Exploring the role of VEGF in Indian Age related macular degeneration

Vorolanib, sunitinib, and axitinib: A comparative study of vascular endothelial growth factor receptor inhibitors and their anti-angiogenic effects

PURPOSE

Pathological angiogenesis and vascular instability are observed in diabetic retinopathy (DR), diabetic macular edema (DME), and wet age-related macular degeneration (wAMD). Many receptor tyrosine kinases (RTKs) including vascular endothelial growth factor receptors (VEGFRs) contribute to angiogenesis, whereas the RTK TIE2 is important for vascular stability. Pan-VEGFR tyrosine kinase inhibitors (TKIs) such as vorolanib, sunitinib, and axitinib are of therapeutic interest over current antibody treatments that target only one or two ligands. This study compared the anti-angiogenic potential of these TKIs.

METHODS

A kinase HotSpot™ assay was conducted to identify TKIs inhibiting RTKs associated with angiogenesis and vascular stability. Half-maximal inhibitory concentration (IC50) for VEGFRs and TIE2 was determined for each TKI. In vitro angiogenesis inhibition was investigated using a human umbilical vein endothelial cell sprouting assay, and in vivo angiogenesis was studied using the chorioallantoic membrane assay. Melanin binding was assessed using a melanin-binding assay. Computer modeling was conducted to understand the TIE2-axitinib complex as well as interactions between vorolanib and VEGFRs.

RESULTS

Vorolanib, sunitinib, and axitinib inhibited RTKs of interest in angiogenesis and exhibited pan-VEGFR inhibition. HotSpot™ assay and TIE2 IC50 values showed that only axitinib potently inhibited TIE2 (up to 89%). All three TKIs effectively inhibited angiogenesis in vitro. In vivo, TKIs were more effective at inhibiting VEGF-induced angiogenesis than the anti-VEGF antibody bevacizumab. Of the three TKIs, only sunitinib bound melanin. TKIs differ in their classification and binding to VEGFRs, which is important because type II inhibitors have greater selectivity than type I TKIs.

CONCLUSIONS

Vorolanib, sunitinib, and axitinib exhibited pan-VEGFR inhibition and inhibited RTKs associated with pathological angiogenesis. Of the three TKIs, only axitinib potently inhibited TIE2 which is an undesired trait as TIE2 is essential for vascular stability. The findings support the use of vorolanib for therapeutic inhibition of angiogenesis observed in DR, DME, and wAMD.

Efficacy, Safety and Immunogenicity of Sun's Ranibizumab Biosimilar in Neovascular Age-Related Macular Degeneration: A Phase 3, Double-Blind Comparative Study

INTRODUCTION

The study aimed to evaluate comparability in terms of efficacy, safety and immunogenicity of Sun's ranibizumab biosimilar with reference ranibizumab in patients with neovascular age-related macular degeneration (nAMD).

METHODS

This prospective, randomised, double-blind, two-group, parallel-arm, multicentre, phase 3 comparative study included patients with nAMD ≥ 50 years, randomised (in a 2:1 ratio) in a double-blind manner to receive 0.5 mg (0.05 mL) intravitreal injection of either Sun's ranibizumab or reference ranibizumab in the study eye every 4 weeks until week 16 (total of four doses).

RESULTS

Primary endpoint results demonstrated equivalence in the proportion of patients who lost fewer than 15 letters from baseline best-corrected visual acuity (BCVA) to the end of week 16 (99% of patients in Sun's ranibizumab and 100% in reference ranibizumab; p > 0.9999), with the proportional difference (90% confidence interval) at -1% (-2.51, +0.61) lying within a pre-specified equivalence margin. Visual acuity improved by 15 or more letters in 43% of Sun's ranibizumab group and 37% of the reference ranibizumab group (p = 0.4267). The mean increase in BCVA was 15.7 letters in Sun's ranibizumab group and 14.6 letters in the reference ranibizumab group (p < 0.001 within both groups and p = 0.5275 between groups). The mean change in central macular thickness was comparable between groups (p = 0.7946). Anti-ranibizumab antibodies were found in one patient of the reference ranibizumab group, while neutralising antibodies were not found in any patients. Both products were well tolerated.

CONCLUSION

Sun's ranibizumab biosimilar is found to be therapeutically equivalent to reference ranibizumab in patients with nAMD. There were no additional safety or immunogenicity concerns.

TRIAL REGISTRATION

CTRI/2020/09/027629, registered on 07 September 2020.

Evaluation of vascular endothelial growth factor (VEGF) level in the tears and serum of age-related macular degeneration patients

Age-related macular degeneration (AMD) is an important cause of irreversible central blindness worldwide. Clinical manifestations range from asymptomatic in early and intermediate AMD to significant vision loss in late AMD. Approximately 10% of cases of early AMD eventually progress to the late advanced stage, influenced by the upregulation of vascular endothelial growth factor (VEGF). In this study, we evaluated VEGF concentration in the tears and serum of AMD patients. Our study revealed a significantly higher level of VEGF in the tears of patients with AMD compared with controls. The tear VEGF level has high sensitivity and specificity, and is significantly related to the severity of AMD, whilst serum VEGF level is non-specific and non-predictive of AMD severity. Thus, VEGF level in the tears may be used as a non-invasive biomarker for AMD progression. A large cohort study is needed for further verification.

VEGFA Haplotype and VEGF-A and VEGF-R2 Protein Associations with Exudative Age-Related Macular Degeneration

Our study aimed to reveal the associations between VEGFA SNPs (rs1570360, rs699947, rs3025033, and rs2146323), their haplotypes, VEGF-A and VEGF-R2 serum concentrations, and early and exudative AMD. A total of 339 subjects with early AMD and 419 with exudative AMD groups, and 374 healthy subjects, were genotyped for four VEGFA SNPs (rs1570360, rs699947, rs3025033, and rs2146323). VEGF-A and VEGFR-2 serum concentrations were measured in exudative AMD and controls. The results revealed that rs3025033 G allele was significantly associated with lower odds of exudative AMD under the dominant model (OR = 0.67; 95% CI: 0.49–0.80; p = 0.0088) and additive (OR = 0.7; 95% CI: 0.54–0.90; p = 0.0058) models after Bonferroni correction. In the female group, rs3025033 AG genotype was associated with exudative AMD under the codominant model (OR = 0.57; 95% CI: 0.37–0.87; p = 0.009) and G allele under the dominant (OR = 0.55; 95% CI: 0.37–0.82; p = 0.0032) and additive models (OR = 0.60; 95% CI: 0.42–0.84; p = 0.0028). Haplotype analysis revealed that individuals carrying rs1570360, rs699947, rs3025033, and rs2146323 haplotype A-A-G-A had decreased risk of exudative AMD (OR = 0.46, 95% CI: 0.23–0.90; p = 0.023). The VEGF-A and VEGF-R2 serum concentrations did not differ between study groups; we found that patients with exudative AMD carrying at least one C allele at rs699947 have statistically significantly higher VEGF-A serum concentrations compared to AA genotype carriers (485.95 (945.93) vs. 194.97 (-), respectively, p = 0.046). In conclusion, we found that VEGFA rs3025033 and haplotype rs1570360A-rs699947A-rs3025033G- rs2146323A play a protective role for exudative AMD in the Caucasian population. Furthermore, rs699947 is associated with elevated VEGF-A serum concentrations in exudative AMD.

Genotyping of Clinical Parameters in Age-Related Macular Degeneration

Background

Methods

Results

Conclusion

Modulated anti-VEGF therapy under the influence of lipid metabolizing proteins in Age related macular degeneration: a pilot study

Age-related macular degeneration (AMD) is a devastating retinal disease that results in irreversible vision loss in the aged population. The complex genetic nature and degree of genetic penetrance require a redefinition of the current therapeutic strategy for AMD. We aimed to investigate the role of modifiers for current anti-VEGF therapy especially for non-responder AMD patients. We recruited 78 wet AMD cases (out of 278 AMD patients) with their socio-demographic and treatment regimen. Serum protein levels were estimated by ELISA in AMD patients. Data pertaining to the number of anti-VEGF injections given (in 1 year) along with clinical images (FFA and OCT) of AMD patients were also included. Visual acuity data (logMAR) for 46 wet AMD cases out of a total of 78 patients were also retrieved to examine the response of anti-VEGF injections in wet AMD cases. Lipid metabolizing genes (LIPC and APOE) have been identified as chief biomarkers for anti-VEGF response in AMD patients. Both genotypes 'CC' and 'GC' of LIPC have found to be associated with a number of anti-VEGF injections in AMD patients which could influence the expression of B3GALTL,HTRA1, IER3, LIPC and SLC16A8 proteins in patients bearing both genotypes as compared to reference genotype. Elevated levels of APOE were also observed in group 2 wet AMD patients as compared to group 1 suggesting the significance of APOE levels in anti-VEGF response. The genotype of B3GALTL has also been shown to have a significant association with the number of anti-VEGF injections. Moreover, visual acuity of group 1 (≤ 4 anti-VEGF injections/year) AMD patients was found significantly improved after 3 doses of anti-VEGF injections and maintained longitudinally as compared to groups 2 and 3. Lipid metabolising genes may impact the outcome of anti-VEGF AMD treatment.

Treatment Landscape of Macular Disorders in Indian Patients with the Advent of Razumab™ (World's First Biosimilar Ranibizumab): A Comprehensive Review

Ranibizumab is approved for the treatment of several macular disorders, including wet age-related macular degeneration (wet AMD), diabetic macular edema (DME), retinal vein occlusion (RVO) and myopic choroidal neovascularization (mCNV), among others. The unaffordability of the innovator ranibizumab among patients from developing countries such as India led to the development of the world’s first biosimilar ranibizumab, which is a cost-effective alternative that does not compromise efficacy and safety. Razumab™, developed and produced by Intas Pharmaceuticals Ltd., India, is the world’s first biosimilar of ranibizumab, and is approved in India for the treatment of various macular disorders, including wet AMD, DME, RVO and mCNV. The efficacy and safety of Razumab for the treatment of these macular disorders have been evaluated in both prospective and real-world retrospective studies. Razumab has shown an efficacy similar to that of the innovator ranibizumab, achieving improved visual acuity, as measured by the best corrected visual acuity, and reduction in the central macular thickness, leading to improved patient outcomes. The safety profile of Razumab is comparable to that of the innovator ranibizumab and is well tolerated without any new safety concerns. Here, we review the clinical and real-world data of Razumab in the treatment of macular disorders.

Sleeping pattern and activities of daily living modulate protein expression in AMD

Degeneration of macular photoreceptors is a prominent characteristic of age-related macular degeneration (AMD) which leads to devastating and irreversible vision loss in the elderly population. In this exploratory study, the contribution of environmental factors on the progression of AMD pathology by probing the expression of candidate proteins was analyzed. Four hundred and sixty four participants were recruited in the study comprising of AMD (n = 277) and controls (n = 187). Genetics related data was analyzed to demonstrate the activities of daily living (ADL) by using regression analysis and statistical modeling, including contrast estimate, multinomial regression analysis in AMD progression. Regression analysis revealed contribution of smoking, alcohol, and sleeping hours on AMD by altered expression of IER-3, HTRA1, B3GALTL, LIPC and TIMP3 as compared to normal levels. Contrast estimate supports the gender polarization phenomenon in AMD by significant decreased expression of SLC16A8 and LIPC in control population which was found to be unaltered in AMD patients. The smoking, food habits and duration of night sleeping hours also contributed in AMD progression as evident from multinomial regression analysis. Predicted model (prediction estimate = 86.7%) also indicated the crucial role of night sleeping hours along with the decreased expression of TIMP-3, IER3 and SLC16A8. Results revealed an unambiguous role of environmental factors in AMD progression mediated by various regulatory proteins which might result in intermittent AMD phenotypes and possibly influence the outcome of anti-VEGF treatment.

Safety and efficacy of Razumab™ (world's first biosimilar ranibizumab) in wet age-related macular degeneration: a post-marketing, prospective ASSET study

BACKGROUND

Razumab™ (world's first biosimilar ranibizumab) is approved for several macular disorders including wet age-related macular degeneration (AMD). We evaluated the safety and efficacy of biosimilar ranibizumab in wet AMD.

METHODS

This prospective, multicentre, rAnibizumab bioSimilar Safety Efficacy postmarkeTing (ASSET) study enrolled patients aged ≥ 50 years with wet AMD having best-corrected visual acuity (BCVA) between 20/40 and 20/320. The patients received intravitreal biosimilar ranibizumab 0.5 mg every 4 weeks for 24 weeks. Safety endpoints included the incidence of adverse events (AEs), serious AEs (SAEs), and immunoreactivity after 6 months. The efficacy endpoints were the proportion of patients who lose fewer than 15 letters, increase in BCVA, change in central retinal thickness (CRT), and change in Visual Function Questionnaire-25 (VFQ-25) score, from baseline to 24 weeks.

RESULTS

Of the 126 enrolled patients, majority (95.24%) of the patients received all 6 doses of biosimilar ranibizumab (total 3 mg). Nineteen AEs were reported (n = 16; 12.7%); majority (78.9%) were mild. There were no serious AEs reported, except one AE of death which was unrelated to the study drug. None of the patients discontinued the study due to an AE. The most common ocular AE was increase in intraocular pressure (4 events) and non-ocular AE was pyrexia (5 events). A total of 7.9% (10/126) patients prior to dosing and 7.1% (9/126) patients post-treatment were positive for anti-ranibizumab antibodies. No AEs suggestive of immunogenicity were noted. At 24-weeks, 97.60% patients in the intent-to-treat (ITT) population (N = 125) and 97.41% patients in the per-protocol (PP) population (N = 116) lost < 15 letters from baseline visual acuity. In the ITT and PP populations, 31.20% and 32.76% patients, respectively, showed improved visual acuity by ≥ 15 letters. Significant improvements in BCVA (mean difference: 8.8, 9.2, p < 0.001 for ITT, PP) and VFQ-25 (8.5, 9.2, p < 0.001 for ITT, PP) were seen; CRT reduced significantly (125 µm, 119.3 µm, p < 0.001 for ITT, PP).

CONCLUSION

Razumab™ (world's first biosimilar ranibizumab) was well-tolerated without new safety concerns and significantly improved visual acuity in wet AMD patients. Trial registration CTRI/2016/03/006739. Registered 18 March 2016-Prospectively registered, http://ctri.nic.in/Clinicaltrials/pmaindet2.php?trialid=13141&EncHid=&userName=2016/03/006739.

CCL2 single nucleotide polymorphism of rs1024611 implicates prominence of inflammatory cascade by univariate modeling in Indian AMD

Background

The role of chemotactic protein CCL2/MCP-1 has been widely explored in age related macular degeneration (AMD) patients as well as animal models through our previous studies.

Aim

Aim of the study was to examine the association of another variance of CCL2, rs1024611 in pathophysiology of AMD.

Methods

This particular SNP has been found to be involved in inflammatory processes in various diseases. Total 171 subjects were recruited in the study with all demographic details by administering a standard questionnaire. SNP analysis was performed with TaqMan assay. Linear univariate and ANCOVA modeling was performed to show the interaction of rs1024611 with another SNP variant of CCL-2/CCR-2 (rs4586 and rs1799865) and impact of individual genotypes on CCL-2 expression in the context of AMD pathology.

Results

Results showed that both heterozygous (AG, p = 0.01) and homozygous (GG, p = 0.0001) genotypes are associated with AMD pathology. Allele frequency analysis showed that ‘G’ allele is frequent in AMD patients as compared to controls (p = 0.0001). Moreover, AMD patients who smoke were found to be associated with ‘AG’ genotype (p = 0.0145). Although, we did not find any significant interaction between the SNP variants by linear univariate analysis but results show the effect of ‘CT’ genotype on ‘TT’ genotype in rs4586 by considering rs1024611 as covariate.

Conclusion

Based on these results it is imperative that CCL2 mediated pathology may be associated with AMD.

Quercetin Mitigates Inflammatory Responses Induced by Vascular Endothelial Growth Factor in Mouse Retinal Photoreceptor Cells through Suppression of Nuclear Factor Kappa B

Retinal vascular endothelial growth factor (VEGF) increased by neovascularization is well known as a pathogenic factor in ocular neovascular diseases. However, it is still unclear how retinal neurons are damaged by VEGF. The aims of this study are to demonstrate the inflammatory protein expression regulated by VEGF using mouse photoreceptor-derived cells and the protective effect of quercetin against VEGF-induced inflammatory response. Expression and phosphorylation of protein and expression of mRNA were detected by immunoblot and reverse transcriptase polymerase chain reaction. VEGF-induced degradation of limiting membrane and translocation of nuclear factor kappa B (NF-κB) were analyzed by immunocytochemistry. VEGF treatment activated angiogenic signaling pathway in photoreceptor cells. In addition, adhesion molecules and matrix metalloproteinases were increased in VEGF-treated photoreceptor cells. All these events were reversed by quercetin. Zona occludins-1 and β-catenin decreased by VEGF were recovered by quercetin. NF-κB signaling pathway regulated by VEGF through phosphorylations of mitogen-activated protein kinases (MAPK) and protein kinase B (Akt) was suppressed by quercetin. These results suggest that quercetin suppressed VEGF-induced excessive inflammatory response in retinal photoreceptor cells by inactivation of NF-κB signals through inhibition of MAPKs and Akt. These data may provide a basic information for development of pharmaceuticals or nutraceuticals for treatment of retinal diseases caused by excessive VEGF.

Serum Levels of TIMP-3, LIPC, IER3, and SLC16A8 in CFH-Negative AMD Cases

AMD is a complex eye disease predominantly occurring in aged population. Till now about 53 genetic loci have been found to be associated with the AMD pathology. AMD pathogenesis is being increasingly known to progress through mechanisms independent of the CFH mediated pathway. Therefore, our aim for current study was to examine the genes by analyzing their expression levels in AMD. We recruited about 50 AMD and same number of age matched controls. We analyzed the CFH duplication and deletion by multiplex ligation probe amplification (MLPA) and found no duplication and deletion in CFH gene in AMD patients. We also estimated the IER-3, SLC16A8, LIPC, and TIMP-3 expression levels in both CFH-negative AMD cases (i.e. no duplication and deletion in CFH gene) besides examining these in AMD and controls. We found that the expression level of LIPC, SLC16A8, and TIMP-3 was significantly associated with AMD pathology in both groups (LIPC: P = 0.008, SLC16A8: P < 0.001, TIMP-3: P < 0.001, respectively). However, we did not find any significant difference in IER-3 levels in AMD and controls. Therefore, the evidence from current study, suggests that AMD pathology may be mediated through mechanistic pathways linked to other genetic loci. J. Cell. Biochem. 118: 2087-2095, 2017. © 2016 Wiley Periodicals, Inc.