Publications by authors named "Eva Dombi"

63 Publications

NF106: A Neurofibromatosis Clinical Trials Consortium Phase II Trial of the MEK Inhibitor Mirdametinib (PD-0325901) in Adolescents and Adults With NF1-Related Plexiform Neurofibromas.

J Clin Oncol 2021 Mar 28;39(7):797-806. Epub 2021 Jan 28.

Children's Hospital of Philadelphia, Philadelphia, PA.

Purpose: Patients with neurofibromatosis type 1 (NF1) frequently develop plexiform neurofibromas (PNs), which can cause significant morbidity. We performed a phase II trial of the MAPK/ERK kinase inhibitor, mirdametinib (PD-0325901), in patients with NF1 and inoperable PNs. The primary objective was response rate based on volumetric magnetic resonance imaging analysis.

Methods: Inclusion criteria included age ≥ 16 years and a PN that was either progressive or causing significant morbidity. First-dose pharmacokinetics were performed. Patients completed patient-reported outcome measures. Patients received mirdametinib by mouth twice a day at 2 mg/m/dose (maximum dose = 4 mg twice a day) in a 3-week on/1-week off sequence. Each course was 4 weeks in duration. Evaluations were performed after four courses for the first year and then after every six courses. Patients could receive a maximum of 24 total courses.

Results: Nineteen patients were enrolled, and all 19 received mirdametinib. The median age was 24 years (range, 16-39 years); the median baseline tumor volume was 363.8 mL (range, 3.9-5,161 mL). Eight of the 19 patients (42%) achieved a partial response of the target PN by course 12, and 10 (53%) had stable disease. One patient (5%) developed progressive disease at course 8. Significant and durable decreases were observed in pain ratings.

Conclusion: To our knowledge, this analysis represents the first characterization of the activity and pharmacokinetics of mirdametinib in patients with NF1 and PNs and is the first published response study for MAPK/ERK kinase inhibitors in adults with NF1 and PNs. Mirdametinib given at 2 mg/m/dose (maximum dose, 4 mg) twice daily in a 3-week on/1-week off sequence resulted in a 42% partial response rate with preliminary evidence of reduction in pain.
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http://dx.doi.org/10.1200/JCO.20.02220DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8078274PMC
March 2021

Cabozantinib for neurofibromatosis type 1-related plexiform neurofibromas: a phase 2 trial.

Nat Med 2021 01 13;27(1):165-173. Epub 2021 Jan 13.

Department of Neurology, Johns Hopkins University, Baltimore, MD, USA.

Neurofibromatosis type 1 (NF1) plexiform neurofibromas (PNs) are progressive, multicellular neoplasms that cause morbidity and may transform to sarcoma. Treatment of Nf1;Postn-Cre mice with cabozantinib, an inhibitor of multiple tyrosine kinases, caused a reduction in PN size and number and differential modulation of kinases in cell lineages that drive PN growth. Based on these findings, the Neurofibromatosis Clinical Trials Consortium conducted a phase II, open-label, nonrandomized Simon two-stage study to assess the safety, efficacy and biologic activity of cabozantinib in patients ≥16 years of age with NF1 and progressive or symptomatic, inoperable PN ( NCT02101736 ). The trial met its primary outcome, defined as ≥25% of patients achieving a partial response (PR, defined as ≥20% reduction in target lesion volume as assessed by magnetic resonance imaging (MRI)) after 12 cycles of therapy. Secondary outcomes included adverse events (AEs), patient-reported outcomes (PROs) assessing pain and quality of life (QOL), pharmacokinetics (PK) and the levels of circulating endothelial cells and cytokines. Eight of 19 evaluable (42%) trial participants achieved a PR. The median change in tumor volume was 15.2% (range, +2.2% to -36.9%), and no patients had disease progression while on treatment. Nine patients required dose reduction or discontinuation of therapy due to AEs; common AEs included gastrointestinal toxicity, hypothyroidism, fatigue and palmar plantar erythrodysesthesia. A total of 11 grade 3 AEs occurred in eight patients. Patients with PR had a significant reduction in tumor pain intensity and pain interference in daily life but no change in global QOL scores. These data indicate that cabozantinib is active in NF1-associated PN, resulting in tumor volume reduction and pain improvement.
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http://dx.doi.org/10.1038/s41591-020-01193-6DOI Listing
January 2021

MicroRNA-155 contributes to plexiform neurofibroma growth downstream of MEK.

Oncogene 2021 Feb 8;40(5):951-963. Epub 2020 Dec 8.

Division of Experimental Hematology and Cancer Biology, Cancer & Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH, 45229, USA.

MicroRNAs (miRs) are small non-coding RNAs that can have large impacts on oncogenic pathways. Possible functions of dysregulated miRs have not been studied in neurofibromatosis type 1 (NF1) plexiform neurofibromas (PNFs). In PNFs, Schwann cells (SCs) have biallelic NF1 mutations necessary for tumorigenesis. We analyzed a miR microarray comparing with normal and PNF SCs and identified differences in miR expression, and we validated in mouse PNFs versus normal mouse SCs by qRT-PCR. Among these, miR-155 was a top overexpressed miR, and its expression was regulated by RAS/MAPK signaling. Overexpression of miR-155 increased mature Nf1 mouse SC proliferation. In SC precursors, which model tumor-initiating cells, pharmacological and genetic inhibition of miR-155 decreased PNF-derived sphere numbers in vitro, and we identified Maf as a miR-155 target. In vivo, global deletion of miR-155 significantly decreased tumor number and volume, increasing mouse survival. Fluorescent nanoparticles entered PNFs, suggesting that an anti-miR might have therapeutic potential. However, treatment of established PNFs using anti-miR-155 peptide nucleic acid-loaded nanoparticles marginally decreased tumor numbers and did not reduce tumor growth. These results suggest that miR-155 plays a functional role in PNF growth and/or SC proliferation, and that targeting neurofibroma miRs is feasible, and might provide novel therapeutic opportunities.
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http://dx.doi.org/10.1038/s41388-020-01581-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7867646PMC
February 2021

Pediatric PK/PD Phase I Trial of Pexidartinib in Relapsed and Refractory Leukemias and Solid Tumors Including Neurofibromatosis Type I-Related Plexiform Neurofibromas.

Clin Cancer Res 2020 12 17;26(23):6112-6121. Epub 2020 Sep 17.

Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland.

Purpose: Simultaneously targeting the tumor and tumor microenvironment may hold promise in treating children with refractory solid tumors. Pexidartinib, an oral inhibitor of tyrosine kinases including colony stimulating factor 1 receptor (CSF-1R), KIT, and FLT3, is FDA approved in adults with tenosynovial giant cell tumor. A phase I trial was conducted in pediatric and young adult patients with refractory leukemias or solid tumors including neurofibromatosis type 1-related plexiform neurofibromas.

Patients And Methods: A rolling six design with dose levels (DL) of 400 mg/m, 600 mg/m, and 800 mg/m once daily for 28-day cycles (C) was used. Response was assessed at regular intervals. Pharmacokinetics and population pharmacokinetics were analyzed during C1.

Results: Twelve patients (4 per DL, 9 evaluable) enrolled on the dose-escalation phase and 4 patients enrolled in the expansion cohort: median (lower, upper quartile) age 16 (14, 16.5) years. No dose-limiting toxicities were observed. Pharmacokinetics appeared linear over three DLs. Pharmacokinetic modeling and simulation determined a weight-based recommended phase II dose (RP2D). Two patients had stable disease and 1 patient with peritoneal mesothelioma (C49+) had a sustained partial response (67% RECIST reduction). Pharmacodynamic markers included a rise in plasma macrophage CSF (MCSF) levels and a decrease in absolute monocyte count.

Conclusions: Pexidartinib in pediatric patients was well tolerated at all DL tested, achieved target inhibition, and resulted in a weight-based RPD2 dose.
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http://dx.doi.org/10.1158/1078-0432.CCR-20-1696DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7909006PMC
December 2020

The MEK inhibitor selumetinib reduces spinal neurofibroma burden in patients with NF1 and plexiform neurofibromas.

Neurooncol Adv 2020 Jan-Dec;2(1):vdaa095. Epub 2020 Aug 8.

Pediatric Oncology Branch, National Cancer Institute, Center for Cancer Research, Bethesda, Maryland, USA.

Background: Spinal neurofibromas (SNFs) in neurofibromatosis type 1 (NF1) can cause progressive spinal cord compression and neurological dysfunction. The MEK inhibitor selumetinib shrinks the majority of plexiform neurofibromas (PNs) in patients with NF1. We assessed the effect of selumetinib on SNF.

Methods: Pediatric and adult patients with NF1 and inoperable PN participating in phase 2 studies of selumetinib for PN were included in this analysis if they had SNF and serial spine magnetic resonance imaging (MRI). Selumetinib was administered orally at the recommended dose of 25 mg/m/dose twice daily (max 50 mg b.i.d.; 1 cycle = 28 days). We qualitatively assessed the effect of selumetinib on SNF-related spinal canal distortion, cerebrospinal fluid distribution, and spinal cord deformity on MRI.

Results: Twenty-four patients (18 male), median age 16.9 years (range, 6.2-60.3), had SNF, 22 of which were associated with the same nerves as the target PN assessed on the clinical trial. Twenty patients had spinal cord deformity. Twenty-three patients completed at least 12 treatment cycles to date. Eighteen patients showed subtle to a marked improvement in SNF burden, 5 remained stable, and no worsening was observed during treatment.

Conclusions: This is the first study describing the effect of selumetinib on SNF. Of 24 patients, 18 exhibited some improvement of SNF burden on imaging. These findings suggest that selumetinib may prevent the worsening of cord compression, potentially reducing the need for surgical interventions in select patients or benefitting patients who do not have a surgical option. Prospective evaluation of the clinical benefit of selumetinib for SNF is warranted.
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http://dx.doi.org/10.1093/noajnl/vdaa095DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7486535PMC
August 2020

Are Some Randomized Clinical Trials Impossible?

J Pediatr Orthop 2021 Jan;41(1):e90-e93

Human Genetics, Cincinnati Children's Hospital, Cincinnati, OH.

Congenital tibial pseudarthrosis is a rare condition seen in neurofibromatosis type 1 (NF1), and treatment is complex. A randomized, placebo-controlled trial of bone morphogenetic protein (rhBMP-2; INFUSE bone graft) at time of tibial surgery was developed by the Neurofibromatosis Clinical Trials Consortium. Patients were randomized to receive rhBMP-2 that would, or would not, be added to the standard surgical procedure consisting of resection of pseudarthrosis tissue, insertion of a rigid intramedullary rod, and placement of autogenous iliac crest bone graft. Despite involvement of 16 centers with wide experience with NF1 orthopaedic management, only 5 patients (of 54 required) were able to be enrolled in the study during a 3-year time period. Because of the inability to recruit sufficient patients, this study was closed in June 2019, with plans to terminate. The obstacles that were encountered during the study are summarized. The authors question whether a randomized, placebo-controlled trial of a rare pediatric orthopaedic condition is possible to accomplish. Recommendations are provided to guide future studies of orthopaedic manifestations of NF1.Level of Evidence: Level V.
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http://dx.doi.org/10.1097/BPO.0000000000001650DOI Listing
January 2021

Loss in a Model of Neurofibroma Demonstrates Stepwise Tumor Progression to Atypical Neurofibroma and MPNST.

Cancer Res 2020 11 19;80(21):4720-4730. Epub 2020 Aug 19.

Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio.

Plexiform neurofibromas are benign nerve sheath Schwann cell tumors characterized by biallelic mutations in the neurofibromatosis type 1 (NF1) tumor suppressor gene. Atypical neurofibromas show additional frequent loss of CDKN2A/Ink4a/Arf and may be precursor lesions of aggressive malignant peripheral nerve sheath tumors (MPNST). Here we combined loss of Nf1 in developing Schwann cells with global Ink4a/Arf loss and identified paraspinal plexiform neurofibromas and atypical neurofibromas. Upon transplantation, atypical neurofibromas generated genetically engineered mice (GEM)-PNST similar to human MPNST, and tumors showed reduced p16INK4a protein and reduced senescence markers, confirming susceptibility to transformation. Superficial GEM-PNST contained regions of nerve-associated plexiform neurofibromas or atypical neurofibromas and grew rapidly on transplantation. Transcriptome analyses showed similarities to corresponding human tumors. Thus, we recapitulated nerve tumor progression in NF1 and provided preclinical platforms for testing therapies at each tumor grade. These results support a tumor progression model in which loss of NF1 in Schwann cells drives plexiform neurofibromas formation, additional loss of Ink4a/Arf contributes to atypical neurofibromas formation, and further changes underlie transformation to MPNST. SIGNIFICANCE: New mouse models recapitulate the stepwise progression of NF1 tumors and will be useful to define effective treatments that halt tumor growth and tumor progression in NF1.
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http://dx.doi.org/10.1158/0008-5472.CAN-19-1429DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7968129PMC
November 2020

Current status of MEK inhibitors in the treatment of plexiform neurofibromas.

Childs Nerv Syst 2020 10 30;36(10):2443-2452. Epub 2020 Jun 30.

Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, 10 Center Drive, Building 10, Room 1-3752, Bethesda, MD, 20892, USA.

Background: Neurofibromatosis type 1 (NF1)-related plexiform neurofibromas (pNF) can be debilitating and until recently, surgery was the only potentially effective therapy for these tumors.

Methods: We review critical steps in the path towards the FDA approval of the first medical therapy for NF1 pNF and the current status of MEK inhbitor therapy.

Results: Sustained efforts by the NF community have resulted in a detailed understanding of the natural history and biology of NF1-related peripheral nerve sheath tumors. This work provided the basis for the development of meaningful clinical trials targeting pNF. Inhibition of the RAS/MAPK signaling pathway with MEK inhibitors identified the first medical therapy which resulted in shrinkage in the majority of children with NF1 and large inoperable pNF. Based on this finding and subsequent demonstration of clinical benefit, the MEK inhibitor selumetinib recently received approval by the United States Food and Drug Administration (FDA) for children with symptomatic pNF.

Conclusions: Sustained efforts and collaborations have resulted in identification of MEK inhibitors as effective therapy for NF1 pNF. Future work work will be directed at prevention of pNF morbidity and deepening the reponse in symptomatic pNF.
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http://dx.doi.org/10.1007/s00381-020-04731-2DOI Listing
October 2020

A molecular basis for neurofibroma-associated skeletal manifestations in NF1.

Genet Med 2020 11 30;22(11):1786-1793. Epub 2020 Jun 30.

Department of Molecular and Human Genetics and Orthopaedic Surgery, Baylor College of Medicine, Houston, TX, USA.

Purpose: Plexiform neurofibromas (pNF) develop in children with neurofibromatosis type 1 (NF1) and can be associated with several skeletal comorbidities. Preclinical mouse studies revealed Nf1 deficiency in osteoprogenitor cells disrupts, in a MEK-dependent manner, pyrophosphate (PPi) homeostasis and skeletal mineralization. The etiology of NF-associated skeletal manifestations remains unknown.

Methods: We used mouse models of NF1 neurofibromas to assess bone mineralization of skeletal structures adjacent to tumors. Expression of genes involved in pyrophosphate homeostasis was assessed in mouse and human NF tumors and Schwann cell cultures. We used dual-energy X-ray absorptiometry (DXA) to assess tumor-associated changes in bone mineral density (BMD) in an individual with NF1 following treatment with the MEK inhibitor selumetinib.

Results: We detected increased nonmineralized bone surfaces adjacent to tumors in mouse models of NF1 neurofibromas. Expression of Enpp1, a PPi-generating ectophosphatase, and ANKH, a PPi transporter, was increased in mouse and human neurofibroma-derived tissues and Schwann cells, respectively. In one patient, tumor-associated reductions in BMD were partially rescued following therapy with selumetinib.

Conclusion: Results indicate that NF-associated skeletal pathologies in NF1 are associated with dysregulated pyrophosphate homeostasis in adjacent NF tumors and suggest that treatment of NFs with MEK inhibitors may improve skeletal manifestations of the disease.
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http://dx.doi.org/10.1038/s41436-020-0885-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8106869PMC
November 2020

Selumetinib in Children with Inoperable Plexiform Neurofibromas.

N Engl J Med 2020 04 18;382(15):1430-1442. Epub 2020 Mar 18.

From the Pediatric Oncology Branch (A.M.G., P.L.W., E.D., P.W., S.M., M.C.R., D.C.P., A.C., J.T., O.K., J.G., B.C.W.) and the Clinical Pharmacology Program (C.J.P., W.D.F.), Center for Cancer Research, National Cancer Institute, and the Rehabilitation Medicine Department, Clinical Center (S.M.P), National Institutes of Health, Bethesda, the Clinical Monitoring Research Program Directorate, Frederick National Laboratory for Cancer Research, National Cancer Institute, Frederick (A.B., K.H.), the Cancer Therapy Evaluation Program (M.S., L.A.D.) and the Biostatistics and Data Management Section, Center for Cancer Research (S.M.S., D.J.V.), National Cancer Institute, National Institutes of Health, Shady Grove, and Johns Hopkins University School of Medicine, Baltimore (J.O.B.) - all in Maryland; Children's Hospital of Philadelphia, Philadelphia (M.J.F., A.C.S.); Cincinnati Children's Hospital, Cincinnati (B.W.); Children's National Hospital, Washington, DC (A.K., M.B.); and Indiana University School of Medicine, Indianapolis (D.W.C., C.Z.).

Background: No approved therapies exist for inoperable plexiform neurofibromas in patients with neurofibromatosis type 1.

Methods: We conducted an open-label, phase 2 trial of selumetinib to determine the objective response rate among patients with plexiform neurofibromas and to assess clinical benefit. Children with neurofibromatosis type 1 and symptomatic inoperable plexiform neurofibromas received oral selumetinib twice daily at a dose of 25 mg per square meter of body-surface area on a continuous dosing schedule (28-day cycles). Volumetric magnetic resonance imaging and clinical outcome assessments (pain, quality of life, disfigurement, and function) were performed at least every four cycles. Children rated tumor pain intensity on a scale from 0 (no pain) to 10 (worst pain imaginable).

Results: A total of 50 children (median age, 10.2 years; range, 3.5 to 17.4) were enrolled from August 2015 through August 2016. The most frequent neurofibroma-related symptoms were disfigurement (44 patients), motor dysfunction (33), and pain (26). A total of 35 patients (70%) had a confirmed partial response as of March 29, 2019, and 28 of these patients had a durable response (lasting ≥1 year). After 1 year of treatment, the mean decrease in child-reported tumor pain-intensity scores was 2 points, considered a clinically meaningful improvement. In addition, clinically meaningful improvements were seen in child-reported and parent-reported interference of pain in daily functioning (38% and 50%, respectively) and overall health-related quality of life (48% and 58%, respectively) as well as in functional outcomes of strength (56% of patients) and range of motion (38% of patients). Five patients discontinued treatment because of toxic effects possibly related to selumetinib, and 6 patients had disease progression. The most frequent toxic effects were nausea, vomiting, or diarrhea; an asymptomatic increase in the creatine phosphokinase level; acneiform rash; and paronychia.

Conclusions: In this phase 2 trial, most children with neurofibromatosis type 1 and inoperable plexiform neurofibromas had durable tumor shrinkage and clinical benefit from selumetinib. (Funded by the Intramural Research Program of the National Institutes of Health and others; ClinicalTrials.gov number, NCT01362803.).
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http://dx.doi.org/10.1056/NEJMoa1912735DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7305659PMC
April 2020

Longitudinal evaluation of peripheral nerve sheath tumors in neurofibromatosis type 1: growth analysis of plexiform neurofibromas and distinct nodular lesions.

Neuro Oncol 2020 09;22(9):1368-1378

Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute (NCI), National Institutes of Health (NIH), Bethesda, Maryland.

Background: Understanding the natural history of non-malignant peripheral nerve sheath tumors (PNSTs) in neurofibromatosis type 1 (NF1) is critical to optimal clinical care and the development of meaningful clinical trials.

Methods: We longitudinally analyzed growth of plexiform neurofibromas (PNs) and of PNSTs with distinct nodular appearance (distinct nodular lesions [DNLs]) using volumetric MRI analysis in patients enrolled on a natural history study (NCT00924196).

Results: DNLs were observed in 58/122 (45.6%) patients (median 2 DNLs/patient). In DNLs that developed during follow-up, median age of development was 17 years. A moderate negative correlation was observed between the estimated PN growth rate and patients' age at initial MRI (Spearman's r [95% CI]: -0.60 [-0.73, -0.43], n = 70), whereas only a weak correlation was observed for DNLs (Spearman's r [95% CI]: -0.25 [-0.47, 0.004]; n = 61). We observed a moderate negative correlation between tumor growth rate and baseline tumor volume for PNs and DNLs (Spearman's r [95% CI]: -0.52 [-0.67, -0.32] and -0.61 [-0.75, -0.42], respectively). Spontaneous tumor volume reduction was observed in 10 PNs and 7 DNLs (median decrease per year, 3.6% and 7.3%, respectively).

Conclusion: We corroborate previously described findings that most rapidly growing PNs are observed in young children. DNLs tend to develop later in life and their growth is minimally age related. Distinct growth characteristics of PNs and DNLs suggest that these lesions have a different biology and may require different clinical management and clinical trial design. In a subset of PNs and DNLs, slow spontaneous regression in tumor volume was seen.
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http://dx.doi.org/10.1093/neuonc/noaa053DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7523449PMC
September 2020

Safe marginal resection of atypical neurofibromas in neurofibromatosis type 1.

J Neurosurg 2019 Oct 25:1-11. Epub 2019 Oct 25.

1Surgical Neurology Branch.

Objective: Patients with neurofibromatosis type 1 (NF1) are predisposed to visceral neurofibromas, some of which can progress to premalignant atypical neurofibromas (ANFs) and malignant peripheral nerve sheath tumors (MPNSTs). Though subtotal resection of ANF may prevent malignant transformation and thus deaths with no neural complications, local recurrences require reoperation. The aim of this study was to assess the surgical morbidity associated with marginal resection of targeted ANF nodules identified via preoperative serial volumetric MRI and 18F-FDG-PET imaging.

Methods: The authors analyzed clinical outcomes of 16 NF resections of 21 tumors in 11 NF1 patients treated at the NIH Clinical Center between 2008 and 2018. Preoperative volumetric growth rates and 18F-FDG-PET SUVMax (maximum standardized uptake value within the tumor) of the target lesions and any electromyographic or nerve conduction velocity abnormalities of the parent nerves were measured and assessed in tandem with postoperative complications, histopathological classification of the resected tumors, and surgical margins through Dunnett's multiple comparisons test and t-test. The surgical approach for safe marginal resection of ANF was also described.

Results: Eleven consecutive NF1 patients (4 male, 7 female; median age 18.5 years) underwent 16 surgical procedures for marginal resections of 21 tumors. Preoperatively, 13 of the 14 (93%) sets of serial MRI studies and 10 of the 11 (91%) 18F-FDG-PET scans showed rapid growth (≥ 20% increase in volume per year) and avidity (SUVMax ≥ 3.5) of the identified tumor, respectively (median tumor size 48.7 cm3; median growth rate 92% per year; median SUVMax 6.45). Most surgeries (n = 14, 88%) resulted in no persistent postoperative parent nerve-related complications, and to date, none of the resected tumors have recurred. The median length of postoperative follow-up has been 2.45 years (range 0.00-10.39 years). Histopathological analysis confirmed significantly greater SUVMax among the ANFs (6.51 ± 0.83, p = 0.0042) and low-grade MPNSTs (13.8, p = 0.0001) than in benign neurofibromas (1.9).

Conclusions: This report evaluates the utility of serial imaging (MRI and 18F-FDG-PET SUVMax) to successfully detect ANF and demonstrates that safe, fascicle-sparing gross-total, extracapsular resection of ANF is possible with the use of intraoperative nerve stimulation and microdissection of nerve fascicles.
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http://dx.doi.org/10.3171/2019.7.JNS191353DOI Listing
October 2019

Cediranib phase-II study in children with metastatic alveolar soft-part sarcoma (ASPS).

Pediatr Blood Cancer 2019 12 10;66(12):e27987. Epub 2019 Sep 10.

Pediatric Oncology Branch, National Cancer Institute, Bethesda, Maryland.

Background: Alveolar soft-part sarcoma (ASPS), a rare vascular sarcoma with a clinically indolent course, frequently presents with metastases. Vascular endothelial growth factor (VEGF) is a promising therapeutic target. In a phase-II trial of the VEGF receptor inhibitor cediranib for adults with ASPS, the partial response (PR) rate (response evaluation criteria in solid tumors [RECIST] v1.0) was 35% (15/43; 95% confidence interval: 21-51%). We evaluated cediranib in the pediatric population.

Procedure: Patients <16 years old with metastatic, unresectable ASPS received cediranib at the pediatric maximum tolerated dose of 12 mg/m (≈70% of the fixed adult phase-II dose orally daily). Tumor response was assessed every two cycles (RECIST v1.0). A Simon two-stage optimal design (target response rate 35%, rule out 5%) was used.

Results: Seven patients (four females), with a median age of 13 years, (range 9-15), were enrolled on stage 1. The most frequent grade 2 or 3 adverse events were neutropenia, diarrhea, hypertension, fatigue, and proteinuria. The best response was stable disease (SD) (median cycle number = 34). Three patients were removed from the study treatment for disease progression (cycles 4, 5, and 36). Five of seven patients had SD for ≥14 months. Two patients with SD remain on study (34-57+ cycles).

Conclusions: Cediranib did not reach the target response rate in this small pediatric cohort, in contrast to the adult 35% PR rate. The pediatric dosing was 30% lower compared to the adult dosing, which may have contributed to response differences. Prolonged SD was observed in five patients, but given the indolent nature of ASPS, SD cannot be clearly attributed to cediranib. Cediranib has an acceptable safety profile.
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http://dx.doi.org/10.1002/pbc.27987DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6803032PMC
December 2019

A Phase II Trial of Vandetanib in Children and Adults with Succinate Dehydrogenase-Deficient Gastrointestinal Stromal Tumor.

Clin Cancer Res 2019 11 22;25(21):6302-6308. Epub 2019 Aug 22.

Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland.

Purpose: Gastrointestinal stromal tumors (GIST) are resistant to cytotoxic chemotherapy and radiotherapy. Most GIST in children are wild-type for and (WT GIST) and deficient in expression of succinate dehydrogenase (dSDH GIST). We tested the activity of vandetanib, an oral small-molecule inhibitor of VEGFR2, EGFR, and RET, in patients with dSDH GIST.

Patients And Methods: Phase II study of vandetanib (300 mg orally once daily to patients ≥18 years, and 100 mg/m/dose to patients < 18 years) on a continuous dosing schedule (1 cycle = 28 days) to assess the clinical activity (partial and complete response rate RECIST v1.1) in patients with dSDH GIST. A Simon optimal two-stage design (target response rate 25%, rule out 5%) was used: If ≥1 of 9 patients in stage 1 responded, enrollment would be expanded to 24 patients, and if ≥3 of 24 responded, vandetanib would be considered active.

Results: Nine patients (7 female and 2 male; median age, 24 years; range, 11-52) with metastatic disease were enrolled. Three of the initial 5 adult patients developed treatment-modifying toxicities. After a protocol amendment, two adults received vandetanib at 200 mg/dose with improved tolerability. The two children (<18 years old) enrolled did not experience treatment-modifying toxicities. No partial or complete responses were observed (median number of cycles, 4; range, 2-18).

Conclusions: Vandetanib at a dose of 300 mg daily was not well tolerated by adults with dSDH GIST. Two of 9 patients had prolonged stable disease, but no partial or complete responses were observed, and vandetanib is thus not considered active in dSDH GIST.
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http://dx.doi.org/10.1158/1078-0432.CCR-19-0986DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6825553PMC
November 2019

Targeting Sporadic and Neurofibromatosis Type 1 (NF1) Related Refractory Malignant Peripheral Nerve Sheath Tumors (MPNST) in a Phase II Study of Everolimus in Combination with Bevacizumab (SARC016).

Sarcoma 2019 24;2019:7656747. Epub 2019 Jul 24.

Cincinnati Children's Hospital, 3333 Burnet Ave, Cincinnati, OH 45229, USA.

Purpose: There are no known effective medical treatments for refractory MPNST. Inactivation of the NF1 tumor suppressor in MPNST results in upregulation of mTOR (mammalian target of rapamycin) signaling and angiogenesis, which contributes to disease progression. We conducted a phase II study for patients (pts) with refractory MPNST combining everolimus (10 mg PO once daily) with bevacizumab (10 mg/kg IV every 2 weeks) to determine the clinical benefit rate (CBR) (complete response, partial response (PR), or stable disease (SD) ≥ 4 months).

Patients And Methods: Patients ≥18 years old with chemotherapy refractory sporadic or NF1 MPNST were eligible. Tumor response was assessed after every 2 cycles (the WHO criteria). A two-stage design targeting a 25% CBR was used: if ≥ 1/15 pts in stage 1 responded, enrollment would be expanded by 10 pts, and if ≥ 4/25 patients had clinical benefit, the combination would be considered active.

Results: Twenty-five pts, 17 with NF1 and 8 with sporadic MPNST, enrolled. One of 15 pts in stage 1 had clinical benefit. Of 10 additional pts enrolled, 2 had clinical benefit. The median number of completed cycles was 3 (range 1-16). Adverse events were similar to those known for this combination.

Conclusion: With a CBR of 12% (3/25), the combination of everolimus and bevacizumab did not reach the study's target response rate and is not considered active in refractory MPNST.
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http://dx.doi.org/10.1155/2019/7656747DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6681622PMC
July 2019

RUNX represses to drive neurofibromagenesis.

Sci Adv 2019 04 24;5(4):eaau8389. Epub 2019 Apr 24.

Cincinnati Children's Hospital Medical Center, Division of Experimental Hematology and Cancer Biology, Cancer and Blood Diseases Institute, University of Cincinnati, 3333 Burnet Ave., Cincinnati, OH 45229, USA.

Patients with neurofibromatosis type 1 (NF1) are predisposed to develop neurofibromas, but the underlying molecular mechanisms of neurofibromagenesis are not fully understood. We showed dual genetic deletion of and in Schwann cells (SCs) and SC precursors delayed neurofibromagenesis and prolonged mouse survival. We identified peripheral myelin protein 22 () related to neurofibroma initiation. Knockdown of with short hairpin RNAs increased tumor-derived sphere numbers and enabled significantly more neurofibroma-like microlesions on transplantation. Conversely, overexpression of in mouse neurofibroma SCs decreased cell proliferation. Mechanistically, RUNX1/3 regulated alternative promoter usage and induced levels of protein expression of to control SC growth. Last, pharmacological inhibition of RUNX/core-binding factor β (CBFB) activity significantly reduced neurofibroma volume in vivo. Thus, we identified a signaling pathway involving RUNX1/3 suppression of in neurofibroma initiation and/or maintenance. Targeting disruption of RUNX/CBFB interaction might provide a novel therapy for patients with neurofibroma.
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http://dx.doi.org/10.1126/sciadv.aau8389DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6482019PMC
April 2019

Pharmacodynamic Study of Miransertib in Individuals with Proteus Syndrome.

Am J Hum Genet 2019 03 22;104(3):484-491. Epub 2019 Feb 22.

Medical Genomics and Metabolic Genetics Branch, National Human Genome Research Institute, NIH, Bethesda, MD 20892, USA. Electronic address:

Proteus syndrome is a life-threatening segmental overgrowth syndrome caused by a mosaic gain-of-function AKT1 variant. There are no effective treatments for Proteus syndrome. Miransertib is an AKT1 inhibitor that, prior to this study, has been evaluated only in adult oncology trials. We designed a non-randomized, phase 0/1 pilot study of miransertib in adults and children with Proteus syndrome to identify an appropriate dosage starting point for a future efficacy trial using a pharmacodynamic endpoint. The primary endpoint was a 50% reduction in the tissue levels of AKT phosphorylation from biopsies in affected individuals. We also evaluated secondary efficacy endpoints. We found that a dose of 5 mg/m/day (1/7 the typical dose used in oncology) led to a 50% reduction in phosphorylated AKT (pAKT) in affected tissues from five of six individuals. This dose was well tolerated. Two of the six efficacy endpoints (secondary objectives) suggested that this agent may be efficacious. We observed a decrease in a cerebriform connective tissue nevus and a reduction in pain in children. We conclude that 5 mg/m/day of miransertib is an appropriate starting point for future efficacy trials and that this agent shows promise of therapeutic efficacy in children with Proteus syndrome.
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http://dx.doi.org/10.1016/j.ajhg.2019.01.015DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6407523PMC
March 2019

Cxcr3-expressing leukocytes are necessary for neurofibroma formation in mice.

JCI Insight 2019 Feb 7;4(3). Epub 2019 Feb 7.

Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.

Plexiform neurofibroma is a major contributor to morbidity in patients with neurofibromatosis type I (NF1). Macrophages and mast cells infiltrate neurofibroma, and data from mouse models implicate these leukocytes in neurofibroma development. Antiinflammatory therapy targeting these cell populations has been suggested as a means to prevent neurofibroma development. Here, we compare gene expression in Nf1-mutant nerves, which invariably form neurofibroma, and show disruption of neuron-glial cell interactions and immune cell infiltration to mouse models, which rarely progresses to neurofibroma with or without disruption of neuron-glial cell interactions. We find that the chemokine Cxcl10 is uniquely upregulated in NF1 mice that invariably develop neurofibroma. Global deletion of the CXCL10 receptor Cxcr3 prevented neurofibroma development in these neurofibroma-prone mice, and an anti-Cxcr3 antibody somewhat reduced tumor numbers. Cxcr3 expression localized to T cells and DCs in both inflamed nerves and neurofibromas, and Cxcr3 expression was necessary to sustain elevated macrophage numbers in Nf1-mutant nerves. To our knowledge, these data support a heretofore-unappreciated role for T cells and DCs in neurofibroma initiation.
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http://dx.doi.org/10.1172/jci.insight.98601DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6413799PMC
February 2019

Low mutation burden and frequent loss of CDKN2A/B and SMARCA2, but not PRC2, define premalignant neurofibromatosis type 1-associated atypical neurofibromas.

Neuro Oncol 2019 08;21(8):981-992

Clinical Genetics Branch, DCEG, NCI, National Institutes of Health (NIH), Rockville, Maryland, USA.

Background: Neurofibromatosis type 1 (NF1) is a tumor-predisposition disorder caused by germline mutations in NF1. NF1 patients have an 8-16% lifetime risk of developing a malignant peripheral nerve sheath tumor (MPNST), a highly aggressive soft-tissue sarcoma, often arising from preexisting benign plexiform neurofibromas (PNs) and atypical neurofibromas (ANFs). ANFs are distinct from both PN and MPNST, representing an intermediate step in malignant transformation.

Methods: In the first comprehensive genomic analysis of ANF originating from multiple patients, we performed tumor/normal whole-exome sequencing (WES) of 16 ANFs. In addition, we conducted WES of 3 MPNSTs, copy-number meta-analysis of 26 ANFs and 28 MPNSTs, and whole transcriptome sequencing analysis of 5 ANFs and 5 MPNSTs.

Results: We identified a low number of mutations (median 1, range 0-5) in the exomes of ANFs (only NF1 somatic mutations were recurrent), and frequent deletions of CDKN2A/B (69%) and SMARCA2 (42%). We determined that polycomb repressor complex 2 (PRC2) genes EED and SUZ12 were frequently mutated, deleted, or downregulated in MPNSTs but not in ANFs. Our pilot gene expression study revealed upregulated NRAS, MDM2, CCND1/2/3, and CDK4/6 in ANFs and MPNSTs, and overexpression of EZH2 in MPNSTs only.

Conclusions: The PN-ANF transition is primarily driven by the deletion of CDKN2A/B. Further progression from ANF to MPNST likely involves broad chromosomal rearrangements and frequent inactivation of the PRC2 genes, loss of the DNA repair genes, and copy-number increase of signal transduction and cell-cycle and pluripotency self-renewal genes.
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http://dx.doi.org/10.1093/neuonc/noz028DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6682216PMC
August 2019

STAT3 inhibition reduces macrophage number and tumor growth in neurofibroma.

Oncogene 2019 04 12;38(15):2876-2884. Epub 2018 Dec 12.

Department of Pediatrics, University of Cincinnati College of Medicine, Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital, 3333 Burnet Ave., Cincinnati, OH, 45229-0713, USA.

Plexiform neurofibroma, a benign peripheral nerve tumor, is associated with the biallelic loss of function of the NF1 tumor suppressor in Schwann cells. Here, we show that FLLL32, a small molecule inhibitor of JAK2/STAT3 signaling, reduces neurofibroma growth in mice with conditional, biallelic deletion of Nf1 in the Schwann cell lineage. FLLL32 treatment or Stat3 deletion in tumor cells reduced inflammatory cytokine expression and tumor macrophage numbers in neurofibroma. Although STAT3 inhibition downregulated the chemokines CCL2 and CCL12, which can signal through CCR2 to recruit macrophages to peripheral nerves, deletion of Ccr2 did not improve survival or reduce macrophage numbers in neurofibroma-bearing mice. Interestingly, Iba1+; F4/80+;CD11b+ macrophages accounted for ~20-40% of proliferating cells in untreated tumors. FLLL32 suppressed macrophage proliferation, implicating STAT3-dependent, local proliferation in neurofibroma macrophage accumulation, and decreased Schwann cell proliferation and increased Schwann cell death. The functions of STAT3 signaling in neurofibroma Schwann cells and macrophages, and its relevance as a therapeutic target in neurofibroma, merit further investigation.
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http://dx.doi.org/10.1038/s41388-018-0600-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6461477PMC
April 2019

Genetically engineered minipigs model the major clinical features of human neurofibromatosis type 1.

Commun Biol 2018 2;1:158. Epub 2018 Oct 2.

Recombinetics Inc., 1246 University Avenue W., Suite 301, St. Paul, MN, 55104, USA.

Neurofibromatosis Type 1 (NF1) is a genetic disease caused by mutations in (). NF1 patients present with a variety of clinical manifestations and are predisposed to cancer development. Many NF1 animal models have been developed, yet none display the spectrum of disease seen in patients and the translational impact of these models has been limited. We describe a minipig model that exhibits clinical hallmarks of NF1, including café au lait macules, neurofibromas, and optic pathway glioma. Spontaneous loss of heterozygosity is observed in this model, a phenomenon also described in NF1 patients. Oral administration of a mitogen-activated protein kinase/extracellular signal-regulated kinase inhibitor suppresses Ras signaling. To our knowledge, this model provides an unprecedented opportunity to study the complex biology and natural history of NF1 and could prove indispensable for development of imaging methods, biomarkers, and evaluation of safety and efficacy of NF1-targeted therapies.
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http://dx.doi.org/10.1038/s42003-018-0163-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6168575PMC
October 2018

Association of plexiform neurofibroma volume changes and development of clinical morbidities in neurofibromatosis 1.

Neuro Oncol 2018 11;20(12):1643-1651

Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health (NIH), Bethesda, Maryland.

Background: Plexiform neurofibromas (PN) in neurofibromatosis 1 (NF1) can cause substantial morbidities. Clinical trials targeting PN have recently described decreases in PN volumes. However, no previous study has assessed the association between changes in PN volumes and PN-related morbidities. Our objective was to assess if increasing PN volume in NF1 is associated with increasing PN-related morbidity.

Methods: This is a retrospective review of patients enrolled on the NCI NF1 natural history study with ≥7 years of data available. Morbidities including pain, motor dysfunction, vision loss, and PN-related surgery were assessed at time of baseline PN MRI with volumetric analysis and time of MRI with maximum PN volume.

Results: Forty-one patients (median age at baseline 8 y) with 57 PN were included. At baseline, 40 PN had at least 1 PN-associated morbidity. During the observation period, 27 PN required increasing pain medication, and these PN grew faster per year (median difference 8.3%; 95% CI: 2.4, 13.8%) than those PN which did not. PN resulting in motor impairment at baseline (n = 11) had larger volumes compared with those that did not (median difference 461 mL; 95% CI: 66.9, 820).

Conclusions: Many NF1 PN were associated with clinically significant morbidity at baseline, highlighting the need for longitudinal morbidity evaluations starting at an early age to capture changes in PN-associated morbidities. Prospective evaluation of standardized patient reported and functional outcomes in clinical trials are ongoing and may allow further characterization of the association of PN volume increase or decrease and clinical changes.
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http://dx.doi.org/10.1093/neuonc/noy067DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6231202PMC
November 2018

The characteristics of 76 atypical neurofibromas as precursors to neurofibromatosis 1 associated malignant peripheral nerve sheath tumors.

Neuro Oncol 2018 05;20(6):818-825

Neurofibromatosis Center, Department of Neurology, Guy's and St. Thomas' NHS Foundation Trust, London and King's College, London, England.

Background: Neurofibromatosis 1 (NF1) leads to the development of benign and malignant peripheral nerve sheath tumors (MPNST). MPNST have been described to develop in preexisting benign plexiform neurofibromas (PN) and have a poor prognosis. Atypical neurofibromas (ANF) were recently described as precursor lesions for MPNST, making early detection and management of ANF a possible strategy to prevent MPNST. We aimed to clinically characterize ANF and identify management approaches.

Methods: We analyzed clinical, imaging, and pathology findings of all patients with NF1 and ANF at 3 institutions.

Results: Sixty-three patients had 76 ANF (32M/31F; median age 27.1 y). On MRI, most ANF appeared as distinct nodular lesions and were 18F-fluorodeoxyglucose (FDG) avid. Forty-six ANF were associated with pain, 19 with motor weakness, 45 were palpable or visible, and 13 had no clinical signs. Completely resected ANF (N = 57) have not recurred (median follow-up, 4.1 y; range, 0-14 y). Four ANF transformed into MPNST and 17 patients had a history of MPNST in a different location than was their ANF.

Conclusions: Growth of distinct nodular lesions, pain, and FDG-PET avidity should raise concern for ANF in NF1. Patients with ANF are at greater risk for development of MPNST. Complete resection of ANF may prevent development of MPNST.
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http://dx.doi.org/10.1093/neuonc/noy013DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5961015PMC
May 2018

Outcomes of Children and Adolescents with Advanced Hereditary Medullary Thyroid Carcinoma Treated with Vandetanib.

Clin Cancer Res 2018 02 29;24(4):753-765. Epub 2017 Nov 29.

Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland.

Vandetanib is well-tolerated in patients with advanced medullary thyroid carcinoma (MTC). Long-term outcomes and mechanisms of MTC progression have not been reported previously. We monitored toxicities and disease status in patients taking vandetanib for hereditary, advanced MTC. Tumor samples were analyzed for molecular mechanisms of disease progression. Seventeen patients [8 male, age 13 (9-17)* years] enrolled; 16 had a p.Met918Thr germline mutation. The duration of vandetanib therapy was 6.1 (0.1-9.7+)* years with treatment ongoing in 9 patients. Best response was partial response in 10, stable disease in 6, and progressive disease in one patient. Duration of response was 7.4 (0.6-8.7+)* and 4.9 (0.6-7.8+)* years in patients with PR and SD, respectively. Six patients died 2.0 (0.4-5.7)* years after progression. Median progression-free survival (PFS) was 6.7 years [95% confidence interval (CI): 2.3 years-undefined] and 5-year overall survival (OS) was 88.2% (95% CI: 60.6%-96.9%). Of 16 patients with a p.Met918Thr mutation, progression-free survival was 6.7 years (95% CI: 3.1-undefined) and 5-year overall survival was 93.8% (95% CI: 63.2%-99.1%). No patients terminated treatment because of toxicity. DNA sequencing of tissue samples ( = 11) identified an increase in copy number alterations across the genome as a potential mechanism of drug resistance [*median (range)]. This study demonstrates that vandetanib is safe and results in sustained responses in children and adolescents with hereditary MTC. Our preliminary molecular data suggest that an increase in copy number abnormalities may be associated with tumor progression in hereditary MTC patients treated with vandetanib. .
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http://dx.doi.org/10.1158/1078-0432.CCR-17-2101DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5815946PMC
February 2018

SARC006: Phase II Trial of Chemotherapy in Sporadic and Neurofibromatosis Type 1 Associated Chemotherapy-Naive Malignant Peripheral Nerve Sheath Tumors.

Sarcoma 2017 12;2017:8685638. Epub 2017 Sep 12.

Pediatric Oncology Branch, NCI, CCR, Bethesda, MD, USA.

Background: Worse chemotherapy response for neurofibromatosis type 1- (NF1-) associated compared to sporadic malignant peripheral nerve sheath tumors (MPNST) has been reported.

Methods: We evaluated the objective response (OR) rate of patients with AJCC Stage III/IV chemotherapy-naive NF1 MPNST versus sporadic MPNST after 4 cycles of neoadjuvant chemotherapy, 2 cycles of ifosfamide/doxorubicin, and 2 cycles of ifosfamide/etoposide. A Simon optimal two-stage design was used (target response rate 40%).

Results: 34 NF1 (median age 33 years) and 14 sporadic (median age 40 years) MPNST patients enrolled. Five of 28 (17.9%) evaluable NF1 MPNST patients had a partial response (PR), as did 4 of 9 (44.4%) patients with sporadic MPNST. Stable disease (SD) was achieved in 22 NF1 and 4 sporadic MPNST patients. In both strata, results in the initial stages met criteria for expansion of enrollment. Only 1 additional PR was observed in the expanded NF1 stratum. Enrollment was slower than expected and the trial closed before full accrual.

Conclusions: This trial was not powered to detect differences in response rates between NF1 and sporadic MPNST. While the OR rate was lower in NF1 compared to sporadic MPNST, qualitative responses were similar, and disease stabilization was achieved in most patients.
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http://dx.doi.org/10.1155/2017/8685638DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5613633PMC
September 2017

Volumetric MRI Analysis of Plexiform Neurofibromas in Neurofibromatosis Type 1: Comparison of Two Methods.

Acad Radiol 2018 02 31;25(2):144-152. Epub 2017 Oct 31.

Center for Cancer Research, Pediatric Oncology Branch, National Cancer Institute, 10 Center Drive, CRC Room 1-5750, Bethesda, MD 20892. Electronic address:

Objectives: Plexiform neurofibromas (PNs) are complex, histologically benign peripheral nerve sheath tumors that are challenging to measure by simple line measurements. Computer-aided volumetric segmentation of PN has become the recommended method to assess response in clinical trials directed at PN. Different methods for volumetric analysis of PN have been developed. The goal of this study is to test the level of agreement in volume measurements and in interval changes using two separate methods of volumetric magnetic resonance imaging analysis.

Methods: Three independent volume measurements were performed on 15 PN imaged at three time-points using 3DQI software at Massachusetts General Hospital (MGH) and National Cancer Institute (NCI) and MEDx software at NCI.

Results: Median volume differences at each time-point comparing MGH-3DQI and NCI-3DQI were -0.5, -4.2, and -19.9 mL; comparing NCI-3DQI and NCI-MEDx were -21.0, -47.0, and -21.0 mL; comparing MGH-3DQI and NCI-MEDx were -10.0, -70.3, and -29.9 mL. Median differences in percentage change over time comparing MGH-3DQI and NCI-3DQI were -1.7, 1.1, and -1.0%; comparing NCI-3DQI and NCI-MEDx were -2.3, 3.3, and -1.1%; comparing MGH-3DQI and NCI-MEDx were -0.4, 2.0, and -1.5%. Volume differences were <20% of the mean of the two measurements in 117 of 135 comparisons (86.7%). Difference in interval change was <20% in 120 of the 135 comparisons (88.9%), while disease status classification was concordant in 115 of 135 comparisons (85.2%).

Conclusions: The volumes, interval changes, and progression status classifications were in good agreement. The comparison of two volumetric analysis methods suggests no systematic differences in tumor assessment. A prospective comparison of the two methods is planned.
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http://dx.doi.org/10.1016/j.acra.2017.09.004DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5794522PMC
February 2018

Activity of Selumetinib in Neurofibromatosis Type 1-Related Plexiform Neurofibromas.

N Engl J Med 2016 12;375(26):2550-2560

From the Center for Cancer Research, Pediatric Oncology Branch, Bethesda (E.D., A. Baldwin, L.J.M., P. Whitcomb, S.M., R.E., P. Wolters, J.T., J.G., A.J.S., A.G., B.C.W.) and the Cancer Therapy Evaluation Program, Shady Grove (A.L.D.), National Cancer Institute, and the National Heart, Lung, and Blood Institute (A. Brofferio), Bethesda, National Institutes of Health, and the Food and Drug Administration, Silver Spring (L.J.M., R.E.) - all in Maryland; the Division of Oncology, Children's Hospital of Philadelphia, and the Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia (M.J.F., J.B.B.); Children's National Health System, Washington, DC (A.K.); and Cincinnati Children's Hospital, Cincinnati (B.W., L.E.A.-S., T.A.R., J.W., E.S., N.R.).

Background: Effective medical therapies are lacking for the treatment of neurofibromatosis type 1-related plexiform neurofibromas, which are characterized by elevated RAS-mitogen-activated protein kinase (MAPK) signaling.

Methods: We conducted a phase 1 trial of selumetinib (AZD6244 or ARRY-142886), an oral selective inhibitor of MAPK kinase (MEK) 1 and 2, in children who had neurofibromatosis type 1 and inoperable plexiform neurofibromas to determine the maximum tolerated dose and to evaluate plasma pharmacokinetics. Selumetinib was administered twice daily at a dose of 20 to 30 mg per square meter of body-surface area on a continuous dosing schedule (in 28-day cycles). We also tested selumetinib using a mouse model of neurofibromatosis type 1-related neurofibroma. Response to treatment (i.e., an increase or decrease from baseline in the volume of plexiform neurofibromas) was monitored by using volumetric magnetic resonance imaging analysis to measure the change in size of the plexiform neurofibroma.

Results: A total of 24 children (median age, 10.9 years; range, 3.0 to 18.5) with a median tumor volume of 1205 ml (range, 29 to 8744) received selumetinib. Patients were able to receive selumetinib on a long-term basis; the median number of cycles was 30 (range, 6 to 56). The maximum tolerated dose was 25 mg per square meter (approximately 60% of the recommended adult dose). The most common toxic effects associated with selumetinib included acneiform rash, gastrointestinal effects, and asymptomatic creatine kinase elevation. The results of pharmacokinetic evaluations of selumetinib among the children in this trial were similar to those published for adults. Treatment with selumetinib resulted in confirmed partial responses (tumor volume decreases from baseline of ≥20%) in 17 of the 24 children (71%) and decreases from baseline in neurofibroma volume in 12 of 18 mice (67%). Disease progression (tumor volume increase from baseline of ≥20%) has not been observed to date. Anecdotal evidence of decreases in tumor-related pain, disfigurement, and functional impairment was observed.

Conclusions: Our early-phase data suggested that children with neurofibromatosis type 1 and inoperable plexiform neurofibromas benefited from long-term dose-adjusted treatment with selumetinib without having excess toxic effects. (Funded by the National Institutes of Health and others; ClinicalTrials.gov number, NCT01362803 .).
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http://dx.doi.org/10.1056/NEJMoa1605943DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5508592PMC
December 2016

Orbital/Periorbital Plexiform Neurofibromas in Children with Neurofibromatosis Type 1: Multidisciplinary Recommendations for Care.

Ophthalmology 2017 01 3;124(1):123-132. Epub 2016 Nov 3.

Pediatric Oncology Branch, National Cancer Institute, Bethesda, Maryland.

Topic: Children and adults with neurofibromatosis type 1 (NF1), a common autosomal dominant condition, manifest a variety of ophthalmologic conditions. Plexiform neurofibromas (PNs) involving the eyelid, orbit, periorbital, and facial structures (orbital-periorbital plexiform neurofibroma [OPPN]) can result in significant visual loss in children. Equally important, OPPNs can cause significant alteration in physical appearance secondary to proptosis, ptosis, and facial disfigurement, leading to social embarrassment and decreased self-esteem.

Clinical Relevance: Although NF1 is a relatively common disease in which routine ophthalmologic examinations are required, no formal recommendations for clinical care of children with OPPNs exist. Although medical and surgical interventions have been reported, there are no agreed-on criteria for when OPPNs require therapy and which treatment produces the best outcome.

Methods: Because a multidisciplinary team of specialists (oculofacial plastics, pediatric ophthalmology, neuro-ophthalmology, medical genetics, and neuro-oncology) direct management decisions, the absence of a uniform outcome measure that represents visual or aesthetic sequelae complicates the design of evidence-based studies and feasible clinical trials.

Results: In September 2013, a multidisciplinary task force, composed of pediatric practitioners from tertiary care centers experienced in caring for children with OPPN, was convened to address the lack of clinical care guidelines for children with OPPN.

Conclusions: This consensus statement provides recommendations for ophthalmologic monitoring, outlines treatment indications and forthcoming biologic therapy, and discusses challenges to performing clinical trials in this complicated condition.
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http://dx.doi.org/10.1016/j.ophtha.2016.09.020DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5173440PMC
January 2017

Current whole-body MRI applications in the neurofibromatoses: NF1, NF2, and schwannomatosis.

Neurology 2016 Aug;87(7 Suppl 1):S31-9

From The Russell H. Morgan Department of Radiology and Radiological Science (S.A., L.M.F., M.A.J.), Sidney Kimmel Comprehensive Cancer Center (M.A.J.), and Department of Neurology (J.O.B.), Johns Hopkins University, Baltimore, MD; Khyber Medical College (M.S.K.), Peshawar, Pakistan; Department of Radiology (M.A.B., G.J.H., W.C.), Massachusetts General Hospital and Harvard Medical School, Boston; Genomic Medicine (D.G.E.), Manchester Academic Health Science Centre, The University of Manchester, UK; Department of Neurology (S.F., V.F.M.), University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Radiology & Orthopedic Surgery (A.C.), UT Southwestern Medical Center, Dallas, TX; Department of Diagnostic and Interventional Radiology (J.M.S.), University Hospital Hamburg-Eppendorf; Radiological Practice Altona (R.W.), Hamburg, Germany; Pediatric Oncology Branch (E.D.), National Cancer Institute, Bethesda, MD; and Department of Neurology and Cancer Center (S.R.P.), Massachusetts General Hospital, Boston.

Objectives: The Response Evaluation in Neurofibromatosis and Schwannomatosis (REiNS) International Collaboration Whole-Body MRI (WB-MRI) Working Group reviewed the existing literature on WB-MRI, an emerging technology for assessing disease in patients with neurofibromatosis type 1 (NF1), neurofibromatosis type 2 (NF2), and schwannomatosis (SWN), to recommend optimal image acquisition and analysis methods to enable WB-MRI as an endpoint in NF clinical trials.

Methods: A systematic process was used to review all published data about WB-MRI in NF syndromes to assess diagnostic accuracy, feasibility and reproducibility, and data about specific techniques for assessment of tumor burden, characterization of neoplasms, and response to therapy.

Results: WB-MRI at 1.5T or 3.0T is feasible for image acquisition. Short tau inversion recovery (STIR) sequence is used in all investigations to date, suggesting consensus about the utility of this sequence for detection of WB tumor burden in people with NF. There are insufficient data to support a consensus statement about the optimal imaging planes (axial vs coronal) or 2D vs 3D approaches. Functional imaging, although used in some NF studies, has not been systematically applied or evaluated. There are no comparative studies between regional vs WB-MRI or evaluations of WB-MRI reproducibility.

Conclusions: WB-MRI is feasible for identifying tumors using both 1.5T and 3.0T systems. The STIR sequence is a core sequence. Additional investigation is needed to define the optimal approach for volumetric analysis, the reproducibility of WB-MRI in NF, and the diagnostic performance of WB-MRI vs regional MRI.
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http://dx.doi.org/10.1212/WNL.0000000000002929DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5578359PMC
August 2016

Phase II trial of pegylated interferon alfa-2b in young patients with neurofibromatosis type 1 and unresectable plexiform neurofibromas.

Neuro Oncol 2017 02;19(2):289-297

Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA.

Background: There is no proven medical therapy for plexiform neurofibromas (PNs). We undertook a phase II trial of pegylated interferon (PI) to evaluate response and time to progression (TTP).

Methods: PI was administered as a subcutaneous injection to patients with neurofibromatosis type 1‒related PN, stratified by the presence of symptoms (asymptomatic: stratum 1, symptomatic: stratum 2) or documented imaging progression (stratum 3). Patients in strata 1 and 2 received PI for up to one year if stable, 2 years for those with clinical (stratum 2) or imaging response (≥20% decrease in volume). Patients on stratum 3 continued PI until progression. PI was considered active in stratum 3 if TTP doubled compared with the placebo arm of a previous randomized trial using tipifarnib.

Results: Enrolled were 82 evaluable patients (median age 10 y; range 1.6 to 21.4). Fatigue and/or worsening of behavioral issues were the most common toxicities requiring dose modification. Across all strata, imaging responses were seen in 4 patients (5%). Three of 26 symptomatic patients on stratum 2 met the criteria for clinical response without corresponding imaging changes. In stratum 3, median TTP was 29.4 months versus 11.8 for the placebo arm of the previous trial (P=.031). The slope of tumor growth on PI slowed significantly compared with the slope before starting PI (P=.044).

Conclusions: In patients with active PN, PI results in more than doubling of the TTP compared with placebo. Imaging changes in symptomatic patients were not associated with changes in clinical status.
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http://dx.doi.org/10.1093/neuonc/now158DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5464149PMC
February 2017