Yoga as a non-pharmacologic therapy to reduce dinutuximab-induced pain in patients with neuroblastoma

BACKGROUND

Anti-GD2 antibodies are key components of treatment for high-risk neuroblastoma; however, they cause neuropathic pain. Yoga therapy may help reduce pain and distress associated with anti-GD2 therapy.

PROCEDURE

Children 3 years of age or older with neuroblastoma participated in individualized yoga therapy while receiving the anti-GD2 antibody dinutuximab (DIN). Yoga therapy was deemed feasible if patients participated during 60% or more of DIN admissions. Patients and caregivers assessed pain/distress before and after yoga therapy with a distress thermometer (DT) and Wong-Baker FACES pain rating scale and completed questionnaires regarding satisfaction with yoga therapy. Therapy was deemed efficacious if there was a ≥1 point pain score change and reduction in distress after yoga.

RESULTS

Eighteen patients were enrolled; 52 encounters (admissions for DIN) were evaluable. Ten of 18 were female, three of 18 were Hispanic, and 10/18 were White. Median age at enrollment was 5.5 years (range: 3-11). Yoga therapy was feasible in 39/52 (75%) encounters. Significant reductions in caregiver-reported pain and distress and reductions in patient-reported pain and distress after yoga therapy were reported. Twelve of 18 caregivers completed questionnaires: seven agreed/strongly agreed that yoga was valuable, and nine agreed/strongly agreed to continued participation in yoga. Thirty-four of 36 clinicians reported that they would recommend yoga therapy for other patients receiving DIN.

CONCLUSIONS

Yoga therapy was feasible during DIN therapy and may be effective in reducing DIN-associated pain and distress. Future studies are needed to evaluate changes in opioid usage with the addition of yoga therapy during anti-GD2 antibody therapy.

Factors influencing parents' choice of palliative treatment goals for children with relapsed or refractory neuroblastoma: A multi-site longitudinal survey study

BACKGROUND

Many parents of children with advanced cancer report curative goals and continue intensive therapies that can compound symptoms and suffering. Factors that influence parents to choose palliation as the primary treatment goal are not well understood. The objective of this study was to examine experiences impacting parents' report of palliative goals adjusted for time. The authors hypothesized that awareness of poor prognosis, recall of oncologists' prognostic disclosure, intensive treatments, and burdensome symptoms and suffering would influence palliative goal-setting.

METHODS

The authors collected prospective, longitudinal surveys from parents of children with relapsed/refractory neuroblastoma at nine pediatric cancer centers across the United States, beginning at relapse and continuing every 3 months for 18 months or until death. Hypothesized covariates were examined for possible associations with parental report of palliative goals. Generalized linear mixed models were used to evaluate factors associated with parents' report of palliative goals at different time points.

RESULTS

A total of 96 parents completed surveys. Parents were more likely to report a primary goal of palliation when they recalled communication about prognosis by their child's oncologist (odds ratio [OR], 52.48; p = .010). Treatment intensity and previous ineffective therapeutic regimens were not associated with parents' report of palliative goals adjusted for time. A parent who reported new suffering for their child was less likely to report palliative goals (OR, 0.13; p = .008).

CONCLUSIONS

Parents of children with poor prognosis cancer may not report palliative goals spontaneously in the setting of treatment-related suffering. Prognostic communication, however, does influence palliative goal-setting. Evidence-based interventions are needed to encourage timely, person-centered prognostic disclosure in the setting of advanced pediatric cancer.

PLAIN LANGUAGE SUMMARY

Many parents of children with poor-prognosis cancer continue to pursue curative treatments that may worsen symptoms and suffering. Little is known about which factors influence parents to choose palliative care as their child's main treatment goal. To explore this question, we asked parents of children with advanced neuroblastoma across the United States to complete multiple surveys over time. We found that the intensity of treatment, number of treatments, and suffering from treatment did not influence parents to choose palliative goals. However, when parents remembered their child's oncologist talking about prognosis, they were more likely to choose palliative goals of care.

Percutaneous biopsy for the diagnosis, risk stratification, and molecular profiling of neuroblastoma: A single-center retrospective study

PURPOSE

To determine whether percutaneous core needle biopsy (PCNB) is adequate for the diagnosis and full molecular characterization of newly diagnosed neuroblastoma.

MATERIALS AND METHODS

Patients with newly diagnosed neuroblastoma who underwent PCNB in interventional radiology at a single center over a 5-year period were included. Pre-procedure imaging and procedure details were reviewed. Rates of diagnostic success and sufficiency for International Neuroblastoma Pathology Classification (INPC), risk stratification, and evaluation of genomic markers utilized in the Children's Oncology Group risk stratification, and status of the anaplastic lymphoma kinase (ALK) gene were assessed.

RESULTS

Thirty-five patients (13 females, median age 2.4 years [interquartile range, IQR: 0.9-4.4] and median weight 12.4 kg [IQR: 9.6-18]) were included. Most had International Neuroblastoma Risk Group Stage M disease (n = 22, 63%). Median longest axis of tumor target was 8.8 cm [IQR: 6.1-12]. A 16-gauge biopsy instrument was most often used (n = 20, 57%), with a median of 20 cores [IQR: 13-23] obtained. Twenty-five specimens were assessed for adequacy, and 14 procedures utilized contrast-enhanced ultrasound guidance. There were two post-procedure bleeds (5.7%). Thirty-four of 35 procedures (97%) were sufficient for histopathologic diagnosis and risk stratification, 94% (n = 32) were sufficient for INPC, and 85% (n = 29) were sufficient for complete molecular characterization, including ALK testing. Biologic information was otherwise obtained from bone marrow (4/34, 12%) or surgery (1/34, 2.9%). The number of cores did not differ between patients with sufficient versus insufficient biopsies.

CONCLUSION

In this study, obtaining multiple cores with PCNB resulted in a high rate of diagnosis and successful molecular profiling for neuroblastoma.

Survival and Local Recurrence Risk in Patients with High-Risk Neuroblastoma Treated with Proton Therapy over a 10 Year Interval

PURPOSE/OBJECTIVE(S)

Patients (pts) with high-risk neuroblastoma (HR-NBL) require radiation (RT) to the primary tumor site (PS); approach is standardized within North American paradigms but remains a subject of global study. Long-term experience using proton therapy (PRT) in this population is lacking. We hypothesized that PRT would be associated with low risk of local recurrence (LR) in a large population of pts with HR-NBL spanning > 10 years.

MATERIALS/METHODS

Sequential pts with HR-NBL at a single institution received RT to PS and persistent metastatic sites (MS). Dose to PS after subtotal resection (STR) was reduced from 36 Gy to 21.6 Gy in 2019 based on results from the Children's Oncology Group ANBL0532 trial (Liu K, 2019). Analysis using Kaplan Meier method and log rank test was performed with IRB approval.

RESULTS

From 9/2010 - 12/2021, 99 pts with HR-NBL received PS RT during first-line therapy; most [78, (79%)] had adrenal primary tumors and 26 (26%) received MS RT. Median age was 48m at RT (R 11m to 17.5y) and 52 (53%) were female. All pts had multi-agent induction chemotherapy (CT) [+ dinutuximab [12 (13%)] and/ or therapeutic 131MIBG [19 (19%)] and resection of primary tumor prior to RT; 34 (34%) patients had STR with residual disease (RD) on post-op imaging, 65 (66%) had gross total resection (GTR). Dose to PS was 21.6 Gy for 78 (79%) pts and 36 Gy for 21 (21%) based on RD and treatment era; PRT was pencil beam [78 (79%)] or double scattered [22 (22%)], combined with IMRT in 2 (2%). With median FU of 4.2 yrs (R 0.5y - 12y), 80 pts (81%) are alive [66 (67%) disease-free, 14 (14%) with disease], 19 (19%) have died. Progressive disease (PD) occurred in 33 (33%), with median time to PD 24m (R 8-116m); two pts (2%) had isolated LR, 25 (25%) distant PD, and 6 (6%) concurrent LR and distant PD. Risk of LR at 10 years was 8%; absolute risk of any LR was 8% (6/78) in 21.6 Gy cohort and 9% (2/21) in 36 Gy cohort (p = NS). After induction CT, 34 (34%) pts had STR with > 1cm3 RD on axial imaging; 18/ 34 (53%) also had MIBG uptake (MIBG+) at PS. Based on treatment era, 21 pts (62%) after STR received 21.6 Gy + boost to RD (36 Gy), and 13 (38%) 21.6 alone. Of those who received 36 Gy (median FU 5.7y), 2/21 (9.5%) had LR with concurrent distant PD; of those who received 21.6 Gy (median FU 3.2y) 4/13 (31%) had LR (2 with concurrent distant PD and 2 LR only) (p = 0.03). In the 21.6 Gy GTR cohort, 2/65 (3%) had LR + distant PD. Of 8 total patients who experienced LR, 5 had MIBG + RD, 1 MIBG- RD, and 2 GTR.

CONCLUSION

We observed excellent outcomes in 99 pts treated with proton radiotherapy for HR-NBL from 2010 through 2021, with 81% of patients alive and 92% free of LR. Our data suggest that LR is rare after GTR and 21.6 Gy, and uncommon among pts with STR treated with 36 Gy. A small number of pts received 21.6 Gy after STR, however, this experience suggests that a subset of pts with RD may require RT dose > 21.6 Gy. Further work is required to further characterize individual management of PS in pts with HR-NBL with regard to extent of RD and biologic disease features.

Children's Oncology Group's 2023 blueprint for research: Neuroblastoma

Neuroblastoma is the most common extra-cranial solid tumor in children and is known for its clinical heterogeneity. A greater understanding of the biology of this disease has led to both improved risk stratification and new approaches to therapy. Outcomes for children with low and intermediate risk disease are excellent overall, and efforts to decrease therapy for such patients have been largely successful. Although survival has improved over time for patients with high-risk disease and treatments evaluated in the relapse setting are now being moved into earlier phases of treatment, much work remains to improve survival and decrease therapy-related toxicities. Studies of highly annotated biobanked samples continue to lead to important insights regarding neuroblastoma biology. Such studies, along with correlative biology studies incorporated into therapeutic trials, are expected to continue to provide insights that lead to new and more effective therapies. A focus on translational science is accompanied by an emphasis on new agent development, optimized risk stratification, and international collaboration to address questions relevant to molecularly defined subsets of patients. In addition, the COG Neuroblastoma Committee is committed to addressing the patient/family experience, mitigating late effects of therapy, and studying social determinants of health in patients with neuroblastoma.

Impact of diagnostic and end-of-induction Curie scores with tandem high-dose chemotherapy and autologous transplants for metastatic high-risk neuroblastoma: A report from the Children's Oncology Group

BACKGROUND

Diagnostic mIBG (meta-iodobenzylguanidine) scans are an integral component of response assessment in children with high-risk neuroblastoma. The role of end-of-induction (EOI) Curie scores (CS) was previously described in patients undergoing a single course of high-dose chemotherapy (HDC) and autologous hematopoietic cell transplant (AHCT) as consolidation therapy.

OBJECTIVE

We now examine the prognostic significance of CS in patients randomized to tandem HDC and AHCT on the Children's Oncology Group (COG) trial ANBL0532.

STUDY DESIGN

A retrospective analysis of mIBG scans obtained from patients enrolled in COG ANBL0532 was performed. Evaluable patients had mIBG-avid, International Neuroblastoma Staging System (INSS) stage 4 disease, did not progress during induction therapy, consented to consolidation randomization, and received either single or tandem HDC (n = 80). Optimal CS cut points maximized the outcome difference (≤CS vs. >CS cut-off) according to the Youden index.

RESULTS

For recipients of tandem HDC, the optimal cut point at diagnosis was CS = 12, with superior event-free survival (EFS) from study enrollment for patients with CS ≤ 12 (3-year EFS 74.2% ± 7.9%) versus CS > 12 (59.2% ± 7.1%) (p = .002). At EOI, the optimal cut point was CS = 0, with superior EOI EFS for patients with CS = 0 (72.9% ± 6.4%) versus CS > 0 (46.5% ± 9.1%) (p = .002).

CONCLUSION

In the setting of tandem transplantation for children with high-risk neuroblastoma, CS at diagnosis and EOI may identify a more favorable patient group. Patients treated with tandem HDC who exhibited a CS ≤ 12 at diagnosis or CS = 0 at EOI had superior EFS compared to those with CS above these cut points.

Systematic review of clinical drug development activities for neuroblastoma from 2011 to 2020

BACKGROUND

Understanding the landscape of clinical trials for patients with neuroblastoma may inform efforts to improve drug development.

PROCEDURE

We evaluated therapeutic trials for patients with neuroblastoma from 2011 to 2020 in our search using clinical trial information from ClinicalTrials.gov, Clinicaltrialregister.eu, PubMed, and American Society of Clinical Oncology (ASCO) annual meeting collection. Trends in trials and treatments over time were evaluated qualitatively.

RESULTS

A total of 192 trials met inclusion criteria. A median of 20.5 trials were started per year, which was stable over time. There were 87 (45%) phase 1, 100 (51%) phase 2, and only five (2.6%) phase 3 trials. The median time to completion was 4.9 years for phase 1 and 2 trials (no phase 3 trials reported as completed during the study period). In all, 34% of trials were international, while 20% of trials were intercontinental. Eighty-nine percent of nonmyeloablative trials included at least one novel agent. 48% of these trials studied combination therapies, and 86% of these combinations included conventional chemotherapy. Among 157 trials that included a targeted agent, 78 targets were identified, with GD2 being the primary target under investigation in 16.7% of these trials. Only eight trials were included in regulatory decisions, which led to European Medicines Agency (EMA) or Food and Drug Administration (FDA) approval for neuroblastoma.

CONCLUSIONS

The large number of trials initiated per year, the range of targets, and the rate of intercontinental collaboration are encouraging. The paucity of late-stage trials, the prolonged trial duration, and relative lack of combination studies are major causes of concern. This work will inform future drug development for neuroblastoma.

Impact of Genomic and Clinical Factors on Outcome of Children ≥18 Months of Age with Stage 3 Neuroblastoma with Unfavorable Histology and without MYCN Amplification: A Children's Oncology Group (COG) Report

PURPOSE

Patients ≥18 months of age with International Neuroblastoma Staging System (INSS) stage 3 unfavorable histology (UH), MYCN-nonamplified (MYCN-NA) tumors have favorable survival rates compared with other high-risk neuroblastoma populations. The impact of select clinical and biological factors on overall survival (OS) and event-free survival (EFS) were evaluated.

EXPERIMENTAL DESIGN

Patients enrolled on Children's Oncology Group (COG) A3973 (n = 34), ANBL0532 (n = 27), and/or biology protocol ANBL00B1 (n = 72) were analyzed. Tumors with available DNA (n = 65) and RNA (n = 42) were subjected to whole-exome sequencing (WES) and RNA sequencing. WES analyses and gene expression profiling were evaluated for their impact on survival. Multivariate analyses of EFS/OS using significant factors from univariate analyses were performed.

RESULTS

5-year EFS/OS for patients treated with high-risk therapy on A3973 and ANBL0532 were 73.0% ± 8.1%/87.9% ± 5.9% and 61.4% ± 10.2%/73.0% ± 9.2%, respectively (P = 0.1286 and P = 0.2180). In the A3973/ANBL0532 cohort, patients with less than partial response (PR; n = 5) at end-induction had poor outcomes (5-year EFS/OS: 0%/20.0% ± 17.9%. Univariate analyses of WES data revealed that subjects whose tumors had chromosome 1p or 11q loss/LOH and chromosome 5 or 9 segmental chromosomal aberrations had inferior EFS compared with those with tumors without these aberrations. Multivariate analysis revealed that 11q loss/LOH was an independent predictor of inferior OS [HR, 3.116 (95% confidence interval, 1.034-9.389), P = 0.0435].

CONCLUSIONS

Patients ≥18 months of age at diagnosis who had tumors with UH and MYCN-NA INSS stage 3 neuroblastoma assigned to high-risk therapy had an 81.6% ± 5.3% 5-year OS. Less than PR to induction therapy and chromosome 11q loss/LOH are independent predictors of inferior outcome and identify patients who should be eligible for future high-risk clinical trials.

Neuroblastic Tumor Recurrence Associated With Opsoclonus Myoclonus Ataxia Syndrome Relapse a Decade After Initial Resection and Treatments

Opsoclonus myoclonus ataxia syndrome (OMAS) is a rare disorder that causes significant neurodevelopmental sequelae in children. Approximately half of pediatric OMAS cases are paraneoplastic, typically associated with localized neuroblastic tumors. Since early persistence or relapse of OMAS symptoms is common even after tumor resection, OMAS relapses may not routinely prompt reevaluation for recurrent tumors. We report a 12-year-old girl with neuroblastic tumor recurrence associated with OMAS relapse a decade after initial treatment. Providers should be aware of tumor recurrence as a trigger for distant OMAS relapse, raising intriguing questions about the role of immune surveillance and control of neuroblastic tumors.

KIR/KIR-ligand genotypes and clinical outcomes following chemoimmunotherapy in patients with relapsed or refractory neuroblastoma: a report from the Children's Oncology Group

BACKGROUND

In the Children's Oncology Group ANBL1221 phase 2 trial for patients with first relapse/first declaration of refractory high-risk neuroblastoma, irinotecan and temozolomide (I/T) combined with either temsirolimus (TEMS) or immunotherapy (the anti-GD2 antibody dinutuximab (DIN) and granulocyte macrophage colony stimulating factory (GM-CSF)) was administered. The response rate among patients treated with I/T/DIN/GM-CSF in the initial cohort (n=17) was 53%; additional patients were enrolled to permit further evaluation of this chemoimmunotherapy regimen. Potential associations between immune-related biomarkers and clinical outcomes including response and survival were evaluated.

METHODS

Patients were evaluated for specific immunogenotypes that influence natural killer (NK) cell activity, including killer immunoglobulin-like receptors (KIRs) and their ligands, Fc gamma receptors, and NCR3. Total white cells and leucocyte subsets were assessed via complete blood counts, and flow cytometry of peripheral blood mononuclear cells was performed to assess the potential association between immune cell subpopulations and surface marker expression and clinical outcomes. Appropriate statistical tests of association were performed. The Bonferroni correction for multiple comparisons was performed where indicated.

RESULTS

Of the immunogenotypes assessed, the presence or absence of certain KIR and their ligands was associated with clinical outcomes in patients treated with chemoimmunotherapy rather than I/T/TEMS. While median values of CD161, CD56, and KIR differed in responders and non-responders, statistical significance was not maintained in logistic regression models. White cell and neutrophil counts were associated with differences in survival outcomes, however, increases in risk of event in patients assigned to chemoimmunotherapy were not clinically significant.

CONCLUSIONS

These findings are consistent with those of prior studies showing that KIR/KIR-ligand genotypes are associated with clinical outcomes following anti-GD2 immunotherapy in children with neuroblastoma. The current study confirms the importance of KIR/KIR-ligand genotype in the context of I/T/DIN/GM-CSF chemoimmunotherapy administered to patients with relapsed or refractory disease in a clinical trial. These results are important because this regimen is now widely used for treatment of patients at time of first relapse/first declaration of refractory disease. Efforts to assess the role of NK cells and genes that influence their function in response to immunotherapy are ongoing.

TRIAL REGISTRATION NUMBER

NCT01767194.

Progression-Free Survival and Patterns of Response in Patients With Relapsed High-Risk Neuroblastoma Treated With Irinotecan/Temozolomide/Dinutuximab/Granulocyte-Macrophage Colony-Stimulating Factor

PURPOSE

Although chemoimmunotherapy is widely used for treatment of children with relapsed high-risk neuroblastoma (HRNB), little is known about timing, duration, and evolution of response after irinotecan/temozolomide/dinutuximab/granulocyte-macrophage colony-stimulating factor (I/T/DIN/GM-CSF) therapy.

PATIENTS AND METHODS

Patients eligible for this retrospective study were age < 30 years at diagnosis of HRNB and received ≥ 1 cycle of I/T/DIN/GM-CSF for relapsed or progressive disease. Patients with primary refractory disease who progressed through induction were excluded. Responses were evaluated using the International Neuroblastoma Response Criteria.

RESULTS

One hundred forty-six patients were included. Tumors were MYCN-amplified in 50 of 134 (37%). Seventy-one patients (49%) had an objective response to I/T/DIN/GM-CSF (objective response; 29% complete response, 14% partial response [PR], 5% minor response [MR], 21% stable disease [SD], and 30% progressive disease). Of patients with SD or better at first post-I/T/DIN/GM-CSF disease evaluation, 22% had an improved response per International Neuroblastoma Response Criteria on subsequent evaluation (13% of patients with initial SD, 33% with MR, and 41% with PR). Patients received a median of 4.5 (range, 1-31) cycles. The median progression-free survival (PFS) was 13.1 months, and the 1-year PFS and 2-year PFS were 50% and 28%, respectively. The median duration of response was 15.9 months; the median PFS off all anticancer therapy was 10.4 months after discontinuation of I/T/DIN/GM-CSF.

CONCLUSION

Approximately half of patients receiving I/T/DIN/GM-CSF for relapsed HRNB had objective responses. Patients with initial SD were unlikely to have an objective response, but > 1 of 3 patients with MR/PR on first evaluation ultimately had complete response. I/T/DIN/GM-CSF was associated with extended PFS in responders both during and after discontinuation of treatment. This study establishes a new comparator for response and survival in patients with relapsed HRNB.

Outcomes Following GD2-Directed Postconsolidation Therapy for Neuroblastoma After Cessation of Random Assignment on ANBL0032: A Report From the Children's Oncology Group

PURPOSE

Postconsolidation immunotherapy including dinutuximab, granulocyte-macrophage colony-stimulating factor, and interleukin-2 improved outcomes for patients with high-risk neuroblastoma enrolled on the randomized portion of Children's Oncology Group study ANBL0032. After random assignment ended, all patients were assigned to immunotherapy. Survival and toxicities were assessed.

PATIENTS AND METHODS

Patients with a pre-autologous stem cell transplant (ASCT) response (excluding bone marrow) of partial response or better were eligible. Demographics, stage, tumor biology, pre-ASCT response, and adverse events were summarized using descriptive statistics. Event-free survival (EFS) and overall survival (OS) from time of enrollment (up to day +200 from last ASCT) were evaluated.

RESULTS

From 2009 to 2015, 1,183 patients were treated. Five-year EFS and OS for the entire cohort were 61.1 ± 1.9% and 71.9 ± 1.7%, respectively. For patients ≥ 18 months old at diagnosis with International Neuroblastoma Staging System stage 4 disease (n = 662) 5-year EFS and OS were 57.0 ± 2.4% and 70.9 ± 2.2%, respectively. EFS was superior for patients with complete response/very good partial response pre-ASCT compared with those with PR (5-year EFS: 64.2 ± 2.2% v 55.4 ± 3.2%, P = .0133); however, OS was not significantly different. Allergic reactions, capillary leak, fever, and hypotension were more frequent during interleukin-2-containing cycles than granulocyte-macrophage colony-stimulating factor-containing cycles (P < .0001). EFS was superior in patients with higher peak dinutuximab levels during cycle 1 (P = .034) and those with a high affinity FCGR3A genotype (P = .0418). Human antichimeric antibody status did not correlate with survival.

CONCLUSION

Analysis of a cohort assigned to immunotherapy after cessation of random assignment on ANBL0032 confirmed previously described survival and toxicity outcomes. EFS was highest among patients with end-induction complete response/very good partial response. Among patients with available data, higher dinutuximab levels and FCGR3A genotype were associated with superior EFS. These may be predictive biomarkers for dinutuximab therapy.

Efficacy of post-induction therapy for high-risk neuroblastoma patients with end-induction residual disease

BACKGROUND

High-risk neuroblastoma patients with end-induction residual disease commonly receive post-induction therapy in an effort to increase survival by improving the response before autologous stem cell transplantation (ASCT). The authors conducted a multicenter, retrospective study to investigate the efficacy of this approach.

METHODS

Patients diagnosed between 2008 and 2018 without progressive disease with a partial response or worse at end-induction were stratified according to the post-induction treatment: 1) no additional therapy before ASCT (cohort 1), 2) post-induction "bridge" therapy before ASCT (cohort 2), and 3) post-induction therapy without ASCT (cohort 3). χ2 tests were used to compare patient characteristics. Three-year event-free survival (EFS) and overall survival (OS) were estimated by the Kaplan-Meier method and survival curves were compared by log-rank test.

RESULTS

The study cohort consisted of 201 patients: cohort 1 (n = 123), cohort 2 (n = 51), and cohort 3 (n = 27). Although the end-induction response was better for cohort 1 than cohorts 2 and 3, the outcomes for cohorts 1 and 2 were not significantly different (P = .77 for EFS and P = .85 for OS). Inferior outcomes were observed for cohort 3 (P < .001 for EFS and P = .06 for OS). Among patients with end-induction stable metastatic disease, 3-year EFS was significantly improved for cohort 2 versus cohort 1 (P = .04). Cohort 3 patients with a complete response at metastatic sites after post-induction therapy had significantly better 3-year EFS than those with residual metastatic disease (P = .01).

CONCLUSIONS

Prospective studies to confirm the benefits of bridge treatment and the prognostic significance of metastatic response observed in this study are warranted.

Molecular profiling identifies targeted therapy opportunities in pediatric solid cancer

To evaluate the clinical impact of molecular tumor profiling (MTP) with targeted sequencing panel tests, pediatric patients with extracranial solid tumors were enrolled in a prospective observational cohort study at 12 institutions. In the 345-patient analytical population, median age at diagnosis was 12 years (range 0-27.5); 298 patients (86%) had 1 or more alterations with potential for impact on care. Genomic alterations with diagnostic, prognostic or therapeutic significance were present in 61, 16 and 65% of patients, respectively. After return of the results, impact on care included 17 patients with a clarified diagnostic classification and 240 patients with an MTP result that could be used to select molecularly targeted therapy matched to identified alterations (MTT). Of the 29 patients who received MTT, 24% had an objective response or experienced durable clinical benefit; all but 1 of these patients received targeted therapy matched to a gene fusion. Of the diagnostic variants identified in 209 patients, 77% were gene fusions. MTP with targeted panel tests that includes fusion detection has a substantial clinical impact for young patients with solid tumors.

Novel ATXN1/ATXN1L::NUTM2A fusions identified in aggressive infant sarcomas with gene expression and methylation patterns similar to CIC-rearranged sarcoma

CIC-rearranged sarcomas are newly defined undifferentiated soft tissue tumors with CIC-associated fusions, and dismal prognosis. CIC fusions activate PEA3 family genes, ETV1/4/5, leading to tumorigenesis and progression. We report two high-grade CNS sarcomas of unclear histological diagnosis and one disseminated tumor of unknown origin with novel fusions and similar gene-expression/methylation patterns without CIC rearrangement. All three patients were infants with aggressive diseases, and two experienced rapid disease deterioration and death. Whole-transcriptome sequencing identified an ATXN1-NUTM2A fusion in the two CNS tumors and an ATXN1L-NUTM2A fusion in case 3. ETV1/4/5 and WT1 overexpression were observed in all three cases. Methylation analyses predicted CIC-rearranged sarcoma for all cases. Retrospective IHC staining on case 2 demonstrated ETV4 and WT1 overexpression. ATXN1 and ATXN1L interact with CIC forming a transcription repressor complex. We propose that ATXN1/ATXN1L-associated fusions disrupt their interaction with CIC and decrease the transcription repressor complex, leading to downstream PEA3 family gene overexpression. These three cases with novel ATXN1/ATXN1L-associated fusions and features of CIC-rearranged sarcomas may further expand the scope of "CIC-rearranged" sarcomas to include non-CIC rearrangements. Additional cases are needed to demonstrate if ATXN1/ATXN1L-NUTM2A fusions are associated with younger age and more aggressive diseases.

Abstract 5268: The spectrum of FGFR mutations in pediatric and young adult solid tumor

Fibroblast growth factor receptors (FGFRs) are a family of receptor tyrosine kinases expressed on the cell membrane that play crucial roles in cellular lineage commitment, differentiation, proliferation, and apoptosis. Deregulated FGFR signaling is observed in a subset of tumors across various histologies, making FGFRs ideal therapeutic targets. We sought to determine the genetic landscape of FGFR-family variations in a cohort of pediatric and young adult patients with solid tumors. The CHOP Comprehensive Solid Tumor Panel was performed on 1,420 patients. The panel covers 238 cancer genes and screens for single nucleotide variants (SNVs), indels, copy number alterations, and 117 fusion gene partners interrogating over 700 exons for known and novel fusions. Identified variants were categorized and reported according to the AMP/ASCO/CAP guidelines. Fifty-six patients (4.1%), including 47 children and 9 young adults, were found to carry at least one FGFR alteration in their tumors. CNS tumors accounted for most of the cases (51 total, 87.9%), with pilomyxoid astrocytoma/pilocytic astrocytoma and dysembryoplastic neuroepithelial tumor the most common (13 and 12 patients, respectively). Non-CNS solid tumors included rhabdomyosarcoma (4 patients), neuroblastoma/ganglioneuroblastoma (2), and follicular thyroid carcinoma (1). FGFR somatic alterations were found in 56 tumors including 41 SNVs and small indels, 6 internal tandem duplications (ITDs), and 15 fusions genes. The most common SNVs observed were hotspot mutations p.K656E and p.N546K of FGFR1. Sequence alterations in FGFR1 contained 35 SNVs and small indels, mostly gain of function mutations located in the kinase domain, and 6 kinase domain ITDs. One SNV was identified in FGFR2 in the immunoglobulin domain. Two SNVs were reported in FGFR3, both of which were in the fibroblast growth factor receptor family domain, and 3 SNVs were identified in FGFR4, all occurring at the p.V550 codon located on the kinase domain. Companion mutations in non-FGFR genes were detected in 27 tumors, predominantly involving RAS signaling pathway genes including NF1 (14 variants), PIK3CA (8), PTPN11 (6) and PIK3R1 (4). Among fusion variants, FGFR1-TACC1 fusions were found in 5 patients, mostly in pediatric patients. One FGFR3-TACC3 fusion was identified in one young adult patient. Seven pediatric patients tested positive for FGFR2 fusions; all with different 3’ partners. The detection of an FGFR alteration defined or changed the histologic diagnosis for 22 patients. Our results reveal that FGFR alterations account for 4.1% (56/1420) of the patients with solid tumors tested in our laboratory. The majority of the FGFR-positive tumors are low-grade CNS tumors. Further, the identification of FGFR alterations can significantly improve the tumor diagnosis and provide genomic evidence for potential targeted treatment with FGFR inhibitors.

Citation Format: Jinhua Wu, Jeffrey Schubert, Feng Xu, Ariel Long, Maha Patel, Netta Golenberg, Weixuan Fu, Kajia Cao, Jiani Chen, Elizabeth H. Denenberg, Elizabeth A. Fanning, Rochelle Bagatell, Theodore W. Laetsch, Adam Resnick, Mariarita Santi, Phillip Jay B. Storm, Minjie Luo, Lea F. Surrey, Yiming Zhong, Marilyn M. Li. The spectrum of FGFR mutations in pediatric and young adult solid tumor [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5268.

Racial, ethnic, and socioeconomic survival disparities among children with high-risk neuroblastoma treated on upfront Children’s Oncology Group clinical trials

10005

Background: Racial and socioeconomic disparities have not been comprehensively investigated in high-risk neuroblastoma (HR NBL). Prior Children’s Oncology Group (COG) investigations have demonstrated population-based disparities in late relapse rates among Black children, and trial-based disparities in relapse and survival among children living in poverty receiving post-consolidation immunotherapy. It is unknown whether these disparities persist in upfront trials for newly diagnosed patients. We leveraged COG data to investigate race, ethnicity, and socioeconomic disparities in a cohort of children with HR NBL treated on upfront clinical trials from 2007-2016. Methods: Retrospective cohort study of children enrolled on upfront COG HR NBL trials ANBL0532, ANBL09P1, and ANBL12P1. Race and ethnicity were the primary exposures categorized as: Black Non-Hispanic (BNH); Hispanic; Other Non-Hispanic (ONH); or White Non-Hispanic (WNH). Poverty was the secondary exposure, defined as household (public insurance only vs others), area (census-defined high-poverty ZIP code with >20% of population living below 100% Federal Poverty Level (FPL) vs <20% below 100% FPL), and rural (Census-defined rurality measures linked to ZIP code). Overall (OS) and event-free (EFS) survival from time of trial enrollment were plotted by Kaplan-Meier methods; associations with race/ethnicity and poverty were evaluated by log-rank tests. Results: Among 696 children, 16% were BNH, 11% Hispanic, 4% ONH, and 69% WNH. One-third (33%) of children were household poverty-exposed, 26% area poverty-exposed, and 15% rural-exposed. Tumor stage and biology did not differ by race/ethnicity or poverty measures. Five-year OS differed significantly by race/ethnicity (47% Hispanic vs. 50% ONH vs. 61% WNH vs. 62% BNH; p=0.047). Five-year OS was inferior among children exposed to household-poverty (53% vs. 63%; p=0.036) and neighborhood-poverty (54% vs. 62%; p=0.050) compared to unexposed children. There was no difference in OS by rurality. Similar directionality in 5-year EFS outcomes by race/ethnicity and poverty were observed without statistical significance. Conclusions: Race/ethnicity and poverty-exposure are associated with inferior OS outcomes among children with HR NBL despite uniform planned treatment on upfront COG trials. Investigation of mechanisms driving these disparities, including disparate early phase trial enrollment are ongoing to inform targeted health equity interventions to improve outcomes.

Progression-free survival and patterns of response in patients with high-risk neuroblastoma (HR-NB) treated with irinotecan/temozolomide/dinutuximab/granulocyte-macrophage colony-stimulating factor (I/T/DIN/GM-CSFS) chemoimmunotherapy

10025

Background: Encouraging responses to chemoimmunotherapy with I/T/DIN/GM-CSF have been observed in trials for patients (pts) with relapsed/refractory HR-NBL, but factors associated with response have not been identified and duration of response has not been assessed. We aimed to evaluate timing and duration of response among pts with relapsed HR-NBL treated with I/T/DIN/GM-CSF and identify factors associated with response. Methods: We performed a multicenter retrospective cohort study of pts treated with I/T/DIN/GM-CSF. Eligibility criteria included: diagnosis of relapsed HR-NBL prior to age 30; objective response [OR; complete, partial, or minor response (CR, PR, or MR) by International Neuroblastoma Response Criteria (INRC)] or stable disease (SD) after initial therapy; receipt of I/T/DIN/GM-CSF for relapse or progression outside a clinical trial from 1/1/15-6/1/20. Logistic regression was used to identify factors associated with OR. Kaplan Meier analysis was used to determine progression-free survival (PFS). Results: We enrolled 143 pts with a median age at diagnosis of 51 months. Tumors were MYCN amplified in 52 (36%) and ALK was wild type in 73/94 (78% of tumors in which ALK status was known). 79 (55%) had received prior anti-GD2 therapy. I/T/DIN/GM-CSF comprised first relapse therapy in 96 pts (67%), second relapse therapy in 23 (16%) and subsequent therapy in 24 (17%). 70 (49%) achieved OR following I/T/DIN/GM-CSF therapy [29% CR, 15% PR, 5% MR], 30 (21%) achieved SD and 43 (30%) progressed. Median cycles received was 5 (range 1-31). 121 patients (85%) had their best response upon first disease evaluation. Later disease evaluations showed improved INRC classification in 14% of pts with initial SD, 33% with MR, and 41% with PR. Median time to OR was 2 months (range 1-21). Of the 105 relapse/progression events after starting I/T/DIN/GM-CSF (73% of pts), 59 (56%) occurred during therapy. Of the 42 pts who achieved CR with I/T/DIN/GM-CSF, 5 (12%) relapsed during I/T/DIN/GM-CSF and 17 (40%) relapsed after discontinuation. I/T/DIN/GM-CSF was discontinued in 83 pts (58%) due to suboptimal response or PD, and in 19 (13%) for toxicity. Median PFS among objective responders was 15.5 months. Among those in CR, median PFS after discontinuation of I/T/DIN/GM-CSF was 11.8 months (range 0.7-70.6). Multivariable models did not identify clinical or biologic factors associated with OR. Conclusions: 49% of pts receiving I/T/DIN/GM-CSF for relapsed HR-NBL achieved OR. Among responders, median response duration was 15.5 months. Pts with SD on first disease evaluation were unlikely to achieve OR, but > 1/3 of pts with MR/PR on first evaluation ultimately achieved CR. No identifiable clinical or biologic factors were associated with OR.

Patterns of relapse after immunotherapy in patients with high-risk neuroblastoma

10043

Background: While the addition of anti-GD2 immunotherapy led to improvement in outcomes in patients on the Children’s Oncology Group (COG) ANBL0032 study, relapse remains a concern. Prior studies demonstrated the prognostic importance of time to first relapse, however, the effect of immunotherapy on timing and patterns of relapse in neuroblastoma (NBL) have yet to be evaluated. The purpose of this exploratory analysis was to describe the impact of immunotherapy on patterns of relapse in patients with high-risk NBL, including a descriptive comparison of sites of relapse based on post-consolidation treatment received [dinutuximab with cytokines and isotretinoin (DIN) vs isotretinoin alone (ISO)]. Methods: A retrospective, descriptive analysis of patients on ANBL0032 was performed, including patients randomized to DIN or ISO and those non-randomly assigned to DIN after ISO arm closure. Pt characteristics including age, stage, MYCN amplification status, tumor grade, mitosis-karyorrhexis index (MKI) and ploidy were summarized descriptively and relapse sites were tabulated. For DIN patients who subsequently relapsed, overall survival (OS) was calculated starting from the time of first relapse after enrollment on ANBL0032 (“post-relapse OS”). Kaplan-Meier OS curves were generated based on site of relapse. Results: The analytic cohort included 1,431 (DIN = 1,327; ISO = 104) patients. Among DIN patients, 492 relapsed, many in > 1 site. In the randomized cohort (n = 248), 122 relapsed (DIN = 68/144; ISO = 54/104). The frequencies (DIN; ISO) by site of relapse in the randomized cohort were: bone (53%; 54%), CNS (16%; 11%), lymph node (13%; 17%), abdominal (10%; 17%), paraspinal (6%; 2%), liver (3%; 4%), other soft tissue (22%; 7%). A higher proportion of ISO patients had marrow relapse (29.4% DIN; 48.2% ISO); however, the proportion of DIN patients with lung relapses appeared higher (9% vs 2%). Among all relapsed patients, the proportion with bone relapse did not appear to differ between treatment groups, regardless of MYCN status. Among patients with MYCN amplified disease, the proportion with marrow relapse did not appear to differ based on treatment [21/149 (14.1%) DIN; 3/20 (15.0%) ISO]; however, among patients with MYCN non-amplified disease, the proportion with marrow relapse appeared higher in the ISO group [16/23; 69.6%] vs the DIN group [52/193 (26.9%)]. Conclusions: In this exploratory analysis of patients on COG ANBL0032, the pattern for site of relapse appears to differ between patients treated with DIN vs ISO. While immunotherapy remains the treatment of choice in this population, the findings from this retrospective exploratory analysis warrant further investigation to decrease the risk for post-immunotherapy relapse. Clinical trial information: NCT00026312.

Predictors of differential outcomes according to response to induction chemotherapy in high-risk neuroblastoma

10032

Background: Response to induction chemotherapy has been shown to predict outcome in patients with high risk neuroblastoma, with those achieving a complete response (CR) having superior outcomes. Little is known about what factors impact survival within groups of patients with favorable and unfavorable end-induction response. We evaluated whether conventional prognostic factors remain prognostic in subsets of patients defined by response to induction. Methods: Patients from four COG high risk trials (A3973, ANBL02P1, ANBL0532, and ANBL12P1) were included. End-induction response was determined according to the 1993 International Neuroblastoma Response Criteria (INRC). Patients were categorized as having end-induction responses of CR, partial response (PR) or better, less than PR without progressive disease (PD), and PD. Univariate Cox models calculated OS hazard ratios for clinical and biological variables in subsets defined by response category. Results: 1,244 patients were included. Among all patients, age >5 years, INSS stage 4 disease, adrenal primary site and unfavorable histology by INPC were associated with inferior OS (see Table). Among patients who achieved a CR, stage 4 disease was the only factor that remained significantly associated with worse OS. Among those who achieved PR or better, age >5 years, stage 4 disease and unfavorable histology remained significantly associated with inferior OS. For those with less than PR but without PD, adrenal primary site, MYCN amplification and 1p LOH were significantly associated with inferior OS. For those with PD, MYCN amplification and 1p LOH were associated with worse OS, but older age was associated with better OS. Conclusions: Specific prognostic factors in neuroblastoma are associated with differential survival in groups defined by response to induction. Age, stage, and histology appear to be associated with OS for patients with more favorable response to induction, whereas MYCN and 1p LOH play a greater role in patients with unfavorable response to induction. These data can help to further define prognosis for patients with variable responses to induction. [Table: see text]

A pilot induction regimen incorporating dinutuximab and sargramostim for the treatment of newly diagnosed high-risk neuroblastoma: A report from the Children's Oncology Group

10003

Background: The addition of dinutuximab (DIN) in the post-consolidation setting led to improved event-free survival rates for patients with high-risk neuroblastoma. Chemoimmunotherapy including irinotecan, temozolomide, DIN and sargramostim (GM-CSF) in patients with recurrent or refractory neuroblastoma results in robust objective clinical responses. Evaluation of chemoimmunotherapy in the induction setting for patients with newly-diagnosed high-risk neuroblastoma (HR-NBL) warrants investigation. Methods: Children’s Oncology Group (COG) ANBL17P1 is a prospective, single arm, limited institution pilot study to assess the tolerability and feasibility of administering DIN (17.5mg/m2/dose, IV Days 2-5) and GM-CSF (250mcg/m2/dose, subcutaneous Days 6-count recovery) with COG Induction chemotherapy Cycles 3-5 for patients with newly-diagnosed high-risk neuroblastoma. The primary endpoint of tolerability included the number of toxic deaths and number of patients experiencing predefined unacceptable toxicities during Induction Cycles 3-5. Unacceptable toxicities included: hypotension requiring pressors > 24 hours, respiratory toxicity requiring ventilatory support > 24 hours, Grade 4 neuropathy that did not resolve prior to the next cycle, and failure to recover the ANC to > 750 mm3 by day 35. Feasibility was assessed as being able to receive > 75% of planned DIN doses administered during Induction Cycles 3-5. Revised International Neuroblastoma Response Criteria (INRC) were used to assess end of Induction (EOI) response. Results: Forty-two eligible and evaluable patients with newly-diagnosed high-risk neuroblastoma enrolled at 8 sites (22 [52.4%] males; median age 3.3 years at diagnosis) from January 14, 2019 to June 4, 2020. The most common DIN related Grade >3 toxicities observed during Induction Cycles 3-5 included fever (31.0%) and pain (9.5%). None of the patients experienced a toxic death or unacceptable toxicity during Induction Cycles 3-5. Thus, the regimen was deemed tolerable. Patients received 97.4% - 101.8% of the total DIN dose expected to be administered during Induction Cycles 3-5. Therefore, the regimen was deemed feasible. Thirty-eight of 42 patients completed the EOI evaluations, including 11 with complete response, 22 with partial response, 0 with minor response, 3 with stable disease and 2 with progressive disease. The overall EOI objective response rate (CR+PR+MR) was 86.8%. Conclusions: The administration of DIN and GM-CSF to COG Induction Cycles 3-5 for patients with newly-diagnosed high-risk neuroblastoma was tolerable and feasible. The objective response rate at EOI appears encouraging. This therapeutic regimen will be studied in a randomized phase 3 trial to further evaluate the efficacy of Induction phase chemoimmunotherapy for high-risk neuroblastoma. Clinical trial information: NCT03786783.

Impact of diagnostic and end-of-induction Curie scores in tandem autologous hematopoietic cell transplant for patients with high-risk neuroblastoma: A report from the Children’s Oncology Group

10027

Background: Diagnostic mIBG (meta-iodobenzylguanidine) scans are an integral component of response assessment in children with high-risk neuroblastoma. The role of end of induction (EOI) Curie Scores (CS) has been previously described in patients undergoing a single autologous hematopoietic cell transplant (AHCT) as consolidation therapy. We now examine the prognostic significance of CS in patients randomized to tandem or single AHCT on the Children’s Oncology Group (COG) trial ANBL0532. Methods: A retrospective analysis of mIBG scans obtained from patients enrolled in COG ANBL0532 (n = 652) was performed. Evaluable patients (n = 179) had mIBG-avid, International Neuroblastoma Staging System (INSS) stage 4 disease, did not progress during induction therapy, consented to consolidation randomization, and received either a single (n = 99) or tandem AHCT (n = 80). In addition, evaluable patients had paired mIBG scans at time of initial diagnosis and EOI. Optimal CS cut points maximized the outcome difference (≤ vs > CS cut-off) according to the Youden index. Log-rank tests compared EFS subgroups, with p < 0.05 considered statistically significant. 3-year EFS is presented ± standard error. EFS was estimated for relative reductions in CS of 50% and 75% from diagnosis to EOI. Results: For recipients of tandem AHCT, the optimal cut point at diagnosis was CS = 12, with superior EFS from study enrollment for patients with CS<12 (74.2±7.9%; n = 31) vs CS > 12 (59.2±7.1%; n = 49) (p = 0.002). At EOI, the optimal cut point was CS = 0, with superior EFS from EOI for patients with CS = 0 (72.9±6.4%; n = 48) vs CS > 0 (46.5±9.1%; n = 32) (p = 0.002). The cut point at diagnosis for recipients of single AHCT was CS = 21 (p = 0.04), while the EOI CS had an optimal cut point of 2, but without a significant difference in EFS (p = 0.29). Absolute CS at diagnosis and at EOI had a greater impact on outcome than the relative reduction in CS between diagnosis and EOI, for both single and tandem AHCT. Conclusions: In the setting of tandem transplantation for children with high-risk neuroblastoma, Curie scores at diagnosis and end-induction may identify a more favorable patient group. Patients treated with tandem AHCT who exhibited a CS<12 at diagnosis or CS = 0 at EOI had superior EFS compared to those with CS above these cut points. Similar to prior reports, a CS<2 was the optimal cut point for single transplant recipients. Clinical trial information: NCT00567567.

Guideline for Children With Cancer Receiving General Anesthesia for Procedures and Imaging

Children with cancer and those undergoing hematopoietic stem cell transplantation frequently require anesthesia for imaging as well as diagnostic and therapeutic procedures from diagnosis through follow-up. Due to their underlying disease and side effects of chemotherapy and radiation, they are at risk for complications during this time, yet no published guideline exists for preanesthesia preparation. A comprehensive literature review served as the basis for discussions among our multidisciplinary panel of oncologists, anesthesiologists, nurse practitioners, clinical pharmacists, pediatric psychologists, surgeons and child life specialists at the Children's Hospital of Philadelphia. Due to limited literature available, this panel created an expert consensus guideline addressing anesthesia preparation for this population.

Germline Sequencing Improves Tumor-Only Sequencing Interpretation in a Precision Genomic Study of Patients With Pediatric Solid Tumor

PURPOSE

Molecular tumor profiling is becoming a routine part of clinical cancer care, typically involving tumor-only panel testing without matched germline. We hypothesized that integrated germline sequencing could improve clinical interpretation and enhance the identification of germline variants with significant hereditary risks.

MATERIALS AND METHODS

Tumors from pediatric patients with high-risk, extracranial solid malignancies were sequenced with a targeted panel of cancer-associated genes. Later, germline DNA was analyzed for a subset of these genes. We performed a post hoc analysis to identify how an integrated analysis of tumor and germline data would improve clinical interpretation.

RESULTS

One hundred sixty participants with both tumor-only and germline sequencing reports were eligible for this analysis. Germline sequencing identified 38 pathogenic or likely pathogenic variants among 35 (22%) patients. Twenty-five (66%) of these were included in the tumor sequencing report. The remaining germline pathogenic or likely pathogenic variants were single-nucleotide variants filtered out of tumor-only analysis because of population frequency or copy-number variation masked by additional copy-number changes in the tumor. In tumor-only sequencing, 308 of 434 (71%) single-nucleotide variants reported were present in the germline, including 31% with suggested clinical utility. Finally, we provide further evidence that the variant allele fraction from tumor-only sequencing is insufficient to differentiate somatic from germline events.

CONCLUSION

A paired approach to analyzing tumor and germline sequencing data would be expected to improve the efficiency and accuracy of distinguishing somatic mutations and germline variants, thereby facilitating the process of variant curation and therapeutic interpretation for somatic reports, as well as the identification of variants associated with germline cancer predisposition.

Phase 1 study of sorafenib and irinotecan in pediatric patients with relapsed or refractory solid tumors

BACKGROUND

Sorafenib,an orally bioavailable, multitarget tyrosine kinase inhibitor, and irinotecan, a topoisomerase I inhibitor, have demonstrated activity in pediatric and adult malignancies. We evaluated the toxicity, pharmacokinetic (PK), and pharmacogenomic (PGX) profile of sorafenib with irinotecan in children with relapsed or refractory solid tumors and assessed the feasibility of incorporating patient-reported outcome (PRO) measures as an adjunct to traditional endpoints.

METHODS

Sorafenib, continuous oral twice daily dosing, was administered with irinotecan, orally, once daily days 1-5, repeated every 21 days (NCT01518413). Based on tolerability, escalation of sorafenib followed by escalation of irinotecan was planned. Three patients were initially enrolled at each dose level. Sorafenib and irinotecan PK analyses were performed during cycle 1. PRO measurements were collected during cycles 1 and 2.

RESULTS

Fifteen patients were evaluable. Two of three patients at dose level 2 experienced dose-limiting toxicity (DLT), grade 3 diarrhea, and grade 3 hyponatremia. Therefore, dose level 1 was expanded to 12 patients and two patients had DLT, grade 4 thrombocytopenia, grade 3 elevated lipase. Nine of 15 (60%) patients had a best response of stable disease with four patients receiving ≥6 cycles.

CONCLUSIONS

The recommended dose for pediatric patients was sorafenib 150 mg/m² /dose twice daily with irinotecan 70 mg/m² /dose daily × 5 days every 21 days. This oral outpatient regimen was well tolerated and resulted in prolonged disease stabilization. There were no significant alterations in the PK profile of either agent when administered in combination. Patients were willing and able to report their subjective experiences with this regimen.

A safety and feasibility trial of 131 I-MIBG in newly diagnosed high-risk neuroblastoma: A Children's Oncology Group study

INTRODUCTION

¹³¹ I-meta-iodobenzylguanidine (¹³¹ I-MIBG) is effective in relapsed neuroblastoma. The Children's Oncology Group (COG) conducted a pilot study (NCT01175356) to assess tolerability and feasibility of induction chemotherapy followed by ¹³¹ I^- MIBG therapy and myeloablative busulfan/melphalan (Bu/Mel) in patients with newly diagnosed high-risk neuroblastoma.

METHODS

Patients with MIBG-avid high-risk neuroblastoma were eligible. After the first two patients to receive protocol therapy developed severe sinusoidal obstruction syndrome (SOS), the trial was re-designed to include an ¹³¹ I-MIBG dose escalation (12, 15, and 18 mCi/kg), with a required 10-week gap before Bu/Mel administration. Patients who completed induction chemotherapy were evaluable for assessment of ¹³¹ I-MIBG feasibility; those who completed ¹³¹ I-MIBG therapy were evaluable for assessment of ¹³¹ I-MIBG + Bu/Mel feasibility.

RESULTS

Fifty-nine of 68 patients (86.8%) who completed induction chemotherapy received ¹³¹ I-MIBG. Thirty-seven of 45 patients (82.2%) evaluable for ¹³¹ I-MIBG + Bu/Mel received this combination. Among those who received ¹³¹ I-MIBG after revision of the study design, one patient per dose level developed severe SOS. Rates of moderate to severe SOS at 12, 15, and 18 mCi/kg were 33.3%, 23.5%, and 25.0%, respectively. There was one toxic death. The ¹³¹ I-MIBG and ¹³¹ I-MIBG+Bu/Mel feasibility rates at the 15 mCi/kg dose level designated for further study were 96.7% (95% CI: 83.3%-99.4%) and 81.0% (95% CI: 60.0%-92.3%).

CONCLUSION

This pilot trial demonstrated feasibility and tolerability of administering ¹³¹ I-MIBG followed by myeloablative therapy with Bu/Mel to newly diagnosed children with high-risk neuroblastoma in a cooperative group setting, laying the groundwork for a cooperative randomized trial (NCT03126916) testing the addition of ¹³¹ I-MIBG during induction therapy.

Revised Neuroblastoma Risk Classification System: A Report From the Children's Oncology Group

PURPOSE

Treatment planning for children with neuroblastoma requires accurate assessment of prognosis. The most recent Children's Oncology Group (COG) risk classification system used tumor stage as defined by the International Neuroblastoma Staging System. Here, we validate a revised classifier using the International Neuroblastoma Risk Group Staging System (INRGSS) and incorporate segmental chromosome aberrations (SCA) as an additional genomic biomarker.

METHODS

Newly diagnosed patients enrolled on the COG neuroblastoma biology study ANBL00B1 between 2007 and 2017 with known age, International Neuroblastoma Staging System, and INRGSS stage were identified (N = 4,832). Tumor MYCN status, ploidy, SCA status (1p and 11q), and International Neuroblastoma Pathology Classification histology were determined centrally. Survival analyses were performed for combinations of prognostic factors used in COG risk classification according to the prior version 1, and to validate a revised algorithm (version 2).

RESULTS

Most patients with locoregional tumors had excellent outcomes except for those with image-defined risk factors (INRGSS L2) with MYCN amplification (5-year event-free survival and overall survival: 76.3% ± 5.8% and 79.9% ± 5.5%, respectively) or patients age ≥ 18 months with L2 MYCN nonamplified tumors with unfavorable International Neuroblastoma Pathology Classification histology (72.7% ± 5.4% and 82.4% ± 4.6%), which includes the majority of L2 patients with SCA. For patients with stage M (metastatic) and MS (metastatic, special) disease, genomic biomarkers affected risk group assignment for those < 12 months (MYCN) or 12-18 months (MYCN, histology, ploidy, and SCA) of age. In a retrospective analysis of patient outcome, the 5-year event-free survival and overall survival using COG version 1 were low-risk: 89.4% ± 1.1% and 97.9% ± 0.5%; intermediate-risk: 86.1% ± 1.3% and 94.9% ± 0.8%; high-risk: 50.8% ± 1.4% and 61.9% ± 1.3%; and using COG version 2 were low-risk: 90.7% ± 1.1% and 97.9% ± 0.5%; intermediate-risk: 85.1% ± 1.4% and 95.8% ± 0.8%; high-risk: 51.2% ± 1.4% and 62.5% ± 1.3%, respectively.

CONCLUSION

A revised 2021 COG neuroblastoma risk classifier (version 2) that uses the INRGSS and incorporates SCAs has been adopted to prospectively define COG clinical trial eligibility and treatment assignment.

Clinical impact of molecular tumor profiling in pediatric, adolescent, and young adult patients with extra-cranial solid malignancies: An interim report from the GAIN/iCat2 study

10005

Background: Next generation sequencing (NGS) assays are now a standard part of clinical care for many adult solid cancers. The significance of molecular tumor profiling for the care of children with cancer is not well understood.We aimed to determine the clinical impact of identifying genomic alterations by NGS for young patients with relapsed, refractory, or high-risk extracranial solid tumors. Methods: We report on the first 389 participants in a prospective cohort study enrolling patients at 12 institutions with extracranial solid tumors diagnosed at age 30 years or less. Targeted DNA NGS was performed on one or more tumor samples from each patient. Selected patients also had tumors subjected to RNA sequencing. Test results were returned to the treating oncologist and follow-up treatment and response data were collected.Identified genomic alterations were classified according to evidence of impact on diagnosis, prognosis or response to targeted therapy matched to an identified alteration (matched targeted therapy, MTT) using established guidelines. Response to MTT was determined and reported as a response if either there was radiographic response according to RECIST or the duration of therapy was > 4 months. Results: Molecular tumor profiling (MTP) was successful in 345 (89%) patients (mean age 11 years at diagnosis; 65% with sarcoma). Two hundred and ninety-nine patients with MTP results (87%) had one or more alterations of clinical significance. Genomic alterations with diagnostic, prognostic or therapeutic significance were present in 208 (60%), 51 (15%) and 240 (70%) patients, respectively. Of the 240 patients with tumors harboring genomic alterations designated as having therapeutic impact, 23 (11%) had Tier 1 molecular findings. 205 patients were eligible to receive MTT based on having a molecular alteration with therapeutic significance and sufficient follow-up; 31 of these patients (15%) received MTT. Seven patients (23%) receiving MTT responded, 6 of these were kinase fusions. All of the responders received targeted therapy matched to a fusion and 78% of diagnostically significant alterations were fusions. Conclusions: Molecular tumor profiling has a significant impact on diagnosis and treatment recommendations for young patients with extracranial solid tumors. These results emphasize the importance of fusion detection for patients with sarcomas and rare tumors. Clinical trial information: NCT02520713.

Neuroblastoma

The survival of patients with high-risk neuroblastoma has improved significantly with the use of intensive multimodality treatment regimens, including chemotherapy, surgery, radiation therapy, myeloablative chemotherapy followed by stem cell rescue, and immunotherapy. This report summarizes the current treatment strategies used in the COG and SIOP for children with neuroblastoma. The improved global collaboration and the adoption of a uniform International Neuroblastoma Risk Group Staging System will help facilitate comparison of homogeneous pretreatment cohorts across clinical trials. Future research strategies regarding the indications for and dosages of radiation therapy to the primary and metastatic sites, and the integration of meta-iodobenzyl guanidine therapy into the multimodal treatment program, are discussed.

Myeloablative Busulfan/Melphalan Consolidation following Induction Chemotherapy for Patients with Newly Diagnosed High-Risk Neuroblastoma: Children's Oncology Group Trial ANBL12P1

Consolidation using high-dose chemotherapy with autologous stem cell transplantation (ASCT) is an important component of frontline therapy for children with high-risk neuroblastoma. The optimal preparative regimen is uncertain, although recent data support a role for busulfan/melphalan (BuMel). The Children's Oncology Group (COG) conducted a trial (ANBL12P1) to assess the tolerability and feasibility of BuMel ASCT following a COG induction. Patients with newly diagnosed high-risk neuroblastoma who did not progress during induction therapy and met organ function requirements received i.v. busulfan (every 24 hours for 4 doses based on age and weight) and melphalan (140 mg/m² for 1 dose), followed by ASCT. Busulfan doses were adjusted to achieve to an average daily area under the curve (AUC) <5500 µM × minute. The primary endpoint was the occurrence of severe sinusoidal obstruction syndrome (SOS) or grade ≥4 pulmonary complications within the first 28 days after completion of consolidation therapy. A total of 146 eligible patients were enrolled, of whom 101 underwent BuMel ASCT. The overall incidence of protocol-defined unacceptable toxicity during consolidation was 6.9% (7 of 101). Six patients (5.9%) developed SOS, with 4 (4%) meeting the criteria for severe SOS. An additional 3 patients (3%) experienced grade ≥4 pulmonary complications during consolidation. The median busulfan AUC was 4558 µM × min (range, 3462 to 5189 µM × minute) for patients with SOS and 3512 µM × min (2360 to 5455 µM × minute) (P = .0142). No patients died during consolidation. From the time of study enrollment, the mean 3-year event-free survival for all 146 eligible patients was 55.6 ± 4.2%, and the mean 3-year overall survival was 74.5 ± 3.7%. The BuMel myeloablative regimen following COG induction was well tolerated, with acceptable pulmonary and hepatic toxicity.

Long-Term Follow-up of a Phase III Study of ch14.18 (Dinutuximab) + Cytokine Immunotherapy in Children with High-Risk Neuroblastoma: COG Study ANBL0032

PURPOSE

Previously our randomized phase III trial demonstrated that immunotherapy including dinutuximab, a chimeric anti-GD2 mAb, GM-CSF, and IL2 improved survival for children with high-risk neuroblastoma that had responded to induction and consolidation therapy. These results served as the basis for FDA approval of dinutuximab. We now present long-term follow-up results and evaluation of predictive biomarkers.

PATIENTS AND METHODS

Patients recieved six cycles of isotretinoin with or without five cycles of immunotherapy which consists of dinutuximab with GM-CSF alternating with IL2. Accrual was discontinued early due to meeting the protocol-defined stopping rule for efficacy, as assessed by 2-year event-free survival (EFS). Plasma levels of dinutuximab, soluble IL2 receptor (sIL2R), and human anti-chimeric antibody (HACA) were assessed by ELISA. Fcγ receptor 2A and 3A genotypes were determined by PCR and direct sequencing.

RESULTS

For 226 eligible randomized patients, 5-year EFS was 56.6 ± 4.7% for patients randomized to immunotherapy (n = 114) versus 46.1 ± 5.1% for those randomized to isotretinoin only (n = 112; P = 0.042). Five-year overall survival (OS) was 73.2 ± 4.2% versus 56.6 ± 5.1% for immunotherapy and isotretinoin only patients, respectively (P = 0.045). Thirteen of 122 patients receiving dinutuximab developed HACA. Plasma levels of dinutuximab, HACA, and sIL2R did not correlate with EFS/OS, or clinically significant toxicity. Fcγ receptor 2A and 3A genotypes did not correlate with EFS/OS.

CONCLUSIONS

Immunotherapy with dinutuximab improved outcome for patients with high-risk neuroblastoma. Early stoppage for efficacy resulted in a smaller sample size than originally planned, yet clinically significant long-term differences in survival were observed.

Poverty and Targeted Immunotherapy: Survival in Children's Oncology Group Clinical Trials for High-Risk Neuroblastoma

BACKGROUND

Whether social determinants of health are associated with survival in the context of pediatric oncology-targeted immunotherapy trials is not known. We examined the association between poverty and event-free survival (EFS) and overall survival (OS) for children with high-risk neuroblastoma treated in targeted immunotherapy trials.

METHODS

We conducted a retrospective cohort study of 371 children with high-risk neuroblastoma treated with GD2-targeted immunotherapy in the Children's Oncology Group trial ANBL0032 or ANBL0931 at a Pediatric Health Information System center from 2005 to 2014. Neighborhood poverty exposure was characterized a priori as living in a zip code with a median household income within the lowest quartile for the cohort. Household poverty exposure was characterized a priori as sole coverage by public insurance. Post hoc analyses examined the joint effect of neighborhood and household poverty using a common reference. All statistical tests were 2-sided.

RESULTS

In multivariable Cox regressions adjusted for disease and treatment factors, household poverty-exposed children experienced statistically significantly inferior EFS (hazard ratio [HR] = 1.90, 95% confidence interval [CI] = 1.28 to 2.82, P = .001) and OS (HR = 2.79, 95% CI = 1.63 to 4.79, P < .001) compared with unexposed children. Neighborhood poverty was not independently associated with EFS or OS. In post hoc analyses exploring the joint effect of neighborhood and household poverty, children with dual-poverty exposure (neighborhood poverty and household poverty) experienced statistically significantly inferior EFS (HR = 2.21, 95% CI = 1.48 to 3.30, P < .001) and OS (HR = 3.70, 95% CI = 2.08 to 6.59, P < .001) compared with the unexposed group.

CONCLUSIONS

Poverty is independently associated with increased risk of relapse and death among neuroblastoma patients treated with targeted immunotherapy. Incorporation of social and environmental factors in future trials as health-care delivery intervention targets may increase the benefit of targeted therapies.

Racial and Ethnic Differences in Communication and Care for Children With Advanced Cancer

CONTEXT

Racial and ethnic disparities in end-of-life care are well documented among adults with advanced cancer.

OBJECTIVES

To examine the extent to which communication and care differ by race and ethnicity among children with advanced cancer.

METHODS

We conducted a prospective cohort study at nine pediatric cancer centers enrolling 95 parents (42% racial/ethnic minorities) of children with poor prognosis cancer (relapsed/refractory high-risk neuroblastoma). Parents were surveyed about whether prognosis was discussed; likelihood of cure; intent of current treatment; and primary goal of care. Medical records were used to identify high-intensity medical care since the most recent recurrence. Logistic regression evaluated differences between white non-Hispanic and minority (black, Hispanic, and Asian/other race) parents.

RESULTS

About 26% of parents recognized the child's low likelihood of cure. Minority parents were less likely to recognize the poor prognosis (odds ratio [OR] = 0.19; 95% CI = 0.06-0.63; P = 0.006) and the fact that current treatment was unlikely to offer cure (OR = 0.07; 95% CI = 0.02-0.27; P < 0.0001). Children of minority parents were more likely to experience high-intensity medical care (OR = 3.01; 95% CI = 1.29-7.02; P = 0.01). After adjustment for understanding of prognosis, race/ethnicity was no longer associated with high-intensity medical care (adjusted odds ratio = 2.14; 95% CI = 0.84-5.46; P = 0.11), although power to detect an association was limited.

CONCLUSION

Parental understanding of prognosis is limited across racial and ethnic groups; racial and ethnic minorities are disproportionately affected. Perhaps as a result, minority children experience higher rates of high-intensity medical care. Work to improve prognostic understanding should include focused work to meet needs of minority populations.

Trends in conditional survival and predictors of late death in neuroblastoma

PURPOSE

Significant advances in the treatment of neuroblastoma have been made in the past several decades. There are scant data examining how these improvements have changed over time and differentially affected conditional survival among high-risk and non-high-risk patient groups.

METHODS

We conducted a retrospective cohort study using the Surveillance, Epidemiology, and End Results database. We analyzed clinical characteristics and survival outcomes for 4717 neuroblastoma patients. Kaplan-Meier methods were used to estimate overall survival (OS) and conditional overall survival (COS) with estimates compared between groups using log-rank tests.

RESULTS

Five-year OS was 41.46% (95% CI 38.77-44.13) for the high-risk group and 91.13% (95% CI 89.49-92.53) for the non-high-risk group. Both groups saw significant improvements in OS by decade (P < .001). Five-year COS among 1-year survivors was 52.69% (CI 49.54-55.73) for the high-risk group and 96.75% (95% CI 95.57-97.62) for the non-high-risk group. One-year survivors in the high-risk group showed a statistically significant improvement in COS over time. No difference in COS was observed among 5-year high-risk survivors. In the high-risk and non-high-risk groups, 82% and 32% of late deaths were attributable to cancer, respectively. Statistically significant adverse prognostic factors for late death were age ≥ 1 year at diagnosis, metastatic disease, and nonthoracic primary site (P = .001).

CONCLUSIONS

Improvements in COS over time have largely benefited high-risk patients, though they are still at higher risk for late death due to cancer when compared to non-high-risk patients. Age, stage, and primary site, but not treatment decade, influence outcomes among 5-year survivors.

Abstract A06: The added value of examining germline variants in a precision cancer therapy study

Introduction: Tumor profiling is becoming a more routine part of clinical care. Many academic centers and commercial entities offer tumor sequencing of cancer-related genes without matched germline profiling. We hypothesize that tumor-only sequencing may limit full clinical interpretation and have decreased sensitivity to identify significant germline variants.

Methods: The Genomic Assessment Improves Novel Therapy (GAIN) Consortium is a clinical cancer genomics study for patients with high-risk solid malignancies. Patients in this study were selected for subanalysis if panel sequencing of 447 genes was performed on a tumor and interpreted by an expert panel prior to the availability of matched germline sequencing. Interpretation of tumor sequencing included both therapeutic recommendations and a curation of cancer-related variants of potential clinical significance if present in the germline. Germline sequencing was separately performed targeting 147 genes (a subset of the somatic panel) and analyzed with a germline-specific pipeline to identify and filter variants. We examined clinical recommendations in the somatic reports that were based on single-nucleotide variants identified from the 147 overlapping genes. We compared these interpretations with results from the matched germline data.

Results: We identified 159 participants with somatic and germline sequencing reports meeting the eligibility criteria. Germline sequencing identified 38 pathogenic or likely pathogenic (P/LP) germline variants in 35 of 159 patients (22%). Of those 35 patients, 17 (49%) had a P/LP variant in an autosomal dominant cancer predisposition gene, 19 (54%) in an autosomal recessive gene, and 1 (2.9%) in a noncancer gene. Of the 38 total variants, 21 (55%) were identified by the analytic pipeline used for somatic sequencing and noted as potential germline variants in the somatic reports. Forty treatment recommendations were made from the somatic data within the overlapping genes. Ten (25%) treatment recommendations were based on variants that were later determined to be germline. These included variants in TP53, SDHA, SMARCA4, TSC2, FAM175A, CHEK2, and AKT1, many of which were noted in the somatic reports to be variants of uncertain significance or possibly germline.

Conclusions: In this study, we found that clinically actionable germline variants were under-reported when relying on analytical pipelines and clinical interpretations developed for the analysis of tumor samples. In the absence of germline sequencing, we also found that cancer treatment recommendations can be made based on mutations identified from tumor sequencing that are germline variants. In many cases, these recommendations remain appropriate (e.g., PARP inhibitors for BRCA1/2) while in other cases germline data facilitated a more nuanced interpretation of actionability. These findings support the use of germline genetic testing and paired tumor-germline analysis in precision cancer medicine studies.

Citation Format: Jaclyn Schienda, Catherine M. Clinton, Laura B. Corson, Alma Imamovic-Tuco, Navin Pinto, Luke Maese, Theodore W. Laetsch, AeRang Kim, Susan I. Vear, Margaret E. Macy, Mark A. Applebaum, Rochelle Bagatell, Amit J. Sabnis, Daniel A. Weiser, Julia L. Glade-Bender, Samuel L. Volchenboum, Wenjun Kang, Danielle Manning, Jonathan Nowak, Joshua Schiffman, Neal I. Lindeman, Alanna J. Church, Katherine A. Janeway, Brian D. Crompton, Junne Kamihara. The added value of examining germline variants in a precision cancer therapy study [abstract]. In: Proceedings of the AACR Special Conference on the Advances in Pediatric Cancer Research; 2019 Sep 17-20; Montreal, QC, Canada. Philadelphia (PA): AACR; Cancer Res 2020;80(14 Suppl):Abstract nr A06.

Abstract B13: Leveraging cloud-based computational resources for gene fusion discovery with potential clinical implications for pediatric solid tumor patients

Introduction: Gene fusions are important oncogenic drivers with significant clinical impact in some cancer types. This is particularly true in pediatric cancers that often have low mutational burden and lack other diagnostic markers and therapeutic targets. Many gene fusions are rare or private to the individual patient and can be difficult to detect with methods optimized for common fusions. Unbiased sequencing methods and expansive computational resources are needed for expanding our ability to characterize fusions. Building a comprehensive catalog of oncogenic gene fusions will improve our understanding of their diversity and fully harness their potential for clinical impact.

Methods: Patients are eligible for the GAIN/iCat2 study if they have been diagnosed with high-risk or recurrent/refractory extracranial solid tumor at age 30 or less and have a sample available for sequencing. Enrolled patients with an unclear diagnosis after standard clinical testing are nominated for transcriptome sequencing by the study investigators. We developed a computational pipeline in Google Cloud for gene fusion discovery utilizing paired end Illumina RNA-Seq data, multiple fusion callers, and a custom algorithm for integrative data analysis. The multicaller fusion detection approach enables us to address the high false-positive rate typical for gene fusion calling in transcriptomic data while improving the sensitivity to detect the more challenging fusions. After filtering, the fusions are annotated using the databases of known fusions and cancer genes. The predicted fusion transcripts are inspected visually, and the fusions are selected based on relevance to diagnostic classification or therapy to be validated by an orthogonal method.

Results: 41 tumor samples were sequenced and analyzed for gene fusions. A total of 203 candidate fusions were detected by two or more fusion callers. Based on functional annotations and potential impact on diagnosis or therapeutic approaches, 12 fusion transcripts of interest were identified, 10 of which were validated by either pre-enrollment testing or an orthogonal method. Of 16 mesenchymal cases, 6 validated fusions had diagnostic relevance and 3 validated fusions had therapeutic implications (ERC1-BRAF, RBPMS-NTRK2, and VCAN-IL23R). Two patients responded to matched targeted therapy. In one case, diagnostic classification was revised.

Conclusions: Whole-transcriptome sequencing in this selected patient population identified some fusion transcripts with clinical relevance. Determining the biologic significance of previously unreported fusions will require orthogonal sequencing such as whole genome, functional studies, and analysis of larger patient populations. Improved accuracy and scalability of methods for large-scale gene fusion analysis in the growing public datasets are likely to expand the landscape of gene fusions in cancer.

Citation Format: Alma Imamovic, Alanna J. Church, Laura B. Corson, Deirdre Reidy, Navin Pinto, Luke Maese, Theodore W. Laetsch, AeRang Kim, Susan I. Vear, Margaret E. Macy, Mark A. Applebaum, Rochelle Bagatell, Amit J. Sabnis, Daniel A. Weiser, Julia L. Glade-Bender, Gianna R. Strand, Lobin A. Lee, R. Seth Pinches, Catherine M. Clinton, Brian D. Crompton, Neal I. Lindeman, Steven G. DuBois, Katherine A. Janeway, Eliezer M. Van Allen. Leveraging cloud-based computational resources for gene fusion discovery with potential clinical implications for pediatric solid tumor patients [abstract]. In: Proceedings of the AACR Special Conference on the Advances in Pediatric Cancer Research; 2019 Sep 17-20; Montreal, QC, Canada. Philadelphia (PA): AACR; Cancer Res 2020;80(14 Suppl):Abstract nr B13.

Abstract A59: Sequencing identifies diagnostically relevant alterations in pediatric solid tumor patients

Introduction: Molecular techniques have been incorporated into the diagnostic algorithms for many specific tumors, but the diagnostic role of next-generation sequencing has not been described at a population level. We report diagnostically relevant alterations identified by large-scale sequencing in a prospective cohort of pediatric solid tumors.

Methods and Objectives: Patients are eligible for the GAIN / iCat2 study if they have a high-risk, recurrent, or refractory extracranial solid tumor diagnosed at age 30 or less and have an adequate sample for sequencing available. After informed consent, tumor was sequenced using a next-generation sequencing assay that evaluates 447 genes and includes data about sequence variants, copy number alterations, and, in selected genes, translocations. Some cases received additional sequencing via RNASeq or targeted RNA sequencing for further evaluation of fusions. Diagnostic relevance was determined according to AMP/ASCO/CAP standards and guidelines for the reporting of sequence variants in cancer.

Results: 349 patients were enrolled as of December 31, 2018, and had tumor tissue successfully sequenced. These patients represent 60 unique diagnoses according to the WHO ICD-O classification. The most common single diagnoses were osteosarcoma (n=64), Ewing sarcoma (n=44), and alveolar rhabdomyosarcoma (n=32). For 349 patients, 184 (53%) had one or more genetic alterations that were diagnostically relevant, of which 159 (86%) were structural variants, 16 (8%) were sequence variants, and 9 (5%) were copy number variations. Alterations of high diagnostic relevance include CIC-DUX4 fusions in sarcoma (n=8), TP53 intron 1 rearrangements in osteosarcoma (n=26), DICER1 sequence variants in various tumors (n=7), and BCOR internal tandem duplications in clear-cell sarcoma of kidney and primitive myxoid mesenchymal tumor of infancy (n=3).

Conclusions: Diagnostically relevant alterations were identified in over half of pediatric solid tumor patients evaluated. Gene fusions are particularly prevalent. These results support a role for sequencing that includes robust fusion assessment to inform diagnosis in patients with pediatric solid tumors.

Citation Format: Alanna J. Church, Laura B. Corson, Alma Imamovic-Tuco, Gianna R. Strand, Dierdre Reidy, Duong Doan, Robert S. Pinches, Mark A. Applebaum, Rochelle Bagatell, Brian D. Crompton, Steven G. DuBois, Julia L. Glade Bender, Theodore W. Laetsch, Lobin A. Lee, Neal I. Lindeman, Marian H. Harris, Margaret E. Macy, Luke Maese, Navin Pinto, Amit J. Sabnis, Eliezer M. Van Allen, Susan I. Vear, Daniel A. Weiser, Catherine M. Clinton, Katherine A. Janeway. Sequencing identifies diagnostically relevant alterations in pediatric solid tumor patients [abstract]. In: Proceedings of the AACR Special Conference on the Advances in Pediatric Cancer Research; 2019 Sep 17-20; Montreal, QC, Canada. Philadelphia (PA): AACR; Cancer Res 2020;80(14 Suppl):Abstract nr A59.

Association of heterogeneous MYCN amplification with clinical features, biological characteristics and outcomes in neuroblastoma: A report from the Children's Oncology Group

PURPOSE

MYCN amplification (MNA) is associated with poor outcomes in neuroblastoma. Less is known about heterogeneous MNA within a tumour. We compared clinical characteristics, biologic features and clinical outcomes of patients with heterogeneous MNA to patients with either homogeneous MNA or MYCN wild-type tumours.

PATIENTS AND METHODS

In this retrospective cohort study, we categorized patients as having tumours with MYCN wild-type, homogeneous MNA (>20% amplified tumour cells) or heterogeneous MNA (≤20% amplified tumour cells). We used chi-squared or Fisher's exact tests to compare features between groups. We used log-rank tests and Cox models to compare event-free survival (EFS) and overall survival (OS) between groups.

RESULTS

MYCN status and heterogeneity status (if amplified) could be ascertained in diagnostic tumour samples from 5975 patients, including 57 (1%) with heterogeneous MNA, 981 (16.4%) with homogeneous MNA, and 4937 (82.6%) with MYCN wild-type tumours. Multiple clinical and biological features differed between patients with heterogeneous vs. homogeneous MNA, including enrichment for thoracic primary sites and paucity of 1p loss of heterozygosity with heterogeneous MNA (p < 0.0001). Importantly, EFS and OS were not significantly different between patients with heterogeneous vs. homogeneous MNA. Further, EFS and OS for patients with heterogeneous MNA were significantly inferior to patients with wild-type MYCN.

CONCLUSION

Although neuroblastomas with heterogeneous MNA demonstrate significantly different biological and clinical patterns compared with homogeneous MNA, prognosis is similar between the two groups. These results support current practice that treats patients with heterogeneous MNA similarly to patients with homogeneous MNA.

Outcomes among pediatric patients with cancer who are treated on trial versus off trial: A matched cohort study

BACKGROUND

Approximately 50% of children with cancer in the United States who are aged <15 years receive primary treatment on a therapeutic clinical trial. To the authors' knowledge, it remains unknown whether trial enrollment has a clinical benefit compared with the best alternative standard therapy and/or off trial (ie, clinical trial effect). The authors conducted a retrospective matched cohort study to compare the morbidity and mortality of pediatric patients with cancer who are treated on a phase 3 clinical trial compared with those receiving standard therapy and/or off trial.

METHODS

Subjects were aged birth to 19 years; were diagnosed between 2000 and 2010 with acute lymphocytic leukemia (ALL), acute myeloid leukemia (AML), rhabdomyosarcoma, or neuroblastoma; and had received initial treatment at the Children's Hospital of Philadelphia. On-trial and off-trial subjects were matched based on age, race, ethnicity, a diagnosis of Down syndrome (for patients with ALL or AML), prognostic risk level, date of diagnosis, and tumor type.

RESULTS

A total of 428 participants were matched in 214 pairs (152 pairs for ALL, 24 pairs for AML, 32 pairs for rhabdomyosarcoma, and 6 pairs for neuroblastoma). The 5-year survival rate did not differ between those treated on trial versus those treated with standard therapy and/or off trial (86.9% vs 82.2%; P = .093). On-trial patients had a 32% lower odds of having worse (higher) mortality-morbidity composite scores, although this did not reach statistical significance (odds ratio, 0.68; 95% confidence interval, 0.45-1.03 [P = .070]).

CONCLUSIONS

There was no statistically significant difference in outcomes noted between those patients treated on trial and those treated with standard therapy and/or off trial. However, in partial support of the clinical trial effect, the results of the current study indicate a trend toward more favorable outcomes in children treated on trial compared with those treated with standard therapy and/or off trial. These findings can support decision making regarding enrollment in pediatric phase 3 clinical trials.

Outcome in patients with refractory high-risk neuroblastoma

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Background: Outcome for high-risk neuroblastoma (HRNBL) patients (pts) with refractory disease at end of induction (EOI) is poor. The impact of therapies such as I-131-MIBG or irinotecan/temozolomide/dinutuximab (I/T/DIN) prior to autologous stem cell transplant (ASCT) on outcome is unknown. Methods: A multi-center, retrospective study of HRNBL pts diagnosed between 2008-2018 with refractory disease at EOI was conducted. Demographics, tumor biology, treatment response, and outcomes were abstracted. 3-year (yr) EFS and OS from time of diagnosis were estimated by the Kaplan-Meier method. Results: 3-yr EFS and OS were 54% and 79% for the 136 pts analyzed. 91 pts received no additional therapy prior to ASCT (Cohort 1); 32 pts received post-induction therapy prior to ASCT (Cohort 2); and 13 pts did not undergo ASCT (Cohort 3). The prevalence of metastatic disease in Cohort 1, 2, and 3 was 65%, 97%, and 85%. 3-yr EFS and OS were not statistically different between Cohort 1 (3-yr EFS and OS; 62% and 81%) and Cohort 2 [3-yr EFS and OS; 49% (p = 0.48) and 82% (p = 0.19)]. Outcome for Cohort 3 pts was significantly worse than Cohort 1 [3-yr EFS: 15% vs. 62% (p < .001); and 3-yr OS: 48% vs. 81% (p = 0.003)] and Cohort 2 [3-yr EFS: 15% vs. 49% (p < .001); and 3-yr OS 48% vs. 82% (p = 0.035)]. For Cohort 2 pts with metastatic disease, post-induction therapy included I/T/DIN (n = 12), MIBG (n = 16), MIBG plus I/T/DIN (n = 1), and other (n = 2). Metastatic disease response was observed in 10/12 (83%) pts who received I/T/DIN and 9/16 (56%) who received MIBG. MIBG plus I/T/DIN (n = 1) or MIBG with chemotherapy (n = 1) also induced response. Among the 21 pts with metastatic disease response, 3-yr EFS and OS were 69% and 94%; significantly better than Cohort 2 patients who did not respond to post-induction therapy [3-yr EFS and OS: 11% (p = 0.016) and 66% (p = 0.2)]. 6 Cohort 2 pts achieved a complete response (CR) in metastatic sites following I/T/DIN (n = 5) or MIBG (n = 1), and all are alive without relapse with median follow-up of 3.4 years (range 2.7-8.1). The single Cohort 3 patient who achieved a metastatic CR with I/T/DIN and did not undergo ASCT remains disease-free 2.4 years from diagnosis. Conclusions: Patient characteristics differed in the 3 Cohorts, reflecting the influence of refractory disease on treatment decisions. For Cohort 2 pts, outcome was better for those with metastatic disease at EOI who responded to post-induction therapy compared to those who did not. Pts who achieved a metastatic CR of refractory disease had excellent survival. Prospective studies testing the efficacy of I/T/DIN in pts with refractory metastatic disease at EOI are warranted.

Clinical significance of serial tumor next generation sequencing (NGS) in 155 pediatric cancer patients

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Background: Molecular profiling using NGS technology is critical for tumor diagnosis, risk stratification, and treatment selection. There are limited data in childhood cancers regarding evolution of genomic changes under the selective pressure of chemoradiotherapy. Here we report on serial testing of hematologic and solid pediatric tumor specimens across the spectrum of diagnosis, during treatment and disease relapse. Methods: Since 2016, 2,144 somatic NGS assays from 1,727 unique cancer patients were performed using the Comprehensive Hematological Malignancy Panel (CHMP) or the Comprehensive Solid Tumor Panel (CSTP). Serial tumor analysis was performed on 155 patients. All tumors were profiled for SNVs/indels, copy number alterations (CNAs), and fusions. The clinical impact on diagnosis, prognosis, and therapy was assessed. Results: 85 and 70 patients were tested with CHMP and CSTP, respectively. 86.5% (134/155) of patients underwent 1 subsequent genetic testing, while 13.5% (21/155) were serially tested for 3 - 6 times. Relapsed or therapy-refractory tumor was the most common indication for repeat CHMP and CSTP analysis of tumor genomics (64.5%, 100/155), primarily to survey for new targetable cancer driver mutations. The second most common reason for serial testing with CHMP was to monitor clonal evolution for patients with bone marrow failure syndromes and/or myelodysplastic syndromes, which resulted in a new cancer diagnosis in 14.6% (6/41) patients. For CSTP, the second most common reason for serial testing was to test a different part of the same tumor for tumors with histologic and/or radiographic heterogeneity (27.1%, 19/70). Of all patients with serial testing, 70 had at least one clinically significant new SNV/indel, 44 had distinct CNAs, and 4 had new clinically actionable fusions. Overall, clinically significant new results were detected in 81 (52.3%) patients, including 53 patients with new clonal changes indicating disease evolution, 31 of diagnostic significance, 9 of prognostic significance, and 8 suggesting new treatment options. Conclusions: Taken together, these data highlight the clinical importance of serial testing of pediatric tumors for potential biomarkers that may impact patients’ care at various time points across the spectrum of their diseases.

Trends in conditional survival and predictors of late death in neuroblastoma

10533

Background: Significant advances in the treatment of neuroblastoma have been made in the past several decades. There are scant data examining how these improvements have changed over time and differentially affected conditional survival among high- and non-high-risk patient groups. Methods: We conducted a retrospective cohort study using the Surveillance, Epidemiology, and End Results Database. We analyzed clinical characteristics and survival outcomes for 4717 neuroblastoma patients. Kaplan-Meier methods were used to estimate overall survival (OS) and conditional overall survival (COS) conditioned on having survived 1, 2, or 5 years from diagnosis, with estimates compared between groups using log-rank tests. Results: Five-year OS was 41.46% (95% CI 38.77-44.13) for the high-risk group and 91.13% (95% CI 89.49-92.53) for the non-high-risk group. Both groups saw significant improvements in OS by decade (p<0.001). Five-year COS among 1-year survivors was 52.69% (95% CI 38.77-44.13) for the high-risk group and 96.75% (95% CI 95.57-97.62) for the non-high-risk group. One-year survivors in the high-risk group showed a statistically significant improvement in COS over time. No difference in COS was observed among 5-year high-risk survivors. There were no statistically significant changes in COS over time for 1- and 5-year survivors in the non-high-risk group. In the high-risk and non-high-risk groups, 82% and 32% of late deaths (>5 years from diagnosis) were attributable to cancer, respectively. Statistically significant adverse prognostic factors for late death were age >1 year at diagnosis, metastatic disease, and non-thoracic primary site (p=0.001). Conclusions: Improvements in COS over time have largely benefited high-risk patients, though they are still at higher risk for late death due to cancer when compared to non-high-risk patients. Age, stage, and primary site, but not treatment decade, influence outcomes among 5-year survivors. [Table: see text]

Outcomes and toxicities in patients (pts) non-randomly assigned to immunotherapy Children’s Oncology Group (COG) ANBL0032

10523

Background: Immunotherapy with the anti-GD2 antibody dinutuximab plus sargramostim (GM-CSF), aldesleukin (IL-2) and isotretinoin following consolidation therapy improved outcome for high-risk neuroblastoma (HRNBL) pts enrolled on COG ANBL0032. Randomization was halted in 2009; subsequent pts were non-randomly assigned to immunotherapy. Toxicities and survival were evaluated. Methods: HRNBL pts < 31 years old with a pre-autologous stem cell transplant (ASCT) response of ≥ partial response (PR) were eligible. Demographics, INSS stage, tumor biology, 1993 INRC pre-ASCT response and toxicities were summarized using descriptive statistics. Five-year (yr) EFS and OS from time of study enrollment were estimated. Results: From 2009-2015, 1,183 pts were non-randomly assigned to immunotherapy. 96.7% (n = 1,144) were ≥18 months old and 83.1% (n = 765/921) had stage 4 disease. 45.1% (n = 363/805) of tumors with known biology were MYCN amplified, 94.5% (n = 749/793) had unfavorable histology, and 54.9% (n = 397/723) were diploid. Pre-ASCT, 352 (29.8%) pts had complete response (CR), 418 (35.3%) had very good partial response (VGPR), and 413 (34.9%) had PR. 1,042 (88.1%) pts underwent a single and 141 (11.9%) underwent tandem ASCT. For the entire cohort, 5-yr EFS was 61.1±1.9% and 5-yr OS was 71.9±1.7%. 5-yr EFS and OS for pts ≥18 months of age with stage 4 disease (n = 746) were 58.4±2.3% and 71.0±2.1%. 5-yr EFS and OS were 82.3±4.8% and 86.7±4.2% among pts with stage 3 disease (n = 110). EFS but not OS was superior for those with a CR/VGPR pre-ASCT vs. PR (5-yr EFS: 64.2±2.2% vs. 55.4±3.2%, p = 0.0133; OS: 72.7±2.1% vs. 70.5±2.9%, p = 0.3811). There was a trend toward improved OS for those treated with tandem vs. single transplant (5-yr EFS: 65.9±4.3% vs. 60.4±2.1%, p = 0.1282; OS: 76.5±3.8% vs. 71.2±1.9%, p = 0.0704). Grade ≥3 toxicities ( > 10% of pts) during GM-CSF and IL-2-containing cycles, respectively, included pain (15.6/11.4%), fever (15.1/32.7%), anemia (18.9/21.7%), thrombocytopenia (13.9/17.4%), lymphopenia (12.3/16.0%), and hypokalemia (13.3/25.2%). Additional Grade ≥3 toxicities ( > 10% of pts) included hypoxia (10.1%) during GM-CSF-containing cycles, and anaphylaxis (12.0%), neutropenia (16.1%), hyponatremia (16.5%), and hypotension (13.8%) during IL-2-containing cycles. Conclusions: In this large cohort of HRNBL pts treated with immunotherapy, 5-yr EFS was 61.1%. Superior EFS was observed for pts with stage 3 disease and for those with CR/VGPR pre-ASCT. IL-2-containing cycles were associated with increased toxicity. Clinical trial information: NCT00026312.

Irinotecan, Temozolomide, and Dinutuximab With GM-CSF in Children With Refractory or Relapsed Neuroblastoma: A Report From the Children's Oncology Group

PURPOSE

The combination of irinotecan, temozolomide, dintuximab, and granulocyte-macrophage colony-stimulating factor (I/T/DIN/GM-CSF) demonstrated activity in patients with relapsed/refractory neuroblastoma in the randomized Children's Oncology Group ANBL1221 trial. To more accurately assess response rate and toxicity, an expanded cohort was nonrandomly assigned to I/T/DIN/GM-CSF.

PATIENTS AND METHODS

Patients were eligible at first relapse or first designation of refractory disease. Oral T and intravenous (IV) irinotecan were administered on days 1 to 5 of 21-day cycles. DIN was administered IV (days 2-5), and GM-CSF was administered subcutaneously (days 6-12). The primary end point was objective response, analyzed on an intent-to-treat basis per the International Neuroblastoma Response Criteria.

RESULTS

Seventeen eligible patients were randomly assigned to I/T/DIN/GM-CSF (February 2013 to March 2015); 36 additional patients were nonrandomly assigned to I/T/DIN/GM-CSF (August 2016 to May 2017). Objective (complete or partial) responses were observed in nine (52.9%) of 17 randomly assigned patients (95% CI, 29.2% to 76.7%) and 13 (36.1%) of 36 expansion patients (95% CI, 20.4% to 51.8%). Objective responses were seen in 22 (41.5%) of 53 patients overall (95% CI, 28.2% to 54.8%); stable disease was also observed in 22 of 53. One-year progression-free and overall survival for all patients receiving I/T/DIN/GM-CSF were 67.9% ± 6.4% (95% CI, 55.4% to 80.5%) and 84.9% ± 4.9% (95% CI, 75.3% to 94.6%), respectively. Two patients did not receive protocol therapy and were evaluable for response but not toxicity. Common grade ≥ 3 toxicities were fever/infection (18 [35.3%] of 51), neutropenia (17 [33.3%] of 51), pain (15 [29.4%] of 51), and diarrhea (10 [19.6%] of 51). One patient met protocol-defined criteria for unacceptable toxicity (grade 4 hypoxia). Higher DIN trough levels were associated with response.

CONCLUSION

I/T/DIN/GM-CSF has significant antitumor activity in patients with relapsed/refractory neuroblastoma. Study of chemoimmunotherapy in the frontline setting is indicated, as is further evaluation of predictive biomarkers.

The ganglioside GD2 as a circulating tumor biomarker for neuroblastoma

BACKGROUND

G_D2 is a ganglioside that is ubiquitously expressed in the plasma membrane of neuroblastoma and is shed into the circulation.

PROCEDURE

G_D2 was measured with a high-pressure liquid chromatography/tandem mass spectrometry assay in serum or plasma from 40 children without cancer (controls) and in biobanked samples from 128 (73 high-risk) children with neuroblastic tumors at diagnosis, 56 children with relapsed neuroblastoma, 14 children with high-risk neuroblastoma after treatment, and 8 to 12 children each with 10 other common childhood cancers at diagnosis.

RESULTS

The C₁₈ (18 carbon fatty acid) lipoform was the predominant circulating form of G_D2 in controls and in patients with neuroblastoma. The median concentration of G_D2 in children with high-risk neuroblastoma at diagnosis was 167 nM (range, 16.1-1060 nM), which was 30-fold higher than the median concentration (5.6 nM) in controls. G_D2 was not elevated in serum from children with the differentiated neuroblastic tumors, ganglioneuroma (n = 10) and ganglioneuroblastoma-intermixed subtype (n = 12), and in children with 10 other childhood cancers. G_D2 concentrations were significantly higher in serum from children with MYCN-amplified tumors (P = 0.0088), high-risk tumors (P < 0.00001), International Neuroblastoma Staging System (INSS) stage 4 tumors (P < 0.00001), and in children who died (P = 0.034).

CONCLUSIONS

Circulating G_D2 appears to be a specific and sensitive tumor biomarker for high-risk/high-stage neuroblastoma and may prove to be clinically useful as a diagnostic or prognostic circulating tumor biomarker. G_D2 will be measured prospectively and longitudinally in children enrolled on a high-risk neuroblastoma treatment trial to assess its ability to measure response to treatment and predict survival.

Sclerosing Epithelioid Fibrosarcoma of the Bone With Rare EWSR1-CREB3L3 Translocation Driving Upregulation of the PI3K/mTOR Signaling Pathway

Sclerosing epithelioid fibrosarcoma (SEF) is an uncommon neoplasm that rarely presents in bone. It is characterized by epithelioid cells arranged in nests and single-file cords within a sclerotic stromal background which may mimic neoplastic bone. SEF harbors an EWSR1 translocation, which may complicate its distinction from Ewing sarcoma in cases with histomorphologic overlap. We present a diagnostically challenging case of SEF in the mandible of a 16-year-old girl. Our experience highlights the lack of specificity of traditional morphology and EWSR1 break-apart fluorescent in situ hybridization. Open-ended RNA-based fusion gene testing coupled with MUC4 immunohistochemistry aided the eventual diagnosis in this case. Herein, we report the third case of SEF with EWSR1-CREB3L3 translocation and show that this fusion leads to aberrant upregulation of the phosphoinositide 3-kinase/mammalian target of rapamycin signaling pathway in heterologous cell models.

Unrealistic parental expectations for cure in poor-prognosis childhood cancer

BACKGROUND

Many parents of children with advanced cancer pursue curative goals when cure is no longer possible. To the authors' knowledge, no pediatric studies to date have prospectively evaluated prognosis communication or influences on decision making in poor-prognosis childhood cancer.

METHODS

The authors conducted a prospective cohort study at 9 pediatric cancer centers that enrolled 95 parents of children with recurrent or refractory, high-risk neuroblastoma (63% of those who were approached), a condition for which cure rarely is achieved. Parents were surveyed regarding the child's likelihood of cure; their primary goal of care; the child's symptoms, suffering, and quality of life; and regret concerning the last treatment decision. Medical records identified care and treatment decisions.

RESULTS

Only 26% of parents recognized that the chance of cure was <25%. When asked to choose a single most important goal of care, approximately 72% chose cure, 10% chose longer life, and 18% chose quality of life. Parents were more likely to prioritize quality of life when they recognized the child's poor prognosis (P = .002). Approximately 41% of parents expressed regret about the most recent treatment decision. Parents were more likely to experience regret if the child had received higher intensity medical care (odds ratio [OR], 3.14; 95% CI, 1.31-7.51), experienced suffering with limited benefit from the most recent treatment (OR, 4.78; 95% CI, 1.16-19.72), or experienced suffering from symptoms (OR, 2.91; 95% CI, 1.18-7.16).

CONCLUSIONS

Parents of children with poor-prognosis cancer frequently make decisions based on unrealistic expectations. New strategies for effective prognosis communication are needed.