scholarly journals Efficacy and Biomarker Study of Bevacizumab for Hearing Loss Resulting From Neurofibromatosis Type 2–Associated Vestibular Schwannomas

2016 ◽  
Vol 34 (14) ◽  
pp. 1669-1675 ◽  
Author(s):  
Jaishri O. Blakeley ◽  
Xiaobu Ye ◽  
Dan G. Duda ◽  
Chris F. Halpin ◽  
Amanda L. Bergner ◽  
...  
Keyword(s):  
Vascular Endothelial Growth Factor ◽  
Hearing Loss ◽  
Growth Factor ◽  
Neurofibromatosis Type ◽  
Neurofibromatosis Type 2 ◽  
Vestibular Schwannomas ◽  
Vascular Endothelial ◽  
Bevacizumab Treatment ◽  
Endothelial Growth Factor

Purpose Neurofibromatosis type 2 (NF2) is a tumor predisposition syndrome characterized by bilateral vestibular schwannomas (VSs) resulting in deafness and brainstem compression. This study evaluated efficacy and biomarkers of bevacizumab activity for NF2-associated progressive and symptomatic VSs. Patients and Methods Bevacizumab 7.5 mg/kg was administered every 3 weeks for 46 weeks, followed by 24 weeks of surveillance after treatment with the drug. The primary end point was hearing response defined by word recognition score (WRS). Secondary end points included toxicity, tolerability, imaging response using volumetric magnetic resonance imaging analysis, durability of response, and imaging and blood biomarkers. Results Fourteen patients (estimated to yield > 90% power to detect an alternative response rate of 50% at alpha level of 0.05) with NF2, with a median age of 30 years (range, 14 to 79 years) and progressive hearing loss in the target ear (median baseline WRS, 60%; range 13% to 82%), were enrolled. The primary end point, confirmed hearing response (improvement maintained ≥ 3 months), occurred in five (36%) of 14 patients (95% CI, 13% to 65%; P < .001). Eight (57%) of 14 patients had transient hearing improvement above the 95% CI for WRS. No patients experienced hearing decline. Radiographic response was seen in six (43%) of 14 target VSs. Three grade 3 adverse events, hypertension (n = 2) and immune-mediated thrombocytopenic purpura (n = 1), were possibly related to bevacizumab. Bevacizumab treatment was associated with decreased free vascular endothelial growth factor (not bound to bevacizumab) and increased placental growth factor in plasma. Hearing responses were inversely associated with baseline plasma hepatocyte growth factor (P = .019). Imaging responses were associated with high baseline tumor vessel permeability and elevated blood levels of vascular endothelial growth factor D and stromal cell–derived factor 1α (P = .037 and .025, respectively). Conclusion Bevacizumab treatment resulted in durable hearing response in 36% of patients with NF2 and confirmed progressive VS-associated hearing loss. Imaging and plasma biomarkers showed promising associations with response that should be validated in larger studies.

Bevacizumab treatment for vestibular schwannomas in neurofibromatosis type two: report of two cases, including responses after prior gamma knife and vascular endothelial growth factor inhibition therapy

2011 ◽  
Vol 126 (1) ◽  
pp. 79-82 ◽  
Author(s):  
G K Eminowicz ◽  
R Raman ◽  
J Conibear ◽  
P N Plowman
Keyword(s):  
Vascular Endothelial Growth Factor ◽  
Growth Factor ◽  
Gamma Knife ◽  
Previous History ◽  
Gamma Knife Radiosurgery ◽  
Neurofibromatosis Type ◽  
Vestibular Schwannomas ◽  
Vascular Endothelial ◽  
Bevacizumab Treatment ◽  
Endothelial Growth Factor

AbstractObjectives:Vestibular schwannomas are the hallmark of neurofibromatosis type two. They are difficult to treat, due to their bilateral presentation and the quest for hearing preservation. Our report describes a new treatment approach in this clinical scenario.Case report:We report two cases which confirm that bevacizumab, a monoclonal antibody targeting vascular endothelial growth factor, causes regression of vestibular schwannomas in patients with a previous history of gamma knife radiosurgery or failed treatment with another form of vascular endothelial growth factor targeted therapy.Conclusion:In 2009, Plotkin et al. reported the volumetric response of vestibular schwannomas to bevacizumab treatment, both in untreated patients and in patients previously treated with erlotinib, an epidermal growth factor receptor inhibitor. The presented cases support the use of bevacizumab to treat vestibular schwannomas. Given the extremely slow growth of these tumours, we note the rapidity of volume reduction following bevacizumab therapy.

scholarly journals Multicenter, Prospective, Phase II and Biomarker Study of High-Dose Bevacizumab as Induction Therapy in Patients With Neurofibromatosis Type 2 and Progressive Vestibular Schwannoma

2019 ◽  
Vol 37 (35) ◽  
pp. 3446-3454 ◽  
Author(s):  
Scott R. Plotkin ◽  
Dan G. Duda ◽  
Alona Muzikansky ◽  
Jeffrey Allen ◽  
Jaishri Blakeley ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Growth Factor ◽  
Phase Ii ◽  
Standard Dose ◽  
Neurofibromatosis Type ◽  
Neurofibromatosis Type 2 ◽  
High Dose ◽  
Radiographic Response ◽  
Bevacizumab Treatment

PURPOSE Bevacizumab treatment at 7.5 mg/kg every 3 weeks results in improved hearing in approximately 35%-40% of patients with neurofibromatosis type 2 (NF2) and progressive vestibular schwannomas (VSs). However, the optimal dose is unknown. In this multicenter phase II and biomarker study, we evaluated the efficacy and safety of high-dose bevacizumab in pediatric and adult patients with NF2 with progressive VS. PATIENTS AND METHODS Bevacizumab was given for 6 months at 10 mg/kg every 2 weeks, followed by 18 months at 5 mg/kg every 3 weeks. The primary end point was hearing response defined by word recognition score (WRS) at 6 months. Secondary end points included toxicity, radiographic response, quality of life (QOL), and plasma biomarkers. RESULTS Twenty-two participants with NF2 (median age, 23 years) with progressive hearing loss in the target ear (median baseline WRS, 53%) were enrolled. Nine (41%) of 22 participants achieved a hearing response at 6 months (1 of 7 children and 8 of 15 adults; P = .08). Radiographic response was seen in 7 (32%) of 22 patients with VS at 6 months (7 of 15 adults and 0 of 7 children; P = .05). Common mild to moderate adverse events included hypertension, fatigue, headache, and irregular menstruation. Improvement in NF2-related QOL and reduction in tinnitus-related distress were reported in 30% and 60% of participants, respectively. Paradoxically, high-dose bevacizumab treatment was not associated with a significant decrease in free vascular endothelial growth factor but was associated with increased carbonic anhydrase IX, hepatocyte growth factor, placental growth factor, stromal cell-derived factor 1α, and basic fibroblast growth factor concentrations in plasma. CONCLUSION High-dose bevacizumab seems to be no more effective than standard-dose bevacizumab for treatment of patients with NF2 with hearing loss. In contrast to adults, pediatric participants did not experience tumor shrinkage. However, adult and pediatric participants reported similar improvement in QOL during induction. Novel approaches using bevacizumab should be considered for children with NF2.

scholarly journals NFB-08. PHASE II STUDY OF AXITINIB IN PATIENTS WITH NEUROFIBROMATOSIS TYPE 2 AND PROGRESSIVE VESTIBULAR SCHWANNOMAS

2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii419-iii419
Author(s):  
Sheetal Phadnis ◽  
Mari Hagiwara ◽  
Anna Yaffe ◽  
Carole Mitchell ◽  
Theodore Nicolaides ◽  
...  
Keyword(s):  
Growth Factor ◽  
Phase Ii ◽  
Kinase Inhibitor ◽  
Phase Ii Study ◽  
Growth Factor Receptor ◽  
Neurofibromatosis Type ◽  
Neurofibromatosis Type 2 ◽  
Vestibular Schwannomas ◽  
Volumetric Response

Abstract INTRODUCTION Vascular endothelial growth factor receptor (VEGFR), platelet derived growth factor receptor (PDGFR), and c-KIT represent clinically and/or preclinically validated molecular targets in vestibular schwannomas. We conducted a single institution, prospective, open-label, two-stage phase II study (ClinicalTrials.gov identifier NCT02129647) to estimate the response rate to axitinib, an oral multi-receptor tyrosine kinase inhibitor targeting VEGFR, PDGFR and c-KIT, in neurofibromatosis type 2 (NF2) patients with progressive vestibular schwannomas (VS). METHODS NF2 patients older than 5 years with at least one volumetrically measurable, progressive VS were eligible. The primary endpoint was to estimate the objective volumetric response rates to axitinib. Axitinib was given continuously in 28-day cycles for up to of 12 cycles. Response was assessed every 3 months with MRI using 3-D volumetric tumor analysis and audiograms. Volumetric response and progression were defined as ≥20% decrease or increase in VS volume, respectively. RESULTS Twelve eligible patients (ages: 14–56 years) were enrolled on this study. Seven of twelve patients completed 12 cycles (range: 2 to 12 cycles). We observed two imaging and three hearing responses. Best volumetric response was -53.9% after nine months on axitinib. All patients experienced drug-related toxicities, the most common adverse events were diarrhea, hematuria and skin toxicity, not exceeding grade 2 and hypertension, not exceeding grade 3. CONCLUSIONS While axitinib has modest anti-tumor activity in NF2 patients, it is more toxic and appears to be less effective compared to bevacizumab. Based on these findings, further clinical development of axitinib for this indication does not appear warranted.

scholarly journals Relationship between Serum Vascular Endothelial Growth Factor Levels and Stages of Diabetic Retinopathy and Other Biomarkers

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Nakhleh E. Abu-Yaghi ◽  
Nafez M. Abu Tarboush ◽  
Ala M. Abojaradeh ◽  
Amal S. Al-Akily ◽  
Esra’a M. Abdo ◽  
...  
Keyword(s):  
Vascular Endothelial Growth Factor ◽  
Diabetic Retinopathy ◽  
Growth Factor ◽  
Glycosylated Hemoglobin ◽  
Density Lipoprotein ◽  
Significant Negative Correlation ◽  
Vascular Endothelial ◽  
Endothelial Growth Factor ◽  
Dm Type 2

Aim. This study aims to measure serum vascular endothelial growth factor (VEGF) levels in a sample of Jordanian patients and to determine their relationship with the different stages of diabetic retinopathy. It also explores the correlation between VEGF concentrations and different biochemical and demographic findings. Materials and Methods. A total of 167 adults participated in the study. Participants were divided into two main categories: patients with diabetes mellitus (DM) type 2 without diabetic retinopathy (DR) (N = 62) and patients with DM type 2 affected by DR (N = 105). DR patients were further subclassified into nonproliferative (N = 41) and proliferative (N = 64). Basic laboratory tests were measured to correlate with VEGF levels. Irisin, a hormone linked to diabetic retinopathy was also measured and correlated with VEGF. Results. Serum VEGF was found to positively correlate with the severity of diabetic retinopathy. The means of VEGF serum concentrations were 60 pg/mL for controls, 133 pg/mL for nonproliferative DR patients, and 229 pg/mL for proliferative DR patients. We found a significant positive correlation with glycosylated hemoglobin (HbA1c), and a significant negative correlation with high-density lipoprotein (HDL) levels, age, and irisin. Conclusion. In this cohort of Jordanian diabetics, serum VEGF concentrations strongly correlated with the presence and stages of diabetic retinopathy, suggesting it as an appropriate indicator for diabetic retinopathy early detection and management in this society. VEGF levels also significantly correlated with HbA1c, HDL, and irisin levels. Further studies are encouraged to explore these relationships in other ethnic groups and with different diabetic complications.

scholarly journals The type 2 vascular endothelial growth factor receptor recruits insulin receptor substrate-1 in its signalling pathway

2002 ◽  
Vol 368 (1) ◽  
pp. 49-56 ◽  
Author(s):  
Duraisamy SENTHIL ◽  
Goutam GHOSH CHOUDHURY ◽  
Basant K. BHANDARI ◽  
Balakuntalam S. KASINATH
Keyword(s):  
Vascular Endothelial Growth Factor ◽  
Protein Synthesis ◽  
Growth Factor ◽  
Epithelial Cells ◽  
Tyrosine Phosphorylation ◽  
Kinase Activity ◽  
Insulin Receptor Substrate ◽  
Vascular Endothelial ◽  
Endothelial Growth Factor

Vascular endothelial growth factor (VEGF) isoforms exert their biological effects through receptors that possess intrinsic tyrosine kinase activity. Whether VEGF binding to its receptors recruits insulin receptor substrate (IRS) family of docking proteins to the receptor is not known. Following incubation of mouse kidney proximal tubular epithelial cells with VEGF, we observed an increase in tyrosine phosphorylation of several proteins, including one of 200kDa, suggesting possible regulation of phosphorylation of IRS proteins. VEGF augmented tyrosine phosphorylation of IRS-1 in kidney epithelial cells and rat heart endothelial cells in a time-dependent manner. In the epithelial cells, association of IRS-1 with type 2 VEGF receptor was promoted by VEGF. VEGF also increased association of IRS-1 with the p85 regulatory subunit of phosphoinositide 3-kinase (PI 3-kinase), and PI 3-kinase activity in IRS-1 immunoprecipitates was increased in VEGF-treated cells. Incubation of epithelial cells with antisense IRS-1 oligonucleotide, but not sense oligonucleotide, reduced expression of the protein and VEGF-induced PI 3-kinase activity in IRS-1 immunoprecipitates. Additionally, VEGF-induced protein synthesis was also impaired by antisense but not sense IRS-1 oligonucleotide. These data provide the first evidence that binding of VEGF to its type 2 receptor promotes association of IRS-1 with the receptor complex. This association may account for some of the increase in VEGF-induced PI 3-kinase activity, and the increase in de novo protein synthesis seen in renal epithelial cells.

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