Phase II study of vemurafenib in children and young adults with tumors harboring BRAF V600 mutations: NCI-COG pediatric MATCH trial (APEC1621) Arm G.

BACKGROUND: This is a phase II subprotocol of the NCI-COG Pediatric MATCH study evaluating vemurafenib, a selective oral inhibitor of BRAF V600 mutated kinase, in patients with relapsed or refractory solid tumors harboring BRAF V600 mutations. METHODS: Patients received vemurafenib at 550 mg/m2 (maximum 960 mg/dose) orally twice daily for 28-day cycles until progression or intolerable toxicity. The primary aim was to determine the objective response rate and secondary objectives included estimating progression-free survival and assessing the tolerability of vemurafenib. RESULTS: Twenty-two patients matched to the subprotocol and 4 patients (18%) enrolled. Primary reasons for non-enrollment were ineligibility due to exclusions of low-grade glioma (nâ=â7) and prior BRAF inhibitor therapy (nâ=â7). Enrolled diagnoses were one each of histiocytosis, ameloblastoma, Ewing sarcoma, and high-grade glioma, all with BRAF V600E mutations. Treatment was overall tolerable with mostly expected grade 1/2 adverse events (AE). Grade 3 or 4 AE on treatment were acute kidney injury, hyperglycemia, and maculopapular rash. One patient came off therapy due to AE. One patient (glioma) had an objective partial response and remained on protocol therapy for 15 cycles. CONCLUSION: There was a low accrual rate on this MATCH subprotocol, with only 18% of those who matched with BRAFV600 mutations enrolling, resulting in early termination, and limiting study results (ClinicalTrials.gov Identifier: NCT03220035).

Phase II Study of Ulixertinib in Children and Young Adults With Tumors Harboring Activating Mitogen-Activated Protein Kinase Pathway Alterations: APEC1621J of the National Cancer Institute-Children's Oncology Group Pediatric MATCH Trial.

PURPOSE: The National Cancer Institute-Children's Oncology Group (NCI-COG) Pediatric MATCH trial assigns patients age 1-21 years with refractory malignancies to phase II treatment arms of molecularly targeted therapies on the basis of genetic alterations detected in their tumor. Patients with activating alterations in the mitogen-activated protein kinase pathway were treated with ulixertinib, an extracellular signal-regulated kinase (ERK)1/2 inhibitor. METHODS: As there were no previous pediatric data, ulixertinib was initially tested in a dose escalation cohort to establish the recommended phase II dose (RP2D) before proceeding to the phase II cohort. Ulixertinib was administered at 260 mg/m2/dose orally twice a day (dose level 1 [DL1], n = 15) or 350 mg/m2/dose orally twice a day (DL2, n = 5). The primary end point was objective response rate; secondary end points included safety/tolerability and progression-free survival (PFS). RESULTS: Twenty patients (median 12 years; range, 5-20) were treated, all evaluable for response. CNS tumors comprised 55% (11/20) of diagnoses, with high-grade glioma and low-grade glioma most common (n = 5 each). All CNS tumors except one harbored BRAF fusions or V600E mutations. Rhabdomyosarcoma (n = 5) was the most frequent non-CNS diagnosis. DL1 was declared the RP2D in the dose escalation cohort after dose-limiting toxicities in Cycle 1 occurred in 1/6 patients at DL1 and 2/5 patients at DL2, including fatigue, anorexia, rash, nausea, vomiting, diarrhea, dehydration, hypoalbuminemia, and hypernatremia. No objective responses were observed. Six-month PFS was 37% (95% CI, 17 to 58). Three patients with BRAF-altered CNS tumors achieved stable disease >6 months. CONCLUSION: Ulixertinib, a novel targeted agent with no previous pediatric data, was successfully evaluated in a national precision medicine basket trial. The pediatric RP2D of ulixertinib is 260 mg/m2/dose orally twice a day. Limited single-agent efficacy was observed in a biomarker-selected cohort of refractory pediatric tumors.

Olaparib for childhood tumors harboring defects in DNA damage repair genes: arm H of the NCI-COG Pediatric MATCH trial.

BACKGROUND: The National Cancer Institute-Children's Oncology Group Pediatric Molecular Analysis for Therapy Choice (MATCH) precision oncology platform trial enrolled children aged 1-21 years with treatment-refractory solid tumors and predefined actionable genetic alterations. Patients with tumors harboring alterations in DNA damage repair (DDR) genes were assigned to receive olaparib. METHODS: Tumor and blood samples were submitted for centralized molecular testing. Tumor and germline sequencing were conducted in parallel. Olaparib was given twice daily for 28-day cycles starting at a dose 30% lower than the adult recommended phase 2 dose (RP2D). The primary endpoint was the objective response. RESULTS: Eighteen patients matched (1.5% of those screened) based on the presence of a deleterious gene alteration in BRCA1/2, RAD51C/D, or ATM detected by tumor sequencing without germline subtraction or analysis of loss of heterozygosity (LOH). Eleven (61%) harbored a germline mutation, with only one exhibiting LOH. Six patients enrolled and received the olaparib starting dose of 135 mg/m2/dose. Two participants were fully evaluable; 4 were inevaluable because <85% of the prescribed dose was administered during cycle 1. There were no dose-limiting toxicities or responses. Minimal hematologic toxicity was observed. CONCLUSION: Most DDR gene alterations detected in Pediatric MATCH were germline, monoallelic, and unlikely to confer homologous recombination deficiency predicting sensitivity to olaparib monotherapy. The study closed due to poor accrual. CLINICALTRIALS.GOV IDENTIFIER: NCT03233204. IRB approved: initial July 24, 2017.

A phase 1 trial utilizing a pharmacokinetic endpoint to determine the optimal dose of ramucirumab in children and adolescents with relapsed or refractory solid tumors, including central nervous system tumors.

BACKGROUND: Ramucirumab is a monoclonal antibody that binds the extracellular domain of vascular endothelial growth factor receptor (VEGFR-2) and prevents binding of VEGF ligands. Based on population pharmacokinetic (PK) analysis and correlation with efficacy in adults, a target steady state trough concentration (Css,min ) ≥ 50 µg/mL was established. PROCEDURES: This phase 1 trial (ADVL1416) used a rolling six design and a PK primary endpoint to define the recommended phase 2 dose (RP2D) of ramucirumab in children with recurrent/refractory solid tumors. Two dose levels (DL) were planned (DL1: 8 mg/kg, DL2: 12 mg/kg administered intravenously [IV] every 2 weeks). Toxicity during the initial 6 weeks was used to assess maximum tolerated dose (MTD). Cycle 1 Day 42 trough (Cmin ) ≥ 50 µg/mL was the target concentration for the PK endpoint. At the RP2D, cohorts for PK expansion and children with central nervous tumors were planned. RESULTS: Twenty-nine patients were enrolled; 28 were eligible; median age [range] = 13.5 [1-21] years; 22 were evaluable for the PK endpoint. Dose-limiting proteinuria occurred at both DLs; however, the MTD was not exceeded. At DL2 (12 mg/kg), the median Day 42 Cmin (n = 16) was 87.8 µg/mL; 15 of 16 patients achieved a Cmin  ≥ 50 µg/mL. CONCLUSION: Ramucirumab was well tolerated in children and adolescents with solid tumors. The RP2D for ramucirumab was 12 mg/kg IV every 2 weeks. This trial demonstrates the feasibility of incorporating a primary PK endpoint to determine dose escalation and the RP2D in children. Studies of ramucirumab in children with selected solid tumors are ongoing.

Tazemetostat for tumors harboring SMARCB1/SMARCA4 or EZH2 alterations: results from NCI-COG pediatric MATCH APEC1621C.

BACKGROUND: National Cancer Institute-Children's Oncology Group Pediatric Molecular Analysis for Therapy Choice assigns patients aged 1-21 years with refractory solid tumors, brain tumors, lymphomas, and histiocytic disorders to phase II trials of molecularly targeted therapies based on detection of predefined genetic alterations. Patients whose tumors harbored EZH2 mutations or loss of SMARCB1 or SMARCA4 by immunohistochemistry were treated with EZH2 inhibitor tazemetostat. METHODS: Patients received tazemetostat for 28-day cycles until disease progression or intolerable toxicity (max 26 cycles). The primary endpoint was objective response rate; secondary endpoints included progression-free survival and tolerability of tazemetostat. RESULTS: Twenty patients (median age = 5 years) enrolled, all evaluable for response and toxicities. The most frequent diagnoses were atypical teratoid rhabdoid tumor (n = 8) and malignant rhabdoid tumor (n = 4). Actionable alterations consisted of SMARCB1 loss (n = 16), EZH2 mutation (n = 3), and SMARCA4 loss (n = 1). One objective response was observed in a patient with non-Langerhans cell histiocytosis with SMARCA4 loss (26 cycles, 1200 mg/m2/dose twice daily). Four patients with SMARCB1 loss had a best response of stable disease: epithelioid sarcoma (n = 2), atypical teratoid rhabdoid tumor (n = 1), and renal medullary carcinoma (n = 1). Six-month progression-free survival was 35% (95% confidence interval [CI] = 15.7% to 55.2%) and 6-month overall survival was 45% (95% CI = 23.1% to 64.7%). Treatment-related adverse events were consistent with prior tazemetostat reports. CONCLUSIONS: Although tazemetostat did not meet its primary efficacy endpoint in this population of refractory pediatric tumors (objective response rate = 5%, 90% CI = 1% to 20%), 25% of patients with multiple histologic diagnoses experienced prolonged stable disease of 6 months and over (range = 9-26 cycles), suggesting a potential effect of tazemetostat on disease stabilization.

A Phase I/II Trial of Nivolumab plus Ipilimumab in Children and Young Adults with Relapsed/Refractory Solid Tumors: A Children's Oncology Group Study ADVL1412.

PURPOSE: In many cancers, nivolumab in combination with ipilimumab improves response rates compared with either agent alone, but the combination has not been evaluated in childhood cancer. We conducted a phase I/II trial of nivolumab plus ipilimumab in children and young adults with recurrent/refractory solid tumors. PATIENTS AND METHODS: ADVL1412, Part C assessed safety of nivolumab plus ipilimumab at two dose levels (DL): DL1 1 mg/kg of each drug and DL2 3 mg/kg nivolumab plus 1 mg/kg ipilimumab. Part D evaluated response at the recommended phase II dose (RP2D) in Ewing sarcoma, rhabdomyosarcoma, and osteosarcoma. Part E tested DL3 (1 mg/kg nivolumab plus 3 mg/kg ipilimumab) in Ewing sarcoma and rhabdomyosarcoma. Tumor response was measured using RECIST v1.1. Pharmacokinetics and PD-L1 expression on archival tissues were assessed. RESULTS: Fifty-five eligible patients enrolled. Based on safety, tolerability, and similar drug exposure to the same doses administered in adults, DL2 was defined as the pediatric RP2D. Among 41 patients treated at the RP2D, 2 patients experienced dose-limiting toxicities during cycle 1, and 4 patients experienced toxicities beyond that period. Two patients had clinically significant sustained partial responses (1 rhabdomyosarcoma, 1 Ewing sarcoma) and 4 had stable disease. Among 8 patients treated at DL3, 3 dose-limiting toxicities (DLT) occurred, all immune-related adverse events; no objective responses were observed. CONCLUSIONS: The RP2D of nivolumab (3 mg/kg) plus ipilimumab (1 mg/kg) is well tolerated in children and young adults with solid tumors and shows some clinical activity. Increased dose of ipilimumab (3 mg/kg) plus nivolumab (1 mg/kg) was associated with increased toxicity without clinical benefit.

Phase II Study of Selumetinib in Children and Young Adults With Tumors Harboring Activating Mitogen-Activated Protein Kinase Pathway Genetic Alterations: Arm E of the NCI-COG Pediatric MATCH Trial.

PURPOSE: The NCI-COG Pediatric MATCH trial assigns patients age 1-21 years with relapsed or refractory solid tumors, lymphomas, and histiocytic disorders to phase II studies of molecularly targeted therapies on the basis of detection of predefined genetic alterations. Patients with tumors harboring mutations or fusions driving activation of the mitogen-activated protein kinase (MAPK) pathway were treated with the MEK inhibitor selumetinib. METHODS: Patients received selumetinib twice daily for 28-day cycles until disease progression or intolerable toxicity. The primary end point was objective response rate; secondary end points included progression-free survival and tolerability of selumetinib. RESULTS: Twenty patients (median age: 14 years) were treated. All were evaluable for response and toxicities. The most frequent diagnoses were high-grade glioma (HGG; n = 7) and rhabdomyosarcoma (n = 7). Twenty-one actionable mutations were detected: hotspot mutations in KRAS (n = 8), NRAS (n = 3), and HRAS (n = 1), inactivating mutations in NF1 (n = 7), and BRAF V600E (n = 2). No objective responses were observed. Three patients had a best response of stable disease including two patients with HGG (NF1 mutation, six cycles; KRAS mutation, 12 cycles). Six-month progression-free survival was 15% (95% CI, 4 to 34). Five patients (25%) experienced a grade 3 or higher adverse event that was possibly or probably attributable to study drug. CONCLUSION: A national histology-agnostic molecular screening strategy was effective at identifying children and young adults eligible for treatment with selumetinib in the first Pediatric MATCH treatment arm to be completed. MEK inhibitors have demonstrated promising responses in some pediatric tumors (eg, low-grade glioma and plexiform neurofibroma). However, selumetinib in this cohort with treatment-refractory tumors harboring MAPK alterations demonstrated limited efficacy, indicating that pathway mutation status alone is insufficient to predict response to selumetinib monotherapy for pediatric cancers.

Actionable Tumor Alterations and Treatment Protocol Enrollment of Pediatric and Young Adult Patients With Refractory Cancers in the National Cancer Institute-Children's Oncology Group Pediatric MATCH Trial.

PURPOSE: The National Cancer Institute-Children's Oncology Group Pediatric MATCH trial aimed to facilitate evaluation of molecular-targeted therapies in biomarker-selected cohorts of childhood and young adult patients with cancer by screening tumors for actionable alterations. PATIENTS AND METHODS: Tumors from patients age 1-21 years with refractory solid tumors, lymphomas, or histiocytic disorders were subjected to cancer gene panel sequencing and limited immunohistochemistry to identify actionable alterations for assignment to phase II treatment arms. The rates of treatment arm assignment and enrollment were compared between clinical and demographic groups. RESULTS: Testing was completed for 94.7% of tumors submitted. Actionable alterations were detected in 31.5% of the first 1,000 tumors screened, with treatment arm assignment and enrollment occurring in 28.4% and 13.1% of patients, respectively. Assignment rates varied by tumor histology and were higher for patients with CNS tumors or enrolled at Pediatric Early Phase Clinical Trials Network sites. A reported history of prior clinical molecular testing was associated with higher assignment and enrollment rates. Actionable alterations in the mitogen-activated protein kinase signaling pathway were most frequent (11.2%). The most common reasons provided for not enrolling on treatment arms were patients receiving other treatment or poor clinical status. CONCLUSION: The Pediatric MATCH trial has proven the feasibility of a nationwide screening Protocol for identification of actionable genetic alterations and assignment of pediatric and young adult patients with refractory cancers to trials of molecularly targeted therapies. These data support the early use of tumor molecular screening for childhood patients with cancer whose tumors have not responded to standard treatments.

Toxicity and pharmacokinetics of actinomycin-D and vincristine in children and adolescents: Children's Oncology Group Study ADVL06B1.

Actinomycin-D and vincristine are cytotoxic drugs commonly used to treat cancers in children. This prospective study assessed pharmacokinetic variability and toxicity of these drugs in children. Blood samples were collected in 158 patients. Actinomycin-D or vincristine concentrations were quantified using high-performance liquid chromatography-tandem mass spectrometry. Pharmacokinetic parameters were estimated using non-compartmental methods. Target toxicities were collected prospectively. Actinomycin-D pharmacokinetics (n = 52 patients) were highly variable. The median (coefficient of variation, CV%) area under the concentration-time curve (AUC) was 332 ng/mL·h. (110%); clearance was 4.6 L/h/m2 (90%); half-life was 25 h (60%). No patient met the defined criteria for myelosuppression. In multivariate analysis, none of the demographic nor pharmacokinetic parameters was predictors of acute hepatotoxicity. Vincristine pharmacokinetics (n = 132 patients) demonstrated substantial variability. The median (CV%) AUC was 78 ng/mL·h (98%); clearance was 17.2 L/h/m2 (67%); half-life was 14.6 h (73%). In multivariate analysis, the effect of increasing age for a given BSA was an increase in neuropathy while the effect of increasing BSA for a given age was a decrease in neuropathy. Conclusion: Pharmacokinetics of both drugs were highly variable. For actinomycin-D, there was no correlation between demographic or pharmacokinetic parameters and target toxicities. For vincristine, the correlations of age and BSA and neuropathy are confounded by the correlation between age and BSA in children and the ability to ascertain neuropathy in infants. Variability may be attributed to dose reductions and capped doses for both drugs. Investigation of BSA-based dosing in young children is warranted to decrease variability of exposure.

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.

ADVL1522: A phase 2 study of lorvotuzumab mertansine (IMGN901) in children with relapsed or refractory wilms tumor, rhabdomyosarcoma, neuroblastoma, pleuropulmonary blastoma, malignant peripheral nerve sheath tumor, or synovial sarcoma-A Children's Oncology Group study.

BACKGROUND: Lorvotuzumab mertansine (IMGN901) is an antibody-drug conjugate linking an antimitotic agent (DM1) to an anti-CD56 antibody (lorvotuzumab). Preclinical efficacy has been noted in Wilms tumor, rhabdomyosarcoma, and neuroblastoma. Synovial sarcoma, malignant peripheral nerve sheath tumor (MPNST), and pleuropulmonary blastoma also express CD56. A phase 2 trial of lorvotuzumab mertansine was conducted to assess its efficacy, recommended phase 2 dose, and toxicities. METHODS: Eligible patients had relapsed after or progressed on standard therapy for their tumor type. Lorvotuzumab mertansine (110 mg/m2 per dose) was administered at the adult recommended phase 2 dose intravenously on days 1 and 8 of 21-day cycles. Dexamethasone premedication was used. Pharmacokinetic samples, peripheral blood CD56-positive cell counts, and tumor CD56 expression were assessed. RESULTS: Sixty-two patients enrolled. The median age was 14.3 years (range, 2.8-29.9 years); 35 were male. Diagnoses included Wilms tumor (n = 17), rhabdomyosarcoma (n = 17), neuroblastoma (n = 12), synovial sarcoma (n = 10), MPNST (n = 5), and pleuropulmonary blastoma (n = 1). Five patients experienced 9 dose-limiting toxicities: hyperglycemia (n = 1), colonic fistula (n = 1) with perforation (n = 1), nausea (n = 1) with vomiting (n = 1), increased alanine aminotransferase in cycle 1 (n = 2), and increased alanine aminotransferase in cycle 2 (n = 1) with increased aspartate aminotransferase (n = 1). Non-dose-limiting toxicities (grade 3 or higher) attributed to lorvotuzumab mertansine were rare. The median values of the maximum concentration, half-life, and area under the curve from zero to infinity for DM1 were 0.87 µg/mL, 35 hours, and 27.9 µg/mL h, respectively. Peripheral blood CD56+ leukocytes decreased by 71.9% on day 8. One patient with rhabdomyosarcoma had a partial response, and 1 patient with synovial sarcoma achieved a delayed complete response. CONCLUSIONS: Lorvotuzumab mertansine (110 mg/m2 ) is tolerated in children at the adult recommended phase 2 dose; clinical activity is limited.

Do intravenous fluid substitutions influence methotrexate clearance? An unanticipated impact of an intravenous sodium bicarbonate drug shortage.

BACKGROUND: National drug shortages of essential medications for childhood cancer have increasingly posed a challenge in the treatment of patients. The efficacy of standardized supportive care practices to avoid treatment-related toxicities may be limited during these drug shortages. High-dose methotrexate (HDMTX) plays a critical role in modern treatment protocols for acute lymphoblastic leukemia and requires stringent supportive care measures to mitigate toxicity. As the result of a national intravenous (IV) sodium bicarbonate shortage, institutional standard HDMTX supportive care guidelines had to be modified. We describe the unanticipated consequences on HDMTX clearance. METHODS: We performed a retrospective chart review assessing the impact of alternative compositions of IV fluids on the mean 24-h methotrexate levels (Cpss ) of 25 patients receiving 76 total HDMTX infusions at Texas Children's Hospital Cancer Center from March to October 2017. During the sodium bicarbonate drug shortage, all patients received IV hydration consisting of either dextrose 5%, 0.45% normal saline (D5 ½ NS-Group A) or dextrose 5%, 0.2% normal saline (D5 » NS-Group B). RESULTS: Patients receiving a higher total sodium dose demonstrated significantly lower Cpss (25.36 ± 16.6 µMol) compared to patients receiving less sodium (53.9 ± 37.9 µMol; P < .001). CONCLUSIONS: Our report shows that in the setting of IV sodium bicarbonate shortage, the composition of hydration IV fluids may affect methotrexate clearance. Patient who received a higher sodium load had a lower 24-h methotrexate level. This demonstrates the potential for unanticipated outcomes resulting from national drug shortages.

Nivolumab in children and young adults with relapsed or refractory solid tumours or lymphoma (ADVL1412): a multicentre, open-label, single-arm, phase 1-2 trial.

BACKGROUND: Immune checkpoint inhibitors targeting PD-1 have shown clinical benefit in adults with cancer, but data on these drugs in children are scarce. We did a phase 1-2 study of nivolumab, a PD-1 blocking monoclonal antibody, to determine its safety, pharmacokinetics, and antitumour activity in children and young adults with recurrent or refractory non-CNS solid tumours or lymphoma. METHODS: We did a multicentre, open-label, single-arm, dose-confirmation and dose-expansion, phase 1-2 trial in 23 hospitals in the USA. Eligible patients for part A (dose-confirmation phase) of the study were aged 1-18 years with solid tumours with measurable or evaluable disease (by Response Evaluation Criteria in Solid Tumors [RECIST] version 1.1) regardless of histology. Eligible patients for part B (dose-expansion phase) were aged 1-30 years with measurable disease (by RECIST criteria) in the following disease cohorts: rhabdomyosarcoma, Ewing sarcoma, osteosarcoma, neuroblastoma, Hodgkin lymphoma, non-Hodgkin lymphoma, and melanoma. Patients in part A and were given nivolumab 3 mg/kg intravenously over 60 min on days 1 and 15 of a 28-day cycle in a rolling 6 study design with de-escalation upon dose-limiting toxicities to establish the recommended phase 2 dose. Patients in part B were given the recommended phase 2 dose. The primary outcomes were the tolerability, systemic exposure, maximum tolerated dose, and the antitumour activity of nivolumab at the adult recommended dose in children and young adults. This trial is registered with ClinicalTrials.gov, NCT02304458, with follow-up ongoing and is closed to new participants. FINDINGS: 85 patients were enrolled between Feb 22, 2015, and Dec 31, 2018, and 75 patients were fully evaluable for toxicity. Median follow-up was 30 days (IQR 27-83). In part A, 13 patients were enrolled and 12 were evaluable for toxicity. There were no dose de-escalations or dose-limiting toxicities and nivolumab 3 mg/kg was confirmed as the paediatric recommended phase 2. 72 patients were enrolled in part B and 63 were evaluable for toxicity. Five (7%) patients in part B had dose-limiting toxicities. The most common overall toxicity was anaemia (35 [47%] of 75 patients; five patients had grade 3 or grade 4) and non-haematological toxicity was fatigue (28 [37%] patients; none had grade 3 or grade 4). Responses were observed in patients with lymphoma (three [30%] of ten with Hodgkin lymphoma and one [10%] of ten with non-Hodgkin lymphoma; all responders had PD-L1 expression). Objective responses were not observed in other tumour types. INTERPRETATION: Nivolumab was safe and well tolerated in children and young adults and showed clinical activity in lymphoma. Nivolumab showed no significant single-agent activity in the common paediatric solid tumours. This study defines the recommended phase 2 dose and establishes a favourable safety profile for nivolumab in children and young adults, which can serve as the basis for its potential study in combinatorial regimens for childhood cancer. FUNDING: Bristol-Myers Squibb, Children's Oncology Group, National Institutes of Health, Cookies for Kids Cancer Foundation.

Phase I Clinical Trial of the Wee1 Inhibitor Adavosertib (AZD1775) with Irinotecan in Children with Relapsed Solid Tumors: A COG Phase I Consortium Report (ADVL1312).

PURPOSE: Adavosertib (AZD1775), an inhibitor of WEE1 kinase, potentiates replicative stress induced by oncogenes or chemotherapy. Antitumor activity of adavosertib has been demonstrated in preclinical models of pediatric cancer. This phase I trial was performed to define dose-limiting toxicities (DLT), recommended phase II dose (RP2D), and pharmacokinetics of adavosertib in combination with irinotecan in children and adolescents with relapsed or refractory solid tumors or primary central nervous system tumors. PATIENTS AND METHODS: Using a 3+3 escalation design, five dose cohorts of the combination of adavosertib and irinotecan (50/70; 65/70; 65/90; 85/90; 110/90 mg/m2/day) delivered on days 1-5 of a 21-day cycle were studied. Pharmacokinetics and analysis of peripheral blood γH2AX was performed. RESULTS: Thirty-seven patients were enrolled; 27 were evaluable. The median (range) age was 14 (2-20) years. Twenty-five (93%) received prior chemotherapy (median, three regimens) and 21 (78%) received prior radiotherapy. Eleven patients had a primary central nervous system (CNS) malignancy. Common toxicities were hematologic and gastrointestinal. Two patients receiving adavosertib (110 mg/m2) in combination with irinotecan (90 mg/m2) experienced dose-limiting grade 3 dehydration. A patient with Ewing sarcoma had a confirmed partial response and 2 patients (ependymoma and neuroblastoma) had prolonged stable disease (≥ 6 cycles). Pharmacokinetics of adavosertib were variable but generally dose proportional and clearance was lower in younger patients. CONCLUSIONS: Adavosertib (85 mg/m2) in combination with irinotecan (90 mg/m2) administered orally for 5 days was the MTD in children and adolescents with solid and CNS tumors.

Phase 1/2 trial of talazoparib in combination with temozolomide in children and adolescents with refractory/recurrent solid tumors including Ewing sarcoma: A Children's Oncology Group Phase 1 Consortium study (ADVL1411).

PURPOSE: We conducted a phase 1/2 trial of the poly(ADP-ribose) polymerase 1/2 inhibitor talazoparib in combination with low-dose temozolomide (TMZ) to determine the dose-limiting toxicities (DLTs), recommended phase 2 dose (RP2D), and pharmacokinetics of this combination in children with recurrent/refractory solid tumors; and to explore clinical activity in Ewing sarcoma (EWS) (NCT02116777). METHODS: Talazoparib (400-600 µg/m2 /dose, maximum daily dose 800-1000 µg) was administered q.d. or b.i.d. orally on day 1 followed by q.d. dosing concomitant with q.d. dosing of oral TMZ (20-55 mg/m2 /day) on days 2 to 6, every 28 days. RESULTS: Forty patients, aged 4 to 25 years, were enrolled. Talazoparib was increased to 600 µg/m2 /dose b.i.d. on day 1, and q.d. thereafter, with 20 mg/m2 /day of TMZ, without DLTs. TMZ was subsequently increased, during which dose-limiting neutropenia and thrombocytopenia occurred in two of three subjects at 55 mg/m2 /day, two of six subjects at 40 mg/m2 /day, and one of six subjects at 30 mg/m2 /day. During dose-finding, two of five EWS and four of 25 non-EWS subjects experienced prolonged stable disease (SD), and one subject with malignant glioma experienced a partial response. In phase 2, 0 of 10 EWS subjects experienced an objective response; two experienced prolonged SD. CONCLUSIONS: Talazoparib and low-dose TMZ are tolerated in children with recurrent/refractory solid tumors. Reversible neutropenia and thrombocytopenia were dose limiting. The RP2D is talazoparib 600 µg/m2 b.i.d. on day 1 followed by 600 µg/m2 q.d. on days 2 to 6 (daily maximum 1000 µg) in combination with temozolomide 30 mg/m2 /day on days 2 to 6. Antitumor activity was not observed in EWS, and limited antitumor activity was observed in central nervous system tumors.

Participant Engagement in Translational Genomics Research: Respect for Persons-and Then Some.

The expansion of both formal and informal frameworks of "engaged" research in translational research settings raises emerging and substantial normative concerns. In this article, we draw on findings from a focus group study with members of a national consortium of translational genomic research sites. The goals were to catalog informal participant engagement practices, to explore the perceived roots of these practices and the motivations of research staff members for adopting them, and to reflect on their ethical implications. We learned that participant engagement is a deliberate strategy by research staff members both to achieve instrumental research goals and to "do research differently" in response to past research injustices. While many of the participant engagement practices used in translational genomic research are not new, important insights can be gained through a closer examination of the specific contours of participant engagement in this context. These practices appear to have been shaped by the professional training of genetic counselors and by the interests and needs of participants who enroll in clinical genomics studies. The contours of this contemporary application of engaged research principles have relevance not only to clinical genomics research but also to translational research broadly, particularly for how communities of clinical researchers are interpreting the principle of respect for persons. Our findings invite normative questions about the governance of these practices and sociological questions about whether and how clinical researchers in other professions are also engaging participants in translational research settings.

Chemotherapy and Supportive Care Agents as Essential Medicines for Children With Cancer.

In resource-rich countries, 5-year survival rates for children with cancer approach 85%. This impressive statistic is largely the result of integrating research with clinical care. At the core of this endeavor are multiagent combination chemotherapy and supportive care agents (CASCA). Most CASCAs belong to the class of sterile injectable drugs, which make up the backbone of many proven and life-saving pediatric oncology regimens. There are few if any alternative agents available to treat most life-threatening childhood cancers. In the United States, shortages of CASCAs are now commonplace. The consequences of drug shortages are far reaching. Beyond the economic costs, these shortages directly affect patients' lives, and this is especially true for children with cancer. Drug shortages in general and shortages of CASCAs specifically result in increased medication errors, delayed administration of life-saving therapy, inferior outcomes, and patient deaths. One way to mitigate drug shortages is to adopt an essential medicines list and ensure that these medications remain in adequate supply at all times. We argue for creation of a CASCA-specific essential medicines list for childhood cancer and provide ethical and policy-based reasoning for this approach. We recognize that such a call has implications beyond pediatric cancer, in that children with other serious disease should have an equal claim to access to guaranteed evidence-based medicines. We provide these arguments as an example of what should be claimed for medical indications that are deemed essential to preserve life and function.

A Phase II Study of Alisertib in Children with Recurrent/Refractory Solid Tumors or Leukemia: Children's Oncology Group Phase I and Pilot Consortium (ADVL0921).

PURPOSE: Aurora A kinase (AAK) plays an integral role in mitotic entry, DNA damage checkpoint recovery, and centrosome and spindle maturation. Alisertib (MLN8237) is a potent and selective AAK inhibitor. In pediatric preclinical models, antitumor activity was observed in neuroblastoma, acute lymphoblastic leukemia, and sarcoma xenografts. We conducted a phase 2 trial of alisertib in pediatric patients with refractory or recurrent solid tumors or acute leukemias (NCT01154816). PATIENTS AND METHODS: Alisertib (80 mg/m2/dose) was administered orally, daily for 7 days every 21 days. Pharmacogenomic (PG) evaluation for polymorphisms in the AURK gene and drug metabolizing enzymes (UGT1A1*28), and plasma pharmacokinetic studies (PK) were performed. Using a 2-stage design, patients were enrolled to 12 disease strata (10 solid tumor and 2 acute leukemia). Response was assessed after cycle 1, then every other cycle. RESULTS: A total of 139 children and adolescents (median age, 10 years) were enrolled, 137 were evaluable for response. Five objective responses were observed (2 complete responses and 3 partial responses). The most frequent toxicity was myelosuppression. The median alisertib trough concentration on day 4 was 1.3 µmol/L, exceeding the 1 µmol/L target trough concentration in 67% of patients. No correlations between PG or PK and toxicity were observed. CONCLUSIONS: Despite alisertib activity in pediatric xenograft models and cogent pharmacokinetic-pharmacodynamic relationships in preclinical models and adults, the objective response rate in children and adolescents receiving single-agent alisertib was less than 5%.

A study of axitinib, a VEGF receptor tyrosine kinase inhibitor, in children and adolescents with recurrent or refractory solid tumors: A Children's Oncology Group phase 1 and pilot consortium trial (ADVL1315).

BACKGROUND: Axitinib is an oral small molecule that inhibits receptor tyrosine kinases vascular endothelial growth factor receptors 1 to 3. A phase 1 and pharmacokinetic (PK) trial evaluating axitinib was conducted in children with refractory solid tumors. METHODS: Axitinib was administered orally twice daily in continuous 28-day cycles. Dose levels (2.4 mg/m2 /dose and 3.2 mg/m2 /dose) were evaluated using a rolling 6 design. Serial PKs (cycle 1, days 1 and 8) and exploratory biomarkers were analyzed. RESULTS: A total of 19 patients were enrolled; 1 patient was ineligible due to inadequate time having elapsed from prior therapy. The median age of the patients was 13.5 years (range, 5-17 years). Two of 5 patients who were treated at dose level 2 experienced dose-limiting toxicities (palmar-plantar erythryodysesthesia syndrome in 1 patient and intratumoral hemorrhage in 1 patient). Frequent (>20%) grade 1 to 2 toxicities during cycle 1 included anemia, anorexia, fatigue, diarrhea, nausea, and hypertension. Nonhematological toxicities of grade ≥3 in subsequent cycles included hypertension and elevated serum lipase. PK analysis demonstrated variability in axitinib exposure, the median time to peak plasma concentration was 2 hours, and the half-life ranged from 0.7 to 5.2 hours. Exposure and dose were not found to be significantly associated with hypertension. Five patients achieved stable disease for ≤6 cycles as their best response, including patients with malignant peripheral nerve sheath tumor (1 patient), Ewing sarcoma (1 patient), hepatocellular carcinoma (1 patient), and osteosarcoma (2 patients). One patient with alveolar soft part sarcoma achieved a partial response. Kidney injury biomarkers were found to be elevated at baseline; no trends were identified. CONCLUSIONS: In children with refractory solid tumors, the maximum tolerated and recommended dose of axitinib appears to be 2.4 mg/m2 /dose, which provides PK exposures similar to those of adults.