JZP-458 and confirm safety/efficacy; Part B will explore the dose/schedule of intravenous (IV) JZP-458. Blood samples will be collected to determine SAA levels and pts will be monitored for adverse events. Immunogenicity of JZP-458 will be assessed. Primary objectives are to determine (1) the efficacy of IM JZP-458 measured by the last 72-hr nadir SAA (NSAA) level (≥0.1 IU/mL) during the first treatment course, and (2) the safety/tolerability of IM JZP-458. Secondary objectives are to determine the efficacy (measured by the last 48-hr NSAA level [≥0.1 IU/mL] and the last 48- and 72-hr NSAA levels [≥0.4 IU/mL]), PK, and immunogenicity of IM JZP-458. Exploratory objectives include efficacy, safety, PK, and immunogenicity of IV JZP-458. The trial is active and enrolling. Clinical trial information: NCT04145531 . [Table: see text]

New Business Models to Accelerate Innovation in Pediatric Oncology Therapeutics: A Review

Importance

Few patient populations are as helpless and in need of advocacy as children with cancer. Pharmaceutical companies have historically faced significant financial disincentives to pursue pediatric oncology therapeutics, including low incidence, high costs of conducting pediatric trials, and a lack of funding for early-stage research.

Observations

Review of published studies of pediatric oncology research and the cost of drug development, as well as clinical trials of pediatric oncology therapeutics at ClinicalTrials.gov, identified 77 potential drug development projects to be included in a hypothetical portfolio. The returns of this portfolio were simulated so as to compute the financial returns and risk. Simulated business strategies include combining projects at different clinical phases of development, obtaining partial funding from philanthropic grants, and obtaining government guarantees to reduce risk. The purely private-sector portfolio exhibited expected returns ranging from -24.2% to 10.2%, depending on the model variables assumed. This finding suggests significant financial disincentives for pursuing pediatric oncology therapeutics and implies that financial support from the public and philanthropic sectors is essential. Phase diversification increases the likelihood of a successful drug and yielded expected returns of -5.3% to 50.1%. Standard philanthropic grants had a marginal association with expected returns, and government guarantees had a greater association by reducing downside exposure. An assessment of a proposed venture philanthropy fund demonstrated stronger performance than the purely private-sector-funded portfolio or those with traditional amounts of philanthropic support.

Clinical Relevance

A combination of financial and business strategies has the potential to maximize expected return while eliminating some downside risk-in certain cases enabling expected returns as high as 50.1%-that can overcome current financial disincentives and accelerate the development of pediatric oncology therapeutics.

Insights into pediatric rhabdomyosarcoma research: Challenges and goals

Overall survival rates for pediatric patients with high-risk or relapsed rhabdomyosarcoma (RMS) have not improved significantly since the 1980s. Recent studies have identified a number of targetable vulnerabilities in RMS, but these discoveries have infrequently translated into clinical trials. We propose streamlining the process by which agents are selected for clinical evaluation in RMS. We believe that strong consideration should be given to the development of combination therapies that add biologically targeted agents to conventional cytotoxic drugs. One example of this type of combination is the addition of the WEE1 inhibitor AZD1775 to the conventional cytotoxic chemotherapeutics, vincristine and irinotecan.

Unintended consequences of evolution of the Common Terminology Criteria for Adverse Events

BACKGROUND

Adverse events (AEs) on Children's Oncology Group (COG) trials are reported manually by clinical research assistants (CRAs). The Common Terminology Criteria for Adverse Events (CTCAE) was developed to provide standardized definitions for identifying and grading AEs. The CTCAE has expanded significantly over its five versions, but the impact of CTCAE definitional changes has not been examined.

PROCEDURE

This study compared AE number and ascertainment among the first four CTCAE versions using a case vignette. Each CTCAE version was used to create a list of AEs and grades by two separate CRAs.

RESULTS

The CTCAE expanded from 9 categories and 49 AEs in v1.0 to 26 categories and 790 AEs in v4.0. CRAs independently selected different approaches to AE ascertainment-comprehensive and parsimonious. The number of AEs identified in the parsimonious approach was stable with 10-14 in each CTC version. The comprehensive approach identified 9, 20, 29, and 37 AEs in CTC versions 1.0, 2.0, 3.0, and 4.0, respectively. Only approximately 65% of AEs were conclusively graded in versions 2.0 to 4.0 using the comprehensive approach.

CONCLUSIONS

CTCAE has increased in complexity. Although this increased complexity allows for more granular AE reporting, these data demonstrate potential unintended negative consequences of increasing CTC AE complexity, including the risk of varying approaches to AE capture. A comprehensive evaluation of CTC AE definitions and CRA reporting practices across COG institutions and AEs are needed to improve the accuracy and efficiency of AE reporting.

Fundamental problems with pediatric adaptive dosing of carboplatin using nuclear-medicine-based estimates of renal function

BACKGROUND

Carboplatin is often adaptively dosed based on glomerular filtration rate (GFR), usually estimated by nuclear medicine tests. At least five pediatric adaptive dosing formulas have been developed. In an effort to standardize dosing in Children's Oncology Group protocols, we explored methodologic variation in GFR estimation and adaptive-dosing formula performance.

PROCEDURE

Nuclear medicine GFR data from published series of ≥100 children with cancer were compared. Data from patients for whom body surface area, weight, GFR, and tracer half-life were available were used to compare formulas.

RESULTS

Differences in methods used to estimate GFR in children with cancer resulted in highly variable population results, with median GFRs ranging from 96 to 150 mL/min/1.73m² . The choice of adaptive formula had a major impact on calculated dose. When targeting an area under the curve of 7.9 mg/mL • min, the median difference between the formula yielding the lowest and highest carboplatin dose for individual subjects was 289 (range 96-1 737) mg/m² .

CONCLUSIONS

Wide variation in GFR obtained with nuclear-medicine-based tests in children with cancer primarily results from systematic methodologic errors. Formulas for calculating carboplatin dose produce additional and substantial variation that may place children with cancer at unnecessary risk for excessive toxicity or underdosing. These findings indicate a need for the development of a uniform, validated method for GFR determination in children that should be utilized in all centers. Currently, adaptive dosing of carboplatin based on GFR has serious limitations and in most clinical settings should arguably not be used in place of body-surface-area-based dosing.

Identification of targetable molecular alterations in the NCI-COG Pediatric MATCH trial

10011

Background: The screening protocol for the NCI-Children’s Oncology Group (COG) Pediatric Molecular Analysis for Therapy Choice (MATCH) trial detects tumor alterations that are used to assign patients with treatment-refractory or recurrent cancers to phase 2 treatment arms of molecularly-targeted therapies. Methods: Patients age 1 to 21 years old with treatment-refractory or recurrent solid tumors, non-Hodgkin lymphomas, or histiocytic disorders treated at U.S. based COG sites are eligible. DNA and RNA extracted from FFPE tumor samples are sequenced using an Oncomine cancer gene panel for detection of mutations, amplifications, and fusions. Loss of SMARCB1, SMARCA4, and PTEN expression is detected by immunohistochemistry. Lists of actionable mutations (aMOIs) based upon available clinical and pre-clinical data are used a priori to determine eligibility for treatment arms. Results: Between 7/24/17 and 12/31/18, 422 patients with a median age of 13 years (range 1-21) were enrolled from 93 COG sites. Solid tumors comprised 71% (n = 300) of diagnoses, CNS tumors 24% (n = 101) and lymphomas/histiocytoses 5% (n = 21). A tumor sample was submitted for 390 patients, sequencing was attempted for 370 (95%), and results were confirmed for 357 (92%). Median turn-around time was 15 days. An aMOI for at least one of the 10 current treatment arms was identified in 112 patients (29%, 95% CI 24%-33%); 95 patients (24%, 95% CI 20%-29%) were assigned to a treatment arm with 39 patients (10%, 95% CI 7%-13%) enrolled to date. The aMOI rate was similar in patients less than 12 years of age (35%) compared to patients 12 years and older (25%). Actionable MAPK pathway alterations were found in 11% of patients (n = 41), most often HRAS/ KRAS/ NRAS mutations (n = 16), BRAF mutations or fusions (n = 14), or NF1 mutations (n = 11). Other genes with recurrent aMOIs included SMARCB1 (n = 14), ALK (n = 8), CDK4 (n = 8), PIK3CA (n = 7), PTEN (n = 7), FGFR1 (n = 5), and BRCA1/BRCA2 (n = 5). Conclusions: Approximately one-quarter of patients with tumor submitted for Pediatric MATCH screening have been assigned to an investigational therapy, facilitating the evaluation of molecularly-targeted agents in biomarker-positive pediatric cohorts through a collaborative nationwide study. Clinical trial information: NCT03155620.

The Children's Oncology Group: Organizational Structure, Membership, and Institutional Characteristics

BACKGROUND

The Children's Oncology Group (COG) is the only organization within the National Cancer Institute's National Clinical Trials Network dedicated exclusively to pediatric cancer research. The purpose of this article is to provide an overview of COG's organizational structure, to characterize its institutional and individual membership, and to summarize enrollments onto COG clinical trials.

METHOD

Data from 2013 to 2015 were compiled from sources internal (Network Operations, Statistics and Data Center, Chair's Office) and external (American Hospital Association, American Nurses Credentialing Center) to COG, to present a comprehensive overview of COG's structure, individual and institutional membership, and group operations.

RESULTS

In 2016, COG comprised 8,785 individuals from 223 member institutions, across seven countries. An average of 9,661 new patients were registered with COG per year over the most recent (2013-2015) 3-year period. Over the same 3-year time frame, there were an average of 16,836 enrollments onto therapeutic (i.e., treatment) and nontherapeutic (e.g., epidemiology, survivorship, biology) trials per year.

CONCLUSIONS

COG institutions have diverse characteristics related to size, geographical location, and infrastructure. Individual membership also reflects diversity with representation from over 28 disciplines and groups. The diversity of COG institutions and individual members allows for unique perspectives and contributions to science unified under a common goal to enroll children/adolescents onto clinical trials. COG's collaborative, multidisciplinary approach to science functions to support the development of research that seeks to continually improve outcomes for children and adolescents with cancer.

Early clinical observations on the use of imatinib mesylate in FOP: A report of seven cases

BACKGROUND

Fibrodysplasia ossificans progressiva (FOP) is an ultrarare genetic disorder of progressive, disabling heterotopic ossification (HO) for which there is presently no definitive treatment. Research studies have identified multiple potential targets for therapy in FOP, and novel drug candidates are being developed for testing in clinical trials. A complementary approach seeks to identify approved drugs that could be re-purposed for off-label use against defined targets in FOP. One such drug is imatinib mesylate, a tyrosine kinase inhibitor originally developed for use in patients with chronic myeloid leukemia (CML). Imatinib has the desirable effect of attacking multiple targets involved in the early hypoxic and inflammatory stages of FOP flare-ups, including HIF1-α, PDGFRα, c-KIT, and multiple MAP kinases.

RESULTS

Based on compelling biologic rationale, strong preclinical data, and a favorable safety profile, imatinib has been prescribed on an off-label basis in a non-trial setting in seven children with continuous FOP flare-ups, predominantly in the axial regions, and which were not responsive to standard-of-care regimens. Anecdotal reports in these seven isolated cases document that the medication was well-tolerated with a ubiquitous reported decrease in the intensity of flare-ups in the six children who took the medication.

CONCLUSIONS

These early clinical observations support the implementation of clinical trials in children with uncontrolled FOP flare-ups to determine if imatinib may ameliorate symptoms or alter the natural history of this debilitating and life-threatening disease.

Outcome of pediatric patients with acute lymphoblastic leukemia/lymphoblastic lymphoma with hypersensitivity to pegaspargase treated with PEGylated Erwinia asparaginase, pegcrisantaspase: A report from the Children's Oncology Group

BACKGROUND

Erwinia asparaginase is a Food and Drug Administration approved agent for the treatment of acute lymphoblastic leukemia (ALL) for patients who develop hypersensitivity to Escherichia coli derived asparaginases. Erwinia asparaginase is efficacious, but has a short half-life, requiring six doses to replace one dose of the most commonly used first-line asparaginase, pegaspargase, a polyethylene glycol (PEG) conjugated E. coli asparaginase. Pegcristantaspase, a recombinant PEGylated Erwinia asparaginase with improved pharmacokinetics, was developed for patients with hypersensitivity to pegaspargase. Here, we report a series of patients treated on a pediatric phase 2 trial of pegcrisantaspase.

PROCEDURE

Pediatric patients with ALL or lymphoblastic lymphoma and hypersensitivity to pegaspargase enrolled on Children's Oncology Group trial AALL1421 (Jazz 13-011) and received intravenous pegcrisantaspase. Serum asparaginase activity (SAA) was monitored before and after dosing; immunogenicity assays were performed for antiasparaginase and anti-PEG antibodies and complement activation was evaluated.

RESULTS

Three of the four treated patients experienced hypersensitivity to pegcrisantaspase manifested as clinical hypersensitivity reactions or rapid clearance of SAA. Immunogenicity assays demonstrated the presence of anti-PEG immunoglobulin G antibodies in all three hypersensitive patients, indicating a PEG-mediated immune response.

CONCLUSIONS

This small series of patients, nonetheless, provides data, suggesting preexisting immunogenicity against the PEG moiety of pegaspargase and poses the question as to whether PEGylation may be an effective strategy to optimize Erwinia asparaginase administration. Further study of larger cohorts is needed to determine the incidence of preexisting antibodies against PEG-mediated hypersensitivity to pegaspargase.

Dosing anticancer drugs in infants: Current approach and recommendations from the Children's Oncology Group's Chemotherapy Standardization Task Force

An analysis of dose modifications for infants in 29 Children's Oncology Group protocols across 10 cancer types revealed 11 sets of criteria defining the infant population using age, weight, body surface area (BSA), or a combination of these parameters and eight dose modification methods. A new method of dosing anticancer drugs in infants was developed based on the rationale that prior modifications were implemented to reduce toxicity, which is not cancer-specific. The new method uses BSA dose banding in dosing tables for infants and children with a BSA <0.6 m² and gradually transitions from body weight based to BSA-based dosing.

Target and Agent Prioritization for the Children's Oncology Group-National Cancer Institute Pediatric MATCH Trial

Over the past decades, outcomes for children with cancer have improved dramatically through serial clinical trials based in large measure on dose intensification of cytotoxic chemotherapy for children with high-risk malignancies. Progress made through such dose intensification, in general, is no longer yielding further improvements in outcome. With the revolution in sequencing technologies and rapid development of drugs that block specific proteins and pathways, there is now an opportunity to improve outcomes for pediatric cancer patients through mutation-based targeted therapeutic strategies. The Children's Oncology Group (COG), in partnership with the National Cancer Institute (NCI), is planning a trial entitled the COG-NCI Pediatric Molecular Analysis for Therapeutic Choice (Pediatric MATCH) protocol utilizing an umbrella design. This protocol will have centralized infrastructure and will consist of a biomarker profiling protocol and multiple single-arm phase II trials of targeted therapies. Pediatric patients with recurrent or refractory solid tumors, lymphomas, or histiocytoses with measurable disease will be eligible. The Pediatric MATCH Target and Agent Prioritization (TAP) committee includes membership representing COG disease committees, the Food and Drug Administration, and the NCI. The TAP Committee systematically reviewed target and agent pairs for inclusion in the Pediatric MATCH trial. Fifteen drug-target pairs were reviewed by the TAP Committee, with seven recommended for further development as initial arms of the Pediatric MATCH trial. The current evidence for availability, efficacy, and safety of targeted agents in children for each class of mutation considered for inclusion in the Pediatric MATCH trial is discussed in this review.

Second monotherapy in childhood absence epilepsy

OBJECTIVE

To determine optimal second monotherapy for children with childhood absence epilepsy (CAE) experiencing initial treatment failure.

METHODS

Children with CAE experiencing treatment failure during the double-blind phase of a randomized controlled trial comparing ethosuximide, valproic acid, and lamotrigine were randomized to open-label second monotherapy with one of the 2 other study therapies. Primary study outcome was freedom from failure proportion at week 16-20 and month 12 visits after randomization. Secondary study outcome was percentage of participants experiencing attentional dysfunction at these visits.

RESULTS

A total of 208 children were enrolled, randomized, and received second therapy. At both week 16-20 visit and month 12 visit, ethosuximide's (63%, 57%) and valproic acid's (65%, 49%) freedom from failure proportions were similar to each other and higher than lamotrigine's (45%, 36%, p = 0.051 and p = 0.062). At both time points, ethosuximide and valproic acid had superior seizure control compared to lamotrigine (p < 0.0001). At both the week 16-20 and month 12 visits, attentional dysfunction was numerically more common with valproic acid than with ethosuximide or lamotrigine. For each medication, second monotherapy freedom from failure proportions demonstrated noninferiority to initial monotherapy freedom from failure proportions.

CONCLUSIONS

As second monotherapy, ethosuximide and valproic acid, demonstrated higher freedom from failure proportions and greater efficacy than lamotrigine; valproic acid was associated with more attentional dysfunction. Ethosuximide is the optimal second monotherapy for children with CAE not responding to initial therapy with other medications.

CLINICALTRIALSGOV IDENTIFIER

NCT00088452.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that for children with CAE experiencing initial treatment failure, second monotherapy with ethosuximide or valproic acid is superior to lamotrigine.

Current state of pediatric sarcoma biology and opportunities for future discovery: A report from the sarcoma translational research workshop

Sarcomas are a rare subgroup of pediatric cancers comprised of a variety of bone and soft-tissue tumors. While significant advances have been made in improving outcomes of patients with localized pediatric sarcomas since the addition of systemic chemotherapy to local control many decades ago, outcomes for patients with metastatic and relapsed sarcoma remain poor with few novel therapeutics identified to date. With the advent of new technologies to study cancer genomes, transcriptomes and epigenomes, our understanding of sarcoma biology has improved tremendously in a relatively short period of time. However, much remains to be accomplished in this arena especially with regard to translating all of this new knowledge to the bedside. To this end, a meeting was convened in Philadelphia, PA, on April 18, 2015 sponsored by the QuadW foundation, Children's Oncology Group and CureSearch for Children's Cancer that brought together sarcoma clinicians and scientists from North America to review the current state of pediatric sarcoma biology and ongoing/planned genomics based clinical trials in an effort to identify and bridge knowledge gaps that continue to exist at present. At the conclusion of the workshop, three key objectives that would significantly further our understanding of sarcoma were identified and a proposal was put forward to develop an all-encompassing pediatric sarcoma biology protocol that would address these specific needs. This review summarizes the proceedings of the workshop.

Accuracy of Adverse Event Ascertainment in Clinical Trials for Pediatric Acute Myeloid Leukemia

PURPOSE

Reporting of adverse events (AEs) in clinical trials is critical to understanding treatment safety, but data on AE accuracy are limited. This study sought to determine the accuracy of AE reporting for pediatric acute myeloid leukemia clinical trials and to test whether an external electronic data source can improve reporting.

METHODS

Reported AEs were evaluated on two trials, Children's Oncology Group AAML03P1 and AAML0531 arm B, with identical chemotherapy regimens but with different toxicity reporting requirements. Chart review for 12 AEs for patients enrolled in AAML0531 at 14 hospitals was the gold standard. The sensitivity and positive predictive values (PPV) of the AAML0531 AE report and AEs detected by review of Pediatric Health Information System (PHIS) billing and microbiology data were compared with chart data.

RESULTS

Select AE rates from AAML03P1 and AAML0531 arm B differed significantly and correlated with the targeted toxicities of each trial. Chart abstraction was performed on 204 patients (758 courses) on AAML0531. AE report sensitivity was < 50% for eight AEs, but PPV was > 75% for six AEs. AE reports for viridans group streptococcal bacteremia, a targeted toxicity on AAML0531, had a sensitivity of 78.3% and PPV of 98.1%. PHIS billing data had higher sensitivity (> 50% for nine AEs), but lower PPV (< 75% for 10 AEs). Viridans group streptococcal detection using PHIS microbiology data had high sensitivity (92.3%) and PPV (97.3%).

CONCLUSION

The current system of AE reporting for cooperative oncology group clinical trials in pediatric acute myeloid leukemia underestimates AE rates. The high sensitivity and PPV of PHIS microbiology data suggest that using external data sources may improve the accuracy of AE reporting.

Comparison of in-patient costs for children treated on the AAML0531 clinical trial: A report from the Children's Oncology Group

BACKGROUND

A better understanding of drivers of treatment costs may help identify effective cost containment strategies and prioritize resources. We aimed to develop a method for estimating inpatient costs for pediatric patients with acute myeloid leukemia (AML) enrolled on NCI-funded Phase III trials, compare costs between AAML0531 treatment arms (standard chemotherapy ± gemtuzumab ozogamicin (GMTZ)), and evaluate primary drivers of costs for newly diagnosed pediatric AML.

PROCEDURE

Patients from the AAML0531 trial were matched on hospital, sex, and dates of birth and diagnosis to the Pediatric Health Information Systems (PHIS) database to obtain daily billing data. Inpatient treatment costs were calculated as adjusted charges multiplied by hospital-specific cost-to-charge ratios. Generalized linear models were used to compare costs between treatment arms and courses, and by patient characteristics.

RESULTS

Inpatient costs did not differ by randomized treatment arm. Costs varied by course with stem cell transplant being most expensive, followed by Intensification II (cytarabine/mitoxantrone) and Induction I (cytarabine/daunorubicin/etoposide). Room/board and pharmacy were the largest contributors to inpatient treatment cost, representing 74% of the total cost. Higher AML risk group (P = 0.0003) and older age (P < 0.0001) were associated with significantly higher daily inpatient cost.

CONCLUSIONS

Costs from external data sources can be successfully integrated into NCI-funded Phase III clinical trials. Inpatient treatment costs did not differ by GMTZ exposure but varied by chemotherapy course. Variation in cost by course was driven by differences in duration of hospitalization through room/board charges as well as increased clinical and pharmacy charges in specific courses.

Re-induction chemoimmunotherapy with epratuzumab in relapsed acute lymphoblastic leukemia (ALL): Phase II results from Children's Oncology Group (COG) study ADVL04P2

BACKGROUND

Given the success of immunotherapeutic approaches in hematologic malignancies, the COG designed a phase I/II study to determine whether the addition of epratuzumab (anti-CD22) to an established chemotherapy platform improves rates of second remission (CR2) in pediatric patients with B-lymphoblastic leukemia (B-ALL) and early bone marrow relapse.

PROCEDURE

Therapy consisted of three established blocks of re-induction chemotherapy. Epratuzumab (360 mg/m(2)/dose) was combined with chemotherapy on weekly × 4 (B1) and twice weekly × 4 [eight doses] (B2) schedules during the first re-induction block. Remission rates and minimal residual disease (MRD) status were compared to historical rates observed with the identical chemotherapy platform alone.

RESULTS

CR2 was achieved in 65 and 66%, of the evaluable B1 (n = 54) and B2 patients (n = 60), respectively; unchanged from that observed historically without epratuzumab. Rates of MRD negativity (<0.01%) were 31% in B1 (P = 0.4128) and 39% in B2 patients (P = 0.1731), compared to 25% in historical controls. The addition of epratuzumab was well tolerated, with a similar toxicity profile to that observed with the re-induction chemotherapy platform regimen alone.

CONCLUSIONS

Epratuzumab was well tolerated in combination with re-induction chemotherapy. While CR2 rates were not improved compared to historical controls treated with chemotherapy alone, there was a non-significant trend towards improvement in MRD response with the addition of epratuzumab (twice weekly for eight doses) to re-induction chemotherapy.

The impact of chemotherapy shortages on COG and local clinical trials: a report from the Children's Oncology Group

BACKGROUND

Oncology drug shortage is associated with increased patient adverse events and decreased enrollment on clinical trials for adult patients; however, the impact of oncology drug shortages has not been well studied in children with cancer.

PROCEDURE

The Children's Oncology Group (COG) distributed a 5-item survey to 226 COG site-specific principal investigators (PI's) and 14-item survey to 161 COG pharmacists to gather data the impact of chemotherapeutic shortages on clinical trials and patient care.

RESULTS

The response rate was 66.4% (150/226) for PI's and 29.8% (48/161) for pharmacists. COG PI's reported daunorubicin (73%), methotrexate (56%), asparaginase/PEG-asparaginase (42%), doxorubicin (26%), thiotepa (21%), and cytarabine (20%) were most commonly in shortage, while COG pharmacists reported daunorubicin (80%), methotrexate (66%), vincristine (21%), thiotepa (41%), asparaginase/PEG-asparaginase (34%), and cytarabine (34%) were most commonly in shortage over the past two years. Pharmacists were twice as likely to report a shortage compared with PI's (OR 2.1, 95% CI: 1.6-2.7, P < 0.0001). Fifty percent (74/147) of COG PI's reported at least one patient enrolled on a clinical trial was impacted by drug shortage, and 66% (98/148) of COG PI's reported at least one patient had clinical care impacted by drug shortage.

CONCLUSIONS

Chemotherapy shortages remain widespread across institutions, hinder clinical trials, and may contribute to adverse events in children with cancer. The increased frequency of chemotherapy shortages reported by pharmacists suggests that pharmacist efforts may mitigate negative impact chemotherapy shortages. Over half of pediatric institutions are implementing recommendations to address shortages, such as cross-institutional collaboration and center-level guidelines.

Improving the outcome for children with cancer: Development of targeted new agents

The outcome for children with cancer has improved significantly over the past 60 years, with greater than 80% of patients today becoming 5-year survivors. Despite this progress, cancer remains the leading cause of death from disease in children in the United States, and significant short-term and long-term treatment toxicities continue to impact the majority of children with cancer. The development of targeted new agents offers the prospect of potentially more effective and less toxic treatment for children. More than a decade since imatinib mesylate was introduced into the treatment of children with Philadelphia chromosome-positive acute lymphoblastic leukemia, transforming its outcome, a range of targeted agents has undergone study in pediatric cancer patients. Early lessons learned from these studies include a better understanding of the adverse event profile of these drugs in children, the challenge of developing pediatric-specific formulations, and the continued reliance on successful development for adult cancer indications on pediatric drug development. The collaborative research infrastructure for children with cancer in the United States is well positioned to advance novel treatments into clinical investigations for a spectrum of rare and ultra-rare childhood cancers. A greater investment of resources in target discovery and validation can help drive much needed development of new, more effective treatments for children with cancer.

Growth plate abnormalities in pediatric cancer patients undergoing phase 1 anti-angiogenic therapy: a report from the Children's Oncology Group Phase I Consortium

BACKGROUND

Pre-clinical studies suggest that anti-angiogenic agents may be toxic to the developing growth plate. The purpose of this study was to evaluate the incidence of growth plate abnormalities in children with refractory cancer undergoing anti-angiogenic therapy.

PROCEDURE

Targeted radiographic studies from 53 subjects enrolled on six separate Children's Oncology Group Phase 1 and Pilot Consortium clinical trials evaluating new anti-cancer agents interfering with angiogenesis were reviewed. Subjects received tyrosine kinase inhibitors with anti-angiogenic effects (n = 35), monoclonal antibodies targeting vascular endothelial growth factor (VEGF) (n = 13), or angiopoietin (n = 5). Radiographs of their distal femur/proximal tibia were obtained at baseline. Follow-up radiographs were obtained after odd-numbered treatment cycles in patients with open growth plates who did not experience disease progression prior to cycle 3.

RESULTS

Baseline and follow-up growth plate radiographs were acquired in 48/53 (90%) of patients. Five patients (9.4%), all of whom received a specific VEGF/VEGFR blocking agent (sunitinib [n = 1] or pazopanib [n = 4]), had growth plate abnormalities. Four patients had growth plate widening that was apparent on at least two successive radiographs, but was not confirmed by MRI. The fifth patient had progressive growth plate widening and evidence of physeal cartilage hypertrophy on MRI. Subsequent off treatment radiographs showed that the growth plate changes were reversible.

CONCLUSION

Growth plate abnormalities occur in a small, but relevant number of patients undergoing anti-angiogenic therapy. These results support the need for growth plate monitoring in children with open growth plates who are receiving anti-angiogenic therapy, and for improved methods to assess toxicity of anti-angiogenic agents to the developing skeleton.

Drug discovery in paediatric oncology: roadblocks to progress

Approval of new cancer drugs for paediatric patients generally occurs after their development and approval for treating adult cancers. As most drug development occurs in the industry setting, the relatively small market of paediatric oncology does not provide the financial incentives for companies to actively pursue paediatric oncology solutions. Indeed, between 1948 and January 2003 the FDA approved 120 new cancer drugs, of which only 30 have been used in children. This slow rate of development must be addressed in a meaningful way if we are to make progress in the most pressing settings in childhood cancer. In this Viewpoint article, the key opinion leaders in the field weigh in and offer practical advice on how to address this issue.

Pharmacokinetic and pharmacodynamic properties of calaspargase pegol Escherichia coli L-asparaginase in the treatment of patients with acute lymphoblastic leukemia: results from Children's Oncology Group Study AALL07P4

PURPOSE

Asparaginase is a critical agent used to treat acute lymphoblastic leukemia (ALL). Pegaspargase (SS-PEG), a pegylated form of Escherichia coli L-asparaginase with a succinimidyl succinate (SS) linker, is the first-line asparaginase product used in Children's Oncology Group (COG) ALL trials. Calaspargase pegol (SC-PEG) replaces the SS linker in SS-PEG with a succinimidyl carbamate linker, creating a more stable molecule. COG AALL07P4 was designed to determine the pharmacokinetic and pharmacodynamic comparability of SC-PEG to SS-PEG in patients with newly diagnosed high-risk (HR) B-cell ALL.

PATIENTS AND METHODS

A total of 165 evaluable patients were randomly assigned at a 2:1 ratio to receive SC-PEG at 2,100 (SC-PEG2100; n = 69) or 2,500 IU/m(2) (SC-PEG2500; n = 42) versus SS-PEG 2,500 IU/m(2) (SS-PEG2500; n = 54) as part of an otherwise identical chemotherapy regimen. The groups were similar demographically, except more female patients received SC-PEG2500.

RESULTS

The mean half-life of plasma asparaginase activity for both SC-PEG doses was approximately 2.5× longer than that of SS-PEG2500. The total systemic exposure, as defined by induction area under the curve from time 0 to 25 days, was greater with SC-PEG2500 than with SS-PEG2500 or SC-PEG2100. The proportion of patients with plasma asparaginase activity ≥ 100 mIU/mL and ≥ 400 mIU/mL was higher in patients who received SC-PEG as compared with SS-PEG2500. After one dose of pegylated asparaginase on induction day 4, plasma asparagine was undetectable for 11 days for SS-PEG2500 and 18 days for both SC-PEG groups.

CONCLUSION

SC-PEG2500 achieves a significantly longer period of asparaginase activity above defined thresholds and asparagine depletion compared with SS-PEG2500 and has a comparable toxicity profile in children with HR B-cell ALL.

A liquid chromatography/tandem mass spectrometry method for determination of obatoclax in human plasma

We describe a selective and highly sensitive high-performance liquid chromatography-electrospray ionization-collision induced dissociation-tandem mass spectrometry (HPLC-ESI-CID-MS/MS) assay for the pan-antiapoptotic Bcl-2 family inhibitor, obatoclax, in human plasma. Fifty μL plasma specimens were prepared by addition of extraction solution consisting of Mobile Phase A (10mM ammonium formate (aq) titrated to pH of 3.0 with formic acid): Mobile Phase B (100% methanol) (20:80, v,v) and internal standard followed by centrifugation. HPLC separations were performed on a Waters, YMC-Pack™, ODS-AQ™ S-3 analytical column with LC mobile phase A and B. Linearity and sensitivity was assessed over a linear range of 0.04-25ng/ml at eleven concentrations. The lower limit of quantification for obatoclax was 0.04ng/mL. The intra-day precision based on the standard deviation of replicates of quality control (QC) samples ranged from 0.9 to 5.1% and the accuracy ranged from 98.9 to 106.8%. Stability studies performed replicate sets of QC samples (0.1ng/mL, 2.5ng/mL, and 15ng/mL) showed that obatoclax in human plasma was stable at room temperature for 24h as well as at -80°C for 1m and 2y. Stability was also demonstrated after 3 freeze/thaw cycles (RT to -80°C). The analytical method showed excellent sensitivity, precision, and accuracy. This method is robust and has been successfully employed in a Children's Oncology Group Phase 1 Consortium study of obatoclax in children with cancer.