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PURPOSE: Monoclonal antibodies directed against insulin-like growth factor-1 receptor (IGF-1R) have shown activity in patients with relapsed Ewing sarcoma. The primary objective of Childrens Oncology Group trial AEWS1221 was to determine if the addition of the IGF-1R monoclonal antibody ganitumab to interval-compressed chemotherapy improves event-free survival (EFS) in patients with newly diagnosed metastatic Ewing sarcoma. METHODS: Patients were randomly assigned 1:1 at enrollment to standard arm (interval-compressed vincristine/doxorubicin/cyclophosphamide alternating once every 2 weeks with ifosfamide/etoposide = VDC/IE) or to experimental arm (VDC/IE with ganitumab at cycle starts and as monotherapy once every 3 weeks for 6 months after conventional therapy). A planned sample size of 300 patients was projected to provide 81% power to detect an EFS hazard ratio of 0.67 or smaller for the experimental arm compared with the standard arm with a one-sided α of .025. RESULTS: Two hundred ninety-eight eligible patients enrolled (148 in standard arm; 150 in experimental arm). The 3-year EFS estimates were 37.4% (95% CI, 29.3 to 45.5) for the standard arm and 39.1% (95% CI, 31.3 to 46.7) for the experimental arm (stratified EFS-event hazard ratio for experimental arm 1.00; 95% CI, 0.76 to 1.33; 1-sided, P = .50). The 3-year overall survival estimates were 59.5% (95% CI, 50.8 to 67.3) for the standard arm and 56.7% (95% CI, 48.3 to 64.2) for the experimental arm. More cases of pneumonitis after radiation involving thoracic fields and nominally higher rates of febrile neutropenia and ALT elevation were reported on the experimental arm. CONCLUSION: Ganitumab added to interval-compressed chemotherapy did not significantly reduce the risk of EFS event in patients with newly diagnosed metastatic Ewing sarcoma, with outcomes similar to prior trials without IGF-1R inhibition or interval compression. The addition of ganitumab may be associated with increased toxicity.

PURPOSE: To identify potential clinical prognostic factors associated with a higher risk of local recurrence in patients with localized pelvic Ewing sarcoma treated with radiation therapy. METHODS AND MATERIALS: Data for 101 patients treated with definitive radiation therapy (RT) or both surgery and radiation (S + RT) to primary pelvic tumors on INT-0091, INT-0154, and AEWS0031 were analyzed. Imaging data for patients who did not receive radiation were not available for central review; therefore, patients with surgery alone were not included. Cumulative incidence rates for local failure at 5 years from time of local control were calculated accounting for competing risks. RESULTS: The most common pelvic subsite was sacrum (44.6%). RT was used in 68% of patients and S + RT in 32%. The local failure rate was 25.0% for RT and 6.3% for S + RT (P = .046). There was no statistically significant difference in local control modality by tumor characteristics. Tumors originating in the ischiopubic-acetabulum region were associated with the highest local failure incidence, 37.5% (P = .02, vs sacrum and iliac/buttock tumors), particularly those treated with RT (50.0%, P = .06). A higher incidence of local failure was seen with each additional 100 mL of tumor at diagnosis (P = .04). Multivariable analysis demonstrated RT alone (hazard ratio [HR], 5.1; P = .04), tumor subsite (particularly ischiopubic-acetabulum tumors; HR 4.6; P = .02), and increasing volume per 100 mL (HR, 1.2; P = .01) were associated with a higher incidence of local recurrence. CONCLUSIONS: Combination surgery and RT is associated with improved local control in patients with pelvic Ewing sarcoma compared with definitive RT. Tumors involving the ischiopubic-acetabulum region and increasing tumor volume at diagnosis are associated with inferior local control. Tumor characteristics did not correlate with choice of local therapy modality suggesting an opportunity to develop best local therapy practices guidelines for future studies based on tumor features.

PURPOSE: Novel effective therapies are urgently needed in recurrent osteosarcoma. GD2 is expressed in human osteosarcoma tumours and cell lines. This study evaluated the disease control rate (DCR) in patients with recurrent osteosarcoma treated with the anti-GD2 antibody dinutuximab plus cytokine therapy as compared to historical outcomes. METHODS: AOST1421 was a single-arm Phase 2 study for patients with recurrent pulmonary osteosarcoma in complete surgical remission. Patients received up to five cycles of dinutuximab (70 mg/m2/cycle) with granulocyte-macrophage colony-stimulating factor (GM-CSF). Two different dinutuximab infusion schedules were studied: 35 mg/m2/day over 20 h (2 days) and 17.5 mg/m2/day over 10 h (4 days). Primary end point was DCR, defined as a proportion of patients event free at 12 months from enrolment. The historical benchmark was 12-month DCR of 20% (95% CI 10-34%). Dinutuximab would be considered effective if ≥ 16/39 patients remained event free. Secondary objectives included toxicity evaluation and pharmacokinetics. RESULTS: Thirty-nine eligible patients were included in the outcome analysis. Dinutuximab did not demonstrate evidence of efficacy as 11/39 patients remained event free for a DCR of 28.2% (95% CI 15-44.9%). One of 136 administered therapy cycles met criteria for unacceptable toxicity when a patient experienced sudden death of unknown cause. Other ≥ Grade 3 toxicities included pain, diarrhoea, hypoxia, and hypotension. Pharmacokinetic parameters were similar in the two schedules. CONCLUSIONS: The combination of dinutuximab with GM-CSF did not significantly improve DCR in recurrent osteosarcoma. Dinutuximab toxicity and pharmacokinetics in adolescent and young adult osteosarcoma patients were similar to younger patients. Other strategies for targeting GD2 in osteosarcoma are being developed.

PurposeThe primary aim of this phase III randomized trial was to test whether the addition of vincristine, topotecan, and cyclophosphamide (VTC) to interval compressed chemotherapy improved survival outcomes for patients with previously untreated nonmetastatic Ewing sarcoma.MethodsPatients were randomly assigned to receive standard five-drug interval compressed chemotherapy (regimen A) for 17 cycles or experimental therapy with five cycles of VTC within the 17 cycles (regimen B). Patients were stratified by age at diagnosis (< 18 years and ≥18 years) and tumor site (pelvic bone, nonpelvic bone, and extraosseous). Tumor volume at diagnosis was categorized as < 200 mL or ≥ 200 mL. Local control occurred following six cycles. Histologic response was categorized as no viable or any viable tumor. Event-free survival (EFS) and overall survival (OS) were compared between randomized groups with stratified log-rank tests.ResultsOf 642 enrolled patients, 309 eligible patients received standard and 320 received experimental therapy. The 5-year EFS and OS were 78% and 87%, respectively. There was no difference in survival outcomes between randomized groups (5-year EFS regimen A v regimen B, 78% v 79%; P = .192; 5-year OS 86% v 88%; P = .159). Age and primary site did not affect the risk of an EFS event. However, age ≥ 18 years was associated with an increased risk of death at 5 years (hazard ratio 1.84; 95% CI, 1.15 to 2.96; P = .009). The 5-year EFS rates for patients with pelvic, nonpelvic bone, and extraosseous primary tumors were 75%, 78%, and 85%, respectively. Tumor volume ≥ 200 mL was significantly associated with lower EFS.ConclusionWhile VTC added to five-drug interval compressed chemotherapy did not improve survival, these outcomes represent the best survival estimates to date for patients with previously untreated nonmetastatic Ewing sarcoma.

PurposeThe R2Pulm trial was conducted to evaluate the effect of busulfan-melphalan high-dose chemotherapy with autologous stem-cell rescue (BuMel) without whole-lung irradiation (WLI) on event-free survival (main end point) and overall survival, compared with standard chemotherapy with WLI in Ewing sarcoma (ES) presenting with pulmonary and/or pleural metastases.MethodsFrom 2000 to 2015, we enrolled patients younger than 50 years of age with newly diagnosed ES and with only pulmonary or pleural metastases. Patients received chemotherapy with six courses of vincristine, ifosfamide, doxorubicin, and etoposide (VIDE) and one course of vincristine, dactinomycin, and ifosfamide (VAI) before either BuMel or seven courses of VAI and WLI (VAI plus WLI) by randomized assignment. The analysis was conducted as intention to treat. The estimates of the hazard ratio (HR), 95% CI, and P value were corrected for the three previous interim analyses by the inverse normal method.ResultsOf 543 potentially eligible patients, 287 were randomly assigned to VAI plus WLI (n = 143) or BuMel (n = 144). Selected patients requiring radiotherapy to an axial primary site were excluded from randomization to avoid excess organ toxicity from interaction between radiotherapy and busulfan. Median follow-up was 8.1 years. We did not observe any significant difference in survival outcomes between treatment groups. Event-free survival was 50.6% versus 56.6% at 3 years and 43.1% versus 52.9% at 8 years, for VAI plus WLI and BuMel patients, respectively, resulting in an HR of 0.79 (95% CI, 0.56 to 1.10; P = .16). For overall survival, the HR was 1.00 (95% CI, 0.70 to 1.44; P = .99). Four patients died as a result of BuMel-related toxicity, and none died after VAI plus WLI. Significantly more patients in the BuMel arm experienced severe acute toxicities than in the VAI plus WLI arm.ConclusionIn ES with pulmonary or pleural metastases, there is no clear benefit from BuMel compared with conventional VAI plus WLI.

BackgroundPatients with recurrent or refractory osteosarcoma have a poor prognosis with less than 30% surviving two years. Eribulin is a synthetic analog of halichondrin B, has a novel mechanism of action when compared with other microtubule inhibitors, and may have antitumor activity in osteosarcoma.MethodsA prospective study was designed to assess the disease control success at four months and objective response rates in patients with recurrent or refractory osteosarcoma treated with eribulin. Eligible patients were between 12 and 50 years of age, had measurable tumor, and met standard organ function requirements. Patients were given eribulin 1.4 mg/m2 /dose on days 1 and 8 of each 3-week cycle for up to 24 months if there was no progressive disease. Response to therapy was assessed using RECIST 1.1 criteria after cycles 2 and 5 and every fourth cycle thereafter.ResultsNineteen patients enrolled on the AOST1322 study. The median age of enrollment was 16 years (range, 12-25 years). Twelve patients were male and seven female. Eribulin was well tolerated, with neutropenia identified as the most common toxicity. The median progression-free survival was 38 days and no patients reached the four-month time point without progression. No objective responses were seen in any patient.ConclusionThis study rapidly assessed the clinical activity of a novel agent in this patient population. Eribulin was well tolerated, but there were no patients who demonstrated objective response, and all patients had progression prior to four months.

PurposeTo identify clinical and treatment variables associated with a higher risk of local failure in Ewing sarcoma patients treated on recent Children's Oncology Group protocols.Methods and materialsData for 956 patients treated with ifosfamide and etoposide-based chemotherapy on INT-0091, INT-0154, and AEWS0031 were analyzed. Local treatment modalities were defined as surgery, definitive radiation therapy (RT), or surgery plus radiation (S+RT). Five-year cumulative incidence of local failure was determined.ResultsThe local failure rate for the entire cohort was 7.3%, with a 3.9% rate for surgery, 15.3% for RT (P

BackgroundThe choice of a local control (LC) modality for Ewing sarcoma (EWS) of the femur is controversial. This study aimed to determine the effect of LC modality on tumor LC and patient outcomes.MethodsThe study reviewed the treatment and outcomes for 115 patients who had EWS of the femur treated with similar chemotherapy in three cooperative group trials. Patient outcomes were analyzed according to the LC modality using the log-rank test and the cumulative incidence of local or distant failure using competing risks regression.ResultsThe median age of the patients was 13 years. The most common tumor location was the proximal femur followed by the mid femur. For 55 patients with available data, the tumor was larger than 8 cm in 29 patients and 8 cm or smaller in 26 patients. For 84 patients (73 %), surgery only was performed, whereas 17 patients (15 %) had surgery plus radiation, and 14 patients (12 %) had radiation only. The 5-year event-free survival (EFS) rate was 65 % (95 % confidence interval [CI], 55-73 %), and the 5-year overall survival (OS) rate was 70 % (95 % CI, 61-78 %). Patient outcomes did not differ significantly according to tumor location within the femur (proximal, mid or distal) or tumor size (

PurposeFlow cytometry and RT-PCR can detect occult Ewing sarcoma cells in the blood and bone marrow. These techniques were used to evaluate the prognostic significance of micrometastatic disease in Ewing sarcoma.Experimental designNewly diagnosed patients with Ewing sarcoma were enrolled on two prospective multicenter studies. In the flow cytometry cohort, patients were defined as "positive" for bone marrow micrometastatic disease if their CD99(+)/CD45(-) values were above the upper limit in 22 control patients. In the PCR cohort, RT-PCR on blood or bone marrow samples classified the patients as "positive" or "negative" for EWSR1/FLI1 translocations. The association between micrometastatic disease burden with clinical features and outcome was assessed. Coexpression of insulin-like growth factor-1 receptor (IGF-1R) on detected tumor cells was performed in a subset of flow cytometry samples.ResultsThe median total bone marrow CD99(+)CD45(-) percent was 0.0012% (range 0%-1.10%) in the flow cytometry cohort, with 14 of 109 (12.8%) of Ewing sarcoma patients defined as "positive." In the PCR cohort, 19.6% (44/225) patients were "positive" for any EWSR1/FLI1 translocation in blood or bone marrow. There were no differences in baseline clinical features or event-free or overall survival between patients classified as "positive" versus "negative" by either method. CD99(+)CD45(-) cells had significantly higher IGF-1R expression compared with CD45(+) hematopoietic cells (mean geometric mean fluorescence intensity 982.7 vs. 190.9; P < 0.001).ConclusionsThe detection of micrometastatic disease at initial diagnosis by flow cytometry or RT-PCR is not associated with outcome in newly diagnosed patients with Ewing sarcoma. Flow cytometry provides a tool to characterize occult micrometastatic tumor cells for proteins of interest. Clin Cancer Res; 22(14); 3643-50. ©2016 AACR.

BackgroundAlthough multiple prognostic variables have been proposed for Ewing sarcoma (EWS), little work has been done to further categorize these variables into prognostic groups for risk classification.ProcedureWe derived initial prognostic groups from 2,124 patients with EWS in the SEER database. We constructed a multivariable recursive partitioning model of overall survival using the following covariates: age; stage; race/ethnicity; sex; axial primary; pelvic primary; and bone or soft tissue primary. Based on this model, we identified risk groups and estimated 5-year overall survival for each group using Kaplan-Meier methods. We then applied these groups to 1,680 patients enrolled on COG clinical trials.ResultsA multivariable model identified five prognostic groups with significantly different overall survival: (i) localized, age

BackgroundA growing collection of retrospective studies have suggested that TP53 mutations and/or CDKN2A deletions have prognostic significance in Ewing sarcoma. We sought to evaluate these variables in patients with localized disease treated prospectively on a single Children's Oncology Group protocol.ProcedureOf the 568 patients enrolled on Children's Oncology Group protocol AEWS0031 (NCT00006734), 112 had tumor specimens of sufficient quality and quantity to allow for analysis of TP53 mutations status by DNA sequencing, and CDKN2A deletion by dual color fluorescent in situ hybridization.ResultsEight of 93 cases (8.6%) were found to have TP53 point mutations and 12 of 107 cases (11.2%) demonstrated homozygous CDKN2A deletion. Two cases were found to have an alteration in both genes. There was no significant difference in event-free survival of patients with TP53 mutations and/or CDKN2A deletions compared to patients with normal TP53/CDKN2A gene status, as demonstrated by log rank test (p = 0.58).ConclusionsAlthough previous retrospective studies suggest their significance, TP53 mutation and/or CDKN2A deletion are not reliable prognostic biomarkers in localized Ewing sarcoma.

BackgroundPatients with Ewing sarcoma require local primary tumor control with surgery, radiation, or both. The optimal choice of local control for overall and local disease control remains unclear.MethodsPatients with localized Ewing sarcoma of bone who were treated on 3 consecutive protocols with standard-dose, 5-drug chemotherapy every 3 weeks were included (n=465). Propensity scores were used to control for differences between local control groups by constructing multivariate models to assess the impact of local control type on clinical endpoints (event-free survival [EFS], overall survival, local failure, and distant failure) independent of differences in their propensity to receive each local control type.ResultsPatients who underwent surgery were younger (P=.02) and had more appendicular tumors (P

BackgroundThe genetics involved in Ewing sarcoma susceptibility and prognosis are poorly understood. EWS/FLI and related EWS/ETS chimeras upregulate numerous gene targets via promoter-based GGAA-microsatellite response elements. These microsatellites are highly polymorphic in humans, and preliminary evidence suggests EWS/FLI-mediated gene expression is highly dependent on the number of GGAA motifs within the microsatellite.ObjectivesHere we sought to examine the polymorphic spectrum of a GGAA-microsatellite within the NR0B1 promoter (a critical EWS/FLI target) in primary Ewing sarcoma tumors, and characterize how this polymorphism influences gene expression and clinical outcomes.ResultsA complex, bimodal pattern of EWS/FLI-mediated gene expression was observed across a wide range of GGAA motifs, with maximal expression observed in constructs containing 20-26 GGAA motifs. Relative to white European and African controls, the NR0B1 GGAA-microsatellite in tumor cells demonstrated a strong bias for haplotypes containing 21-25 GGAA motifs suggesting a relationship between microsatellite function and disease susceptibility. This selection bias was not a product of microsatellite instability in tumor samples, nor was there a correlation between NR0B1 GGAA-microsatellite polymorphisms and survival outcomes.ConclusionsThese data suggest that GGAA-microsatellite polymorphisms observed in human populations modulate EWS/FLI-mediated gene expression and may influence disease susceptibility in Ewing sarcoma.

PurposeChemotherapy with alternating vincristine-doxorubicin-cyclophosphamide and ifosfamide-etoposide cycles and primary tumor treatment with surgery and/or radiation therapy constitute the usual approach to localized Ewing sarcoma in North America. We tested whether chemotherapy intensification through interval compression could improve outcome.Patients and methodsThis was a prospective, randomized controlled trial for patients younger than 50 years old with newly diagnosed localized extradural Ewing sarcoma. Patients assigned to standard and intensified treatment were to begin chemotherapy cycles every 21 and 14 days, respectively, provided an absolute neutrophil count greater than 750×10(6)/L and a platelet count greater than 75×10(9)/L. Patients received vincristine (2 mg/m2), doxorubicin (75 mg/m2), and cyclophosphamide (1.2 g/m2) alternating with ifosfamide (9 g/m2) and etoposide (500 mg/m2) for 14 cycles, with filgrastim (5 mg/kg per day; maximum, 300 mg) between cycles. Primary tumor treatment (surgery, radiation, or both) was to begin at week 13 (after four cycles in the standard arm and six cycles in the intensified arm). The primary end point was event-free survival (EFS). The study is registered at ClinicalTrials.gov (identifier: NCT00006734).ResultsFive hundred eighty-seven patients were enrolled and randomly assigned, and 568 patients were eligible, with 284 patients in each regimen. For all cycles, the median cycle interval for standard treatment was 21 days (mean, 22.45 days); for intensified treatment, the median interval was 15 days (mean, 17.29 days). EFS at a median of 5 years was 65% in the standard arm and 73% in the intensified arm (P=.048). The toxicity of the regimens was similar.ConclusionFor localized Ewing sarcoma, chemotherapy administered every 2 weeks is more effective than chemotherapy administered every 3 weeks, with no increase in toxicity.