Loading

Bevacizumab: A Review of Use in High Grade Gliomas

Review Article | Open Access | Volume 4 | Issue 4

  • 1. Department of Neurology, Geisinger Medical Center, USA
+ Show More - Show Less
Corresponding Authors
Scott G. Turner, Department of Neurology, Geisinger Medical Center, 100 North Academy Ave., Danville, PA 17822, USA Tel: 570-271-6590; Fax: 570-271-6663
Abstract

Malignant gliomas are the most common type of primary malignant brain tumors in adults. They have a grave prognosis that is attributed to their high proliferative index and increased vascular proliferation. The latter is primarily mediated by the secretion of Vascular Endothelial Growth Factor (VEGF) by tumor cells, which leads to the development of an increased number of abnormal blood vessels in and around the tumor. There has been evidence of radiographic response with clinical improvement by targeting this signaling pathway using VEGF/VEGF receptor inhibitors, primarily bevacizumab (BEV), a monoclonal antibody against VEGF, which has been approved by the Food and Drug Administration (FDA) for treatment of recurrent gliomas. Though it extends progression-free survival (PFS) and decreases the reliance on steroids, BEV has not been shown to confer a survival benefit in patients with malignant glioma. We have reviewed the available literature to demonstrate the effectiveness and drawbacks of BEV therapy reinforcing the need for research into newer, better-tolerated and more effective modalities.

Keywords

•    Glioma
•    VEGF
•    Angiogenesis
•    Bevacizumab
•    Temozolomide

Citation

Kala N, Turner SG (2017) Bevacizumab: A Review of Use in High Grade Gliomas. J Drug Des Res 4(4): 1046.

ABBREVIATIONS

VEGF: Vascular Endothelial Growth Factor; BEV: Bevacizumab; FDA: Food and Drug Administration; PFS: Progression-Free Survival; GBM: Glioblastoma Multiforme; RT: Radiotherapy; TMZ: Temozolomide; OS: Overall Survival; HIF: HypoxiaInducible Factor; MAPK: Mitogen-Activated Protein Kinase; PI3K: Phosphoinositide 3-Kinase; FGF: Fibroblast Growth Factor (FGF); PDGF: Platelet-Derived Growth Factor; MRI: Magnetic Resonance Imaging; IRI: Irinotectan (IRI); MGMT: O-6-MethylguanineDNA Methyltransferase; PD-1: Programmed Cell Death-1; PET: Positron Emission Tomography; HGF: Hepatocyte Growth Factor; TGF: Transforming Growth Factor; Ang: ΑνγIopoietin; PTP1B: Protein Tyrosine Phosphatase 1B

INTRODUCTION

Gliomas are classified into low grade (grades I and II) and high grade (grades III and IV) [1]. Grade IV (glioblastoma multiforme/ GBM) is the most aggressive type with the poorest prognosis and is characterized by high mitotic activity, hypoxia and necrosis, cellular polymorphism and microvascular proliferation [2]. The current standard of care for high-grade glioma is maximal safe resection followed by radiotherapy (RT) and temozolomide (TMZ) chemotherapy, followed by TMZ monotherapy, the socalled Stupp protocol [3]. This combination affords an overall survival (OS) and progression free survival (PFS) of 14.7 months and 6.9 months respectively [3].

The mechanism of microvascular proliferation and angiogenesis in gliomas appears to be driven by both hypoxiadependent (mediated by hypoxia-inducible factor (HIF)-1α) [4] and -independent (via the Mitogen-activated protein kinases (MAPKs) and Phosphoinositide 3-kinase (PI3K) pathways) [5] mechanisms mediated by pro-angiogenic factors like VEGF, fibroblast growth factor (FGF), and platelet-derived growth factor (PDGF) [6]. VEGF appears to be the one of the most important proangiogenic factors whose level of expression is higher in areas of hypoxia and correlates with tumor grade [7]. The VEGF gene includes six subtypes (VEGF-A, B, C, D, E and placental growth factor PIGF), of which VEGF-A has been best characterized and is known to be associated with higher glioma grades and poorer prognosis [6,8]. New tumor vasculature, however, is both structurally and functionally abnormal [9] leading to leakage of fluid with resultant edema and gadolinium enhancement on magnetic resonance imaging (MRI). Bevacizumab (BEV) is a monoclonal antibody composed 93% of human IgG1 and 7% VEGF complementarity-determining regions, which binds the six forms of VEGF [10]. By binding VEGF, BEV directly inhibits neovascularization and thereby plays a role in the decrease in tumor size and growth. Angiogenesis is critically important in the growth of high-grade glioma, and offers many therapeutic targets for therapy. Our goal in this review is to describe the potential risks and benefits of BEV in the treatment of primary or recurrent high-grade gliomas.

Recurrent GBM

The FDA approval of BEV with irinotectan (IRI) in colorectal cancer prompted two single-arm Phase II prospective studies for their use in patients with malignant gliomas who had recurred after receiving standard therapy with RT and Temozolomide. The BRAIN trial was designed with two cohorts of 35 patients with known GBM and prior treatment with standard therapy, the initial cohort of 23 patients receiving both BEV and IRI every 14 days. Once this was deemed safe, a second cohort of 12 patients was treated with IRI for 4 doses in 6 weeks and BEV every 3 weeks [11]. The results seemed promising with a 6 month PFS of 46% (95%CI 32-66%) and median PFS of 24 weeks (95%CI 18-36 weeks) with no statistical difference between the cohorts. The 6-month OS was 77% (95%CI 64-92%) and median OS of 42 weeks (95%CI 35-60 weeks). Twenty patients (57%) had at least partial response and six of them showed no residual high-grade tumor after 1 year. However, there were quite a few complications including thromboembolism (4), grade 2-3 proteinuria (2), sepsis (1) and intracranial hemorrhage (1). Thirteen patients went on to have progression of the disease and four patients dropped out voluntarily citing fatigue as the major side effect.

A second study involved a cohort of 32 patients with recurrent glioma (23 Grade IV and 9 Grade III) treated with BEV and IRI [12]. This regimen demonstrated 63% radiographic response (20 patients; 14 Grade IV and 6 Grade III) and a PFS period of 23 weeks (95%CI 15-30 weeks). The 6-month PFS was 38% (95%CI 24-59%) for the whole group with a 6-month OS of 72% (95%CI 58-89%). These results were better than other anti-angiogenic therapies like thalidomide (which weakly inhibits VEGF and FGF) which demonstrated a 6% response and median PFS of 10 weeks [13]. The complications, however, were significant with thromboembolism (3), ischemic stroke (1), and proteinuria (2); including two deaths in the patients with stroke and pulmonary embolus. Twelve patients had progression of disease and two dropped out due to fatigue.

With improvement in PFS and an acceptable side effect profile at a moderate efficacy, BEV was FDA approved for use as a combination with IRI or alone in recurrent high-grade glioma 2009. Subsequently, the BELOB trial investigated the use of BEV with or without Lomustine in patients with a first recurrence of GBM. Using Response Assessment in Neuro-Oncology Criteria (RANO), an improvement in 9 month OS (38% BEV alone, 43% lomustine alone, vs. 59% for combination therapy) was seen [14]. The EORTC-2601 trial, on the other hand, compared lomustine monotherapy to BEV plus lomustine combination therapy and though PFS was improved (4.2 months vs. 1.5 months), no significant difference in OS (9.1 months vs. 8.6 months) was noted [15].

Newly Diagnosed GBM

There was a hope that BEV could be an important drug in the treatment of gliomas and this lead to trials investigating BEV as first line therapy with TMZ. In a single-arm, multicenter Phase II trial of combined RT, TMZ and BEV in 70 patients with newly diagnosed glioblastoma, patients received concurrent administration of daily TMZ and biweekly BEV with RT followed by TMZ for 5 days every 4 weeks and continued biweekly BEV [16]. The control group received RT/TMZ followed by TMZ for 5 days every 4 weeks and BEV at recurrence. The study group showed improved PFS (13.6 months vs. 7.6 months) without improved OS (19.6 months vs. 21.1 months). The groups showed expected post RT adverse effects including neutropenia, fatigue, venous thrombosis, hypertension and proteinuria. However, the group receiving BEV showed increased incidence of cerebrovascular ischemia, wound infections, GI perforations, GI bleeds, and CNS hemorrhage. The higher risk of ischemia was observed with a pattern suggestive of involvement of small vessels, including lenticulostriate perforating arteries and potentiation of radiationinduced occlusive arteriopathy.

The RTOG 0825 study was a large randomized, placebocontrolled, double-blinded trial of 637 patients in which patients (following radiotherapy and daily TMZ) received BEV or placebo from week 4 of RT continued for 12 weeks [17]. There was no significant overall survival benefit of adding BEV (15.7 months vs. 16.1 months respectively, hazard ratio (HR) 1.13) though PFS was slightly improved (10.7 months vs. 7.3 months, HR 0.79). The treatment effects after adjustment for O-6-methylguanine-DNA methyltransferase (MGMT) resistance status were unchanged and statistically insignificant. Serious adverse effects were more prevalent in the BEV group and included hypertension (4.2 vs. 0.9%), thromboembolism (7.7 vs. 4.7%), wound dehiscence (1.5 vs. 0.9%), visceral perforation (1.2 vs. 0.4%), serious hemorrhage (1.5 vs. 0.9%) and serious neutropenia (10.0 vs. 5.1%). In addition, patients who had progression in the BEV group reported poorer quality of life and worse neuro-cognitive decline.

The AVAglio study likewise compared BEV to placebo in combination with standard radiation and temozolomide chemotherapy. Again, PFS was improved (10.6 months vs. 6.2 months) but no improvement in overall survival (16.8 months vs. 16.7 months). BEV did, however, appear to decrease dependence on steroids and prolong cognitive function in this study [18-26].

Immunotherapy

Recently tumor immunity is also thought to play a significant role with studies suggesting that anti-angiogenic factors increase delivery of tumor effector cells into the tumor [27]. There are suggestions that combination immunotherapy can play a key role in resistance to anti-angiogenic therapy as well. This has opened new avenues to the research in the use of immunomodulators in new diagnosis of GBM. Immune checkpoint inhibitors have been FDA approved for use in melanoma and lung cancer and this has led to a trial of anti-PD-L1 antibody with standard radiotherapy in newly diagnosed GBM (NCT02336165) and CheckMate143 (NCT02017717) evaluating the safety and efficacy of AntiPD-1 (Programmed Cell Death-1) antibody vs. BEV in recurrent gliomas. Dendritic cell vaccines and peptide vaccines are also under investigation. In a phase II trial testing standard therapy with dendritic cell vaccine (AV0113) [28], there is report that a subgroup receiving the vaccine as a second line to BEV showed improved OS compared to the control group (535 ± 155 days vs 406 ± 224 days), while there was no difference reported in patients receiving only standard therapy without BEV. Similar reports from another phase II trial with use of peptide vaccine (rindopepimut against EGFRvIII) where there was prolonged median OS (12 mo. vs. 8.8 mo., HR 0.47) and improved 6-month PFS (26% vs. 11%) [29]. Additional trials are underway looking at heat shock protein vaccines, Wilms tumor protein vaccines and engineered T cells use [30]. Oncolytic viral therapy is a novel approach and offers quite some advantages with lack of cross-reactivity with chemo, synergism, immune response [31], and several oncolytic viruses are currently being tested.

Pseudoprogression

An inflammatory reaction known as “pseudoprogression” can occur weeks to months following chemo-radiation in which MRI shows increased enhancement and edema that mimics true progression [32]. This may progress to radiation-induced necrosis which also mimics recurrent tumor on imaging. MGMT promoter methylation increases the probability of pseudoprogression [33] but there is no reliable biomarker study to differentiate tumor progression from pseudoprogression. Distinguishing pseudoprogression from true tumor progression remains a challenge in neuro-oncology and, though magnetic resonance spectroscopy, magnetic resonance perfusion, and Positron Emission Tomography (PET) scans have all been employed to diagnose pseudoprogression, none has a sensitivity of greater than 70-80% [34]. The use of BEV may also act as a confounding factor in such a diagnosis due its pseudoresponse. Differentiating between tumor progression and pseudoprogression has important clinical implications as each is managed very differently: pseudoprogression might require temporary cessation of chemo-radiation while tumor progresion requires continued therapy.

There is no consensus for treatment of pseudoprogression, though corticosteroids, anticoagulation, and hyperbaric oxygen have all been advocated. Surgery remains an option in symptomatic patients with radiation necrosis and surgery not only provides a tissue diagnosis but also reduces mass effect and edema. BEV has been shown to reduce contrast enhancement and improve T2/FLAIR sequences on MRI in patients with demonstrated radiation necrosis and reduce reliance on corticosteroids [35]. Its use has been advocated in symptomatic patients based on the results of a randomized double blind placebo controlled trial [36] and patients with recurrent radiation necrosis may respond to repeated BEV therapy [37].

Bevacizumab resistance

Though it affords improved PFS, BEV does not provide a survival benefit for patients with malignant glioma. There are several possible reasons for resistance to BEV. Besides VEGF, other molecules are known to be involved in neovascularization, including FGF, hepatocyte growth factor (HGF), PDGF, transforming growth factor (TGF)-α, ενδογλιν, ανδ Ανγiopoietin (Ang)−2 [38]. Εffεχτιϖελψ blocking angiogenesis would therefore require inhibiting multiple pathways and there are studies underway looking at blocking VEGF with BEV along with Ang-2 [39], integrins [40], and endoglin [41]. In addition to redundant angiogenic pathways, tumors employ other mechanisms to satisfy their metabolic needs including the poorly understood mechanism of co-option of normal blood vessels, and the differentiation of tumor stem cells into an endothelial phenotype.

A perhaps more clinically significant consequence of VEGF inhibition is the transformation of glioma cells from a proliferative to a migratory phenotype, a process seen by BEV treatment in other cancers, as well [42]. By inducing a hypoxic environment by inhibiting angiogenesis, BEV therapy leads to upregulation of hypoxia-inducible factors [43] and a transition to a more invasive, mesenchymal phenotype. Glioma cell lines with resistance to BEV show increased expression of mesenchymal markers and increased invasion in vitro [44]. Furthermore, tumors isolated from patients resistant to BEV likewise show upregulation of hypoxia and mesenchymal markers [45]. Microarray analysis of BEV-resistant GBM showed increased expression of the receptor tyrosine kinase, c-Met, which activates various intracellular pathways that promote angiogenesis, cell growth and invasion via HGF-dependent signaling [46]. VEGFR-2 forms a heterodimeric complex with c-Met. Binding of VEGF, recruits protein tyrosine phosphatase 1B (PTP1B), which dephosphorylates and inactivates c-Met, thus suppressing HGF-mediated growth and invasion. C-Met is also expressed on endothelial cells and HGF signaling may represent a non-VEGF dependent pro-angiogenic signaling cascade [47].

Future directions

BEV has improved PFS in patients with malignant glioma when used in conjunction with surgery, radiation- and temozolomide chemotherapy. Angiogenesis is a complex process, offering many potential targets for therapy, and several trials are currently underway to maximize antiangiogenic therapy by combining BEV with other agents. Many small molecule tyrosine kinase inhibitors have been investigated without much success and a study is currently underway using an agent (buparlisib) which targets the PI3K pathway known to be involved in both angiogenesis and invasion (NCT01339052). Trebananib, an ihnibitor of the angiopoietin/Tie-2 signaling pathway is being investigated in combination with BEV (NCT01609790), and an antibody targeting endoglin, an accessory receptor for transforming growth factor (TGF)-β involved in tumor-mediated angiogenesis, has been combined with BEV as well (NCT01648348). In an attempt to induce apoptosis in endothelial cells, a Fas-expressing transgenic adenovirus, VB-111, has been developed for use with BEV in patients with recurrent GBM (NCT02511405) with encouraging overall survival benefit. Because c-Met appears to be a key player in mediating BEV resistance, it makes an especially attractive target for therapy in patients. INC280 is a small molecule Met inhibitor that has been shown to reduce migration and adhesion in ovarian cancer cell models and is currently under investigation in combination with BEV for recurrent glioma (NCT02386826). Onartuzumab, a monoclonal antibody directed against cMet, was combined with BEV (NCT01632228), though it showed no improvement in PFS or overall survival [48]. Finally, an upcoming trial will determine the benefit of combining BEV with Optune Tumor Treating Fields in BEV-refractory recurrent GBM (NCT02743078).

CONCLUSIONS

High-grade gliomas are the most aggressive brain malignancies with a poor prognosis and near universal fatality despite treatment with surgery, radiation- and chemotherapy. The standard of treatment with surgery followed by combination chemo-radiotherapy seems to have a fair overall survival and progression free survival. Targeting angiogenesis with agents like BEV makes good clinical sense and affords a definite radiographic response, but the degree to which this corresponds to clinical improvement is open to debate. In addition to its implication in vasculopathy and possible neurotoxicity, there is also growing concern that BEV could play a role in transition of the proliferative to migratory phenotype in glioma cells thereby promoting tumor infiltration. BEV has not shown significant improvement of overall survival when used as a first line agent and there is a need for better understanding of the resistance to VEGF/VEGF-R antagonists. Targeting several pathways or combination chemotherapy with BEV and other agents such as immunomodulators may help overcome resistance and to maximize benefit. Additional studies are therefore warranted for other newer agents to be used on a large scale.

ACKNOWLEDGEMENTS

We would like to thank Dr. Maleeha Ahmad, Lynn Belles RN, MSN, CNRN, and Jacob Wagner, BA. for their help in reviewing this manuscript

REFERENCES

1. KERNOHAN JW, MABON RF. A simplified classification of the gliomas. Proc Staff Meet Mayo Clin. 1949; 24: 71-75.

2. Louis DN. Molecular pathology of malignant gliomas. Annu Rev Pathol. 2006; 1: 97-117.

3. Stupp R, Mason WP, van den Bent MJ, Weller M, Fisher B, Taphoorn MJ, et al. Radiotherapy plus concomitant and adjuvant temozolomide for glioblastoma. N Engl J Med. 2005; 352: 987-996.

4. Kaur B1, Khwaja FW, Severson EA, Matheny SL, Brat DJ, Van Meir EG. Hypoxia and the hypoxia-inducible-factor pathway in glioma growth and angiogenesis. Neuro Oncol. 2005; 7: 134-153.

5. Maity A, Pore N, Lee J, Solomon D, O’Rourke DM. Epidermal growth factor receptor transcriptionally up-regulates vascular endothelial growth factor expression in human glioblastoma cells via a pathway involving phosphatidylinositol 3’-kinase and distinct from that induced by hypoxia. Cancer Res. 2000; 60: 5879-5886.

6. Schmidt NO, Westphal M, Hagel C, Ergün S, Stavrou D, Rosen EM, et al. Levels of vascular endothelial growth factor, hepatocyte growth factor/scatter factor and basic fibroblast growth factor in human gliomas and their relation to angiogenesis. Int J Cancer. 1999; 84: 10- 18.

7. Huang H, Held-Feindt J, Buhl R, Mehdorn HM, Mentlein R. Expression of VEGF and its receptors in different brain tumors. Neurol Res. 2005; 27: 371-377.

8. Zhou YH, Tan F, Hess KR, Yung WK. The expression of PAX6, PTEN, vascular endothelial growth factor, and epidermal growth factor receptor in gliomas: relationship to tumor grade and survival. Clin Cancer Res. 2003; 9: 3369-3375.

9. Carmeliet P, Jain RK. Angiogenesis in cancer and other diseases. Nature. 2000; 407: 249-257.

10. Ferrara N, Hillan KJ, Gerber HP, Novotny W. Discovery and development of bevacizumab, an anti-VEGF antibody for treating cancer. Nat Rev Drug Discov. 2004; 3: 391-400.

11. Vredenburgh JJ, Desjardins A, Herndon JE 2nd, Marcello J, Reardon DA, Quinn JA, et al. Bevacizumab plus irinotecan in recurrent glioblastoma multiforme. J Clin Oncol. 2007; 25: 4722-4729.

12. Vredenburgh JJ, Desjardins A, Herndon JE 2nd, Dowell JM, Reardon DA, Quinn JA , et al. Phase II trial of bevacizumab and irinotecan in recurrent malignant glioma. Clin Cancer Res. 2007; 13: 1253-1259.

13. Fine HA, Figg WD, Jaeckle K, Wen PY, Kyritsis AP, Loeffler JS, et al. Phase II trial of the antiangiogenic agent thalidomide in patients with recurrent high-grade gliomas. J Clin Oncol. 2000; 18: 708-715.

14. Taal W, Oosterkamp HM, Walenkamp AME, Dubbink HJ, Beerepoot LV, Hanse M, et al. Final Analysis of the BELOB Trial (A Randomized Phase II Study on Bevacizumab versus Bevacizumab plus Lomustine Single Agent in Recurrent Glioblastoma. Neuro-Oncology. 2014; 16: v20-v21.

15. Wick W, Brandes AA, Gorlia T, Bendszus M, Sahm F, Taal W, et al. EORTC 26101 phase III trial exploring the combination of bevacizumab and lomustine in patients with first progression of a glioblastoma. J Clin Oncol. 2016; 34.

16. Lai A, Tran A, Nghiemphu PL, Pope WB, Solis OE, Selch M, et al. Phase II study of bevacizumab plus Temozolomide during and after radiation therapy for patients with newly diagnosed glioblastoma multiforme. J Clin Oncol. 2011; 29: 142-148.

17. Gilbert MR, Dignam JJ, Armstrong TS, Wefel JS, Blumenthal DT, Vogelbaum MA, et al. A randomized trial of bevacizumab for newly diagnosed glioblastoma. N Engl J Med. 2014; 370: 699-708.

18. Cinot OL, Wick W, Mason W, Henriksson R, Saran F, Nishikawa R, et al. Bevacizumab plus Radiotherapy-Temozolomide for Newly Diagnosed Glioblastoma. N Engl J Med. 2014; 370: 709-722.

19. Weis SM, Cheresh DA. Pathophysiological consequences of VEGFinduced vascular permeability. Nature. 2005; 437: 497-504.

20. Willett CG, Boucher Y, di Tomaso E, Duda DG, Munn LL, Tong RT, et al. Direct evidence that the VEGF-specific antibody bevacizumab has antivascular effects in human rectal cancer. Nat Med. 2004; 10: 145- 147.

21. Jain RK. Antiangiogenesis strategies revisited: from starving tumors to alleviating hypoxia. Cancer Cell. 2014; 26: 605-622.

22. Ellingson BM, Cloughesy TF, Lai A, Nghiemphu PL, Mischel PS, Pope WB. Quantitative volumetric analysis of conventional MRI response in recurrent glioblastoma treated with bevacizumab. Neuro Oncol. 2011; 13: 401-409.

23. Gorila ST, Stupp R, Brandes AA, Rampling RR, Fumoleau P, Dittrich C, et al. New prognostic factors and calculators for outcome prediction in patients with recurrent glioblastoma: A pooled analysis of EORTC Brain Tumor Group phase I and II clinical trials. Eur J Cancer. 2012; 48: 1176-1184.

24. Tong RT, Boucher Y, Kozin SV, Winkler F, Hicklin DJ, Jain RK. Vascular normalization by vascular endothelial growth factor receptor 2 blockade induces a pressure gradient across the vasculature and improves drug penetration in tumors. Cancer Res. 2004; 64: 3731- 3736.

25. Rini BI, Garcia JA, Cooney MM, Elson P, Tyler A, Beatty K, et al. Toxicity of sunitinib plus bevacizumab in renal cell carcinoma. J Clin Oncol. 2010; 28: e284-5; author reply e286-287.

26. Mackenzie F, Ruhrberg C. Diverse roles for VEGF-A in the nervous system. Development. 2012; 139: 1371-1380.

27. Huang Y, Goel S, Duda DD, Fukumura D, Jain RK. Vascular normalization as an emergent strategy in to enhance cancer immunotherapy. Cancer Res. 2013; 73: 2943-2948.

28. Buchroithner J, Pichler J, Marosi C, Widhalm G, Seiz-Rosenhagen M, Novosielski M, et al. Vascular endothelial growth factor targeted therapy may improve effect of dendritic cell based cancer immune therapy. Int J Clin Pharmacol Ther. 2013; 52: 76-77.

29. Reardon DA, Schuster J, Tran DD, Fink KL, Nabors LB, Li G, et al. ReACT: Overall Survival From a Randomized Phase II Study of Rindopepimut (CDX-110) Plus Bevacizumab in Relapsed Glioblastoma. Neurosurgery. 62: 198-199.

30. Domingo-Musibay E, Galanis E. What next for newly diagnosed glioblastoma? Future Oncol. 2015; 11: 3273-3283.

31. Lichty BD, Breitbach CJ, Stojdl DF, Bell JC. Going viral with cancer immunotherapy. Nat Rev Cancer. 2014; 14: 559-567.

32. Taal W, Brandsma D, de Bruin HG, Bromberg JE, Swaak-Kragten AT, Smitt PA, et al. Incidence of early pseudo-progression in a cohort of malignant glioma patients treated with chemoirradiation with temozolomide. Cancer. 2008; 113: 405-410.

33. Brandes AA, Franceschi E, Tosoni A, Blatt V, Pession A, Tallini G, et al. MGMT promoter methylation status can predict the incidence and outcome of pseudoprogression after concomitant radiochemotherapy in newly diagnosed glioblastoma patients. J Clin Oncol. 2008; 26: 2192-2197.

34. O’Brien BJ, Colen RR. Post-treatment imaging changes in primary brain tumors. Curr Oncol Rep. 2014; 16: 397.

35. Gonzalez J, Kumar AJ, Conrad CA, Levin VA. Effect of bevacizumab on radiation necrosis of the brain. Int J Radiat Oncol Biol Phys. 2007; 67: 323-326.

36. Levin VA, Bidaut L, Hou P, Kumar AJ, Wefel JS, Bekele BN, et al. Randomized double-blind placebo-controlled trial of bevacizumab therapy for radiation necrosis of the central nervous system. Int J Radiat Oncol Biol Phys. 2011; 79: 1487-1495.

37. Furuse M, Kawabata S, Kuroiwa T, Miyatake S. Repeated treatments with bevacizumab for recurrent radiation necrosis in patients with malignant brain tumors: a report of 2 cases. J Neurooncol. 2011; 102: 471-475.

38. Oltrock, ZK, Mahfouz RA, Makarem JA, Shamseddine AI. Understanding the biology of angiogenesis: Review of the most important molecular mechanisms. Blood Cells Mol Dis. 2007; 39: 212-220.

39. Kienast Y, Klein C, Scheuer W, Raemsch R, Lorenzon E, Bernicke D, et al. Ang-2-VEGF-A CrossMab, a novel bispecific human IgG1 antibody blocking VEGF-A and Ang-2 functions simultaneously, mediates potent antitumor, antiangiogenic, and antimetastatic efficacy. Clin Cancer Res. 2013; 19: 6730-6740.

40. Ishida, J, Onishi M, Kurozumi K, Ichikawa T, Fujii K, Shimazu Y, et al. Integrin Inhibitor Suppresses Bevacizumab-Induced Glioma Invasion. Transl Oncol. 2014; 7: 292-302. 41.Afshar Moghaddam N, Mahsuni P, Taheri D. Evaluation of Endoglin as an Angiogenesis Marker in Glioblastoma. Iran J Pathol. 2015; 10: 89- 96.

42. Fan F, Samuel S, Gaur P, Lu J, Dallas NA, Xia L, et al. Chronic exposure of colorectal cancer cells to bevacizumab promotes compensatory pathways that mediate tumour cell migration. Br J Cancer. 2011; 104: 1270-1277.

43. Blagosklonny MV. Antiangiogenic therapy and tumor progression. Cancer Cell. 2004; 5: 13-17.

44. Piao Y, Liang J, Holmes L, Henry V, Sulman E, de Groot JF. Acquired resistance to anti-VEGF therapy in glioblastoma is associated with a mesenchymal transition. Clin Cancer Res. 2013; 19: 4392-4403.

45. Xu H, Rahimpour S, Nesvick CL, Zhang X, Ma J, Zhang M, et al. Activation of hypoxia signaling induces phenotypic transformation of glioma cells: implications for bevacizumab antiangiogenic therapy. Oncotarget. 2015; 6: 11882-11893.

46. Jahangiri A, DeLay M, Miller LM, Carbonell WS, Hu Y-L, Lu K, et al. Gene expression profile identifies tyrosine kinase c-Met as a targetable mediator of anti-angiogenic therapy resistance. Clin Cancer Res. 2013; 19: 1773-1783.

47. Lu KV, Chang JP, Parachoniak CA, Pandika MM, Aghi MK, Meyronet D, et al. VEGF inhibits tumor cell invasion and mesenchymal transition through a MET/VEGFR2 complex. Cancer Cell. 2012; 22: 21-35.

48. Cloughesy TF, Finocchiaro G, Belda-Iniesta C, Recht L, Brandes AA, Pineda E, et al. Randomized, Double-Blind, Placebo-Controlled, Multicenter Phase II Study of Onartuzumab Plus Bevacizumab Versus Placebo Plus Bevacizumab in Patients With Recurrent Glioblastoma: Efficacy, Safety, and Hepatocyte Growth Factor and O6-Methylguanine-DNA Methyltransferase Biomarker Analyses. J Clin Oncol. 2017; 35: 343-351.

Kala N, Turner SG (2017) Bevacizumab: A Review of Use in High Grade Gliomas. J Drug Des Res 4(4): 1046

Received : 13 Mar 2017
Accepted : 20 Apr 2017
Published : 21 Apr 2017
Journals
Annals of Otolaryngology and Rhinology
ISSN : 2379-948X
Launched : 2014
JSM Schizophrenia
Launched : 2016
Journal of Nausea
Launched : 2020
JSM Internal Medicine
Launched : 2016
JSM Hepatitis
Launched : 2016
JSM Oro Facial Surgeries
ISSN : 2578-3211
Launched : 2016
Journal of Human Nutrition and Food Science
ISSN : 2333-6706
Launched : 2013
JSM Regenerative Medicine and Bioengineering
ISSN : 2379-0490
Launched : 2013
JSM Spine
ISSN : 2578-3181
Launched : 2016
Archives of Palliative Care
ISSN : 2573-1165
Launched : 2016
JSM Nutritional Disorders
ISSN : 2578-3203
Launched : 2017
Annals of Neurodegenerative Disorders
ISSN : 2476-2032
Launched : 2016
Journal of Fever
ISSN : 2641-7782
Launched : 2017
JSM Bone Marrow Research
ISSN : 2578-3351
Launched : 2016
JSM Mathematics and Statistics
ISSN : 2578-3173
Launched : 2014
Journal of Autoimmunity and Research
ISSN : 2573-1173
Launched : 2014
JSM Arthritis
ISSN : 2475-9155
Launched : 2016
JSM Head and Neck Cancer-Cases and Reviews
ISSN : 2573-1610
Launched : 2016
JSM General Surgery Cases and Images
ISSN : 2573-1564
Launched : 2016
JSM Anatomy and Physiology
ISSN : 2573-1262
Launched : 2016
JSM Dental Surgery
ISSN : 2573-1548
Launched : 2016
Annals of Emergency Surgery
ISSN : 2573-1017
Launched : 2016
Annals of Mens Health and Wellness
ISSN : 2641-7707
Launched : 2017
Journal of Preventive Medicine and Health Care
ISSN : 2576-0084
Launched : 2018
Journal of Chronic Diseases and Management
ISSN : 2573-1300
Launched : 2016
Annals of Vaccines and Immunization
ISSN : 2378-9379
Launched : 2014
JSM Heart Surgery Cases and Images
ISSN : 2578-3157
Launched : 2016
Annals of Reproductive Medicine and Treatment
ISSN : 2573-1092
Launched : 2016
JSM Brain Science
ISSN : 2573-1289
Launched : 2016
JSM Biomarkers
ISSN : 2578-3815
Launched : 2014
JSM Biology
ISSN : 2475-9392
Launched : 2016
Archives of Stem Cell and Research
ISSN : 2578-3580
Launched : 2014
Annals of Clinical and Medical Microbiology
ISSN : 2578-3629
Launched : 2014
JSM Pediatric Surgery
ISSN : 2578-3149
Launched : 2017
Journal of Memory Disorder and Rehabilitation
ISSN : 2578-319X
Launched : 2016
JSM Tropical Medicine and Research
ISSN : 2578-3165
Launched : 2016
JSM Head and Face Medicine
ISSN : 2578-3793
Launched : 2016
JSM Cardiothoracic Surgery
ISSN : 2573-1297
Launched : 2016
JSM Bone and Joint Diseases
ISSN : 2578-3351
Launched : 2017
JSM Bioavailability and Bioequivalence
ISSN : 2641-7812
Launched : 2017
JSM Atherosclerosis
ISSN : 2573-1270
Launched : 2016
Journal of Genitourinary Disorders
ISSN : 2641-7790
Launched : 2017
Journal of Fractures and Sprains
ISSN : 2578-3831
Launched : 2016
Journal of Autism and Epilepsy
ISSN : 2641-7774
Launched : 2016
Annals of Marine Biology and Research
ISSN : 2573-105X
Launched : 2014
JSM Health Education & Primary Health Care
ISSN : 2578-3777
Launched : 2016
JSM Communication Disorders
ISSN : 2578-3807
Launched : 2016
Annals of Musculoskeletal Disorders
ISSN : 2578-3599
Launched : 2016
Annals of Virology and Research
ISSN : 2573-1122
Launched : 2014
JSM Renal Medicine
ISSN : 2573-1637
Launched : 2016
Journal of Muscle Health
ISSN : 2578-3823
Launched : 2016
JSM Genetics and Genomics
ISSN : 2334-1823
Launched : 2013
JSM Anxiety and Depression
ISSN : 2475-9139
Launched : 2016
Clinical Journal of Heart Diseases
ISSN : 2641-7766
Launched : 2016
Annals of Medicinal Chemistry and Research
ISSN : 2378-9336
Launched : 2014
JSM Pain and Management
ISSN : 2578-3378
Launched : 2016
JSM Women's Health
ISSN : 2578-3696
Launched : 2016
Clinical Research in HIV or AIDS
ISSN : 2374-0094
Launched : 2013
Journal of Endocrinology, Diabetes and Obesity
ISSN : 2333-6692
Launched : 2013
Journal of Substance Abuse and Alcoholism
ISSN : 2373-9363
Launched : 2013
JSM Neurosurgery and Spine
ISSN : 2373-9479
Launched : 2013
Journal of Liver and Clinical Research
ISSN : 2379-0830
Launched : 2014
Journal of Drug Design and Research
ISSN : 2379-089X
Launched : 2014
JSM Clinical Oncology and Research
ISSN : 2373-938X
Launched : 2013
JSM Bioinformatics, Genomics and Proteomics
ISSN : 2576-1102
Launched : 2014
JSM Chemistry
ISSN : 2334-1831
Launched : 2013
Journal of Trauma and Care
ISSN : 2573-1246
Launched : 2014
JSM Surgical Oncology and Research
ISSN : 2578-3688
Launched : 2016
Annals of Food Processing and Preservation
ISSN : 2573-1033
Launched : 2016
Journal of Radiology and Radiation Therapy
ISSN : 2333-7095
Launched : 2013
JSM Physical Medicine and Rehabilitation
ISSN : 2578-3572
Launched : 2016
Annals of Clinical Pathology
ISSN : 2373-9282
Launched : 2013
Annals of Cardiovascular Diseases
ISSN : 2641-7731
Launched : 2016
Journal of Behavior
ISSN : 2576-0076
Launched : 2016
Annals of Clinical and Experimental Metabolism
ISSN : 2572-2492
Launched : 2016
Clinical Research in Infectious Diseases
ISSN : 2379-0636
Launched : 2013
JSM Microbiology
ISSN : 2333-6455
Launched : 2013
Journal of Urology and Research
ISSN : 2379-951X
Launched : 2014
Journal of Family Medicine and Community Health
ISSN : 2379-0547
Launched : 2013
Annals of Pregnancy and Care
ISSN : 2578-336X
Launched : 2017
JSM Cell and Developmental Biology
ISSN : 2379-061X
Launched : 2013
Annals of Aquaculture and Research
ISSN : 2379-0881
Launched : 2014
Clinical Research in Pulmonology
ISSN : 2333-6625
Launched : 2013
Journal of Immunology and Clinical Research
ISSN : 2333-6714
Launched : 2013
Annals of Forensic Research and Analysis
ISSN : 2378-9476
Launched : 2014
JSM Biochemistry and Molecular Biology
ISSN : 2333-7109
Launched : 2013
Annals of Breast Cancer Research
ISSN : 2641-7685
Launched : 2016
Annals of Gerontology and Geriatric Research
ISSN : 2378-9409
Launched : 2014
Journal of Sleep Medicine and Disorders
ISSN : 2379-0822
Launched : 2014
JSM Burns and Trauma
ISSN : 2475-9406
Launched : 2016
Chemical Engineering and Process Techniques
ISSN : 2333-6633
Launched : 2013
Annals of Clinical Cytology and Pathology
ISSN : 2475-9430
Launched : 2014
JSM Allergy and Asthma
ISSN : 2573-1254
Launched : 2016
Journal of Neurological Disorders and Stroke
ISSN : 2334-2307
Launched : 2013
Annals of Sports Medicine and Research
ISSN : 2379-0571
Launched : 2014
JSM Sexual Medicine
ISSN : 2578-3718
Launched : 2016
Annals of Vascular Medicine and Research
ISSN : 2378-9344
Launched : 2014
JSM Biotechnology and Biomedical Engineering
ISSN : 2333-7117
Launched : 2013
Journal of Hematology and Transfusion
ISSN : 2333-6684
Launched : 2013
JSM Environmental Science and Ecology
ISSN : 2333-7141
Launched : 2013
Journal of Cardiology and Clinical Research
ISSN : 2333-6676
Launched : 2013
JSM Nanotechnology and Nanomedicine
ISSN : 2334-1815
Launched : 2013
Journal of Ear, Nose and Throat Disorders
ISSN : 2475-9473
Launched : 2016
JSM Ophthalmology
ISSN : 2333-6447
Launched : 2013
Journal of Pharmacology and Clinical Toxicology
ISSN : 2333-7079
Launched : 2013
Annals of Psychiatry and Mental Health
ISSN : 2374-0124
Launched : 2013
Medical Journal of Obstetrics and Gynecology
ISSN : 2333-6439
Launched : 2013
Annals of Pediatrics and Child Health
ISSN : 2373-9312
Launched : 2013
JSM Clinical Pharmaceutics
ISSN : 2379-9498
Launched : 2014
JSM Foot and Ankle
ISSN : 2475-9112
Launched : 2016
JSM Alzheimer's Disease and Related Dementia
ISSN : 2378-9565
Launched : 2014
Journal of Addiction Medicine and Therapy
ISSN : 2333-665X
Launched : 2013
Journal of Veterinary Medicine and Research
ISSN : 2378-931X
Launched : 2013
Annals of Public Health and Research
ISSN : 2378-9328
Launched : 2014
Annals of Orthopedics and Rheumatology
ISSN : 2373-9290
Launched : 2013
Journal of Clinical Nephrology and Research
ISSN : 2379-0652
Launched : 2014
Annals of Community Medicine and Practice
ISSN : 2475-9465
Launched : 2014
Annals of Biometrics and Biostatistics
ISSN : 2374-0116
Launched : 2013
JSM Clinical Case Reports
ISSN : 2373-9819
Launched : 2013
Journal of Cancer Biology and Research
ISSN : 2373-9436
Launched : 2013
Journal of Surgery and Transplantation Science
ISSN : 2379-0911
Launched : 2013
Journal of Dermatology and Clinical Research
ISSN : 2373-9371
Launched : 2013
JSM Gastroenterology and Hepatology
ISSN : 2373-9487
Launched : 2013
Annals of Nursing and Practice
ISSN : 2379-9501
Launched : 2014
JSM Dentistry
ISSN : 2333-7133
Launched : 2013
Author Information X