Vascular Endothelial Growth Factor Blockade Research Articles

Treatment strategy for HER2-negative advanced gastric cancer: salvage-line strategy for advanced gastric cancer.

After immune checkpoint inhibitor (ICI) comes into third-line treatment of advanced gastric cancer, the therapeutic strategy has been dramatically changed. Recent first-line regimen, which consists of ICI and chemotherapeutic agents, prolonged progression-free survival, and subsequent treatment options enabled continuous treatment beyond second-line therapy. Moreover, the advent of vascular endothelial growth factor (VEGF)-targeted agents including angiogenesis inhibitors and TKIs provides an opportunity of considering the interaction between ICI and anti-VEGF agents, and facilitating novel treatment proposal. Although clinical benefit of prolonged VEGF blockade after disease progression has not been confirmed in gastric cancer, combination therapy of cytotoxic agents and anti-VEGF agent, such as irinotecan plus ramucirumab demonstrated favorable objective response rate and progression-free survival in third- or later-line setting. In this review, we discuss recent progress and future directions of later-line treatments of HER2-negative advancer gastric cancer.

Intravitreal ranibizumab injection is associated with an increased risk of chronic kidney disease: a population-based study in Taiwan

Systemic vascular endothelial growth factor (VEGF) blockade has been the top adjunctive chemotherapy since 1990. Anti-VEGF therapy has also been associated with worsened renal function in some patients. However, the association between patient outcomes and use of intravitreal VEGF inhibitors remains controversial. Thus, it is necessary to determine the action mechanism and long-term renal effects of ranibizumab. The National Health Insurance Research Database (NHIRD) is one of the largest global databases that are extensively used for epidemiological research. NHIRD contains the medical information of all insureds, such as inpatient, outpatient, emergency, and traditional Chinese medicine records. We selected subjects aged ≥ 20 years who recently administered ranibizumab for the ranibizumab cohort. Non-ranibizumab cohort consisted of subjects who did not receive ranibizumab, and the index date was a random date between 2008 and 2018. We excluded subjects with missing sex and age records and those in which the date of primary outcome was before the index date. The two cohorts were matched via 1:1 propensity score matching based on sex, age, index year, hypertension, diabetes mellitus, hyperlipidemia, stroke, coronary artery disease, alcoholism, chronic obstructive pulmonary disease, and age-related macular degeneration, retinal vein occlusion, and diabetic macular edema. Medical confounders were angiotensin I-converting enzyme inhibitors, statins, corticosteroids, VEGF inhibitors including bevacizumab and aflibercept, lithium, amphotericin B, adefovir, NSAIDS, cisplatin, and calcineurin inhibitors. Among 48,248 participants aged ≥ 20 years, 24,136 (50%) received ranibizumab (13,565 male [56.20%] and 10,571 female [43.80%]). Moreover, 24,136 participants who did not receive ranibizumab were matched by age, sex, comorbidities, and medications. Subjects who received ranibizumab exhibited a significantly higher risk of CKD than those who did not receive ranibizumab (adjusted hazard ratio = 1.88, 95% CI = 1.79–1.96). Our findings revealed that exposure to intravitreal ranibizumab is an independent risk factor for CKD. Therefore, physicians and ophthalmologists should make the patients aware of such a correlation to increase patient safety and decrease the CKD burden.

Targeting tumor vasculature to improve antitumor activity of T cells armed ex vivo with T cell engaging bispecific antibody

BackgroundSuccess of T cell immunotherapy hinges on the tumor microenvironment (TME), and abnormal tumor vasculature is a hallmark of most solid tumors and associated with immune evasion. The efficacy of...

Do intravitreal anti-vascular endothelial growth factor agents lead to renal adverse events? A pharmacovigilance real-world study.

Intravitreal vascular endothelial growth factor (VEGF) blockade is essential in many macular edema diseases treatment. However, intravitreal VEGF treatment has been reported to lead to deteriorated proteinuria and renal function. This study aimed to explore the relationship between renal adverse events (AEs) and the intravitreal use of VEGF inhibitors. In the FDA's Adverse Event Reporting System (FAERS) database, we searched for renal AEs of patients receiving various anti-VEGF drugs. We performed statistics on renal AEs in patients treated with Aflibercept, Bevacizumab, Ranibizumab, and Brolucizumab (from January 2004 to September 2022) using disproportionate and Bayesian analysis. We also investigated the time to onset, fatality, and hospitalization rates of renal AEs. We identified 80 reports. Renal AEs were most frequently associated with Ranibizumab (46.25%) and Aflibercept (42.50%). However, the association between intravitreal anti-VEGFs and renal AEs was insignificant since the reporting odds ratio of Aflibercept, Bevacizumab, Ranibizumab, and Brolucizumab were 0.23 (0.16, 0.32), 0.24 (0.11, 0.49), 0.37 (0.27, 0.51) and 0.15 (0.04, 0.61), respectively. The median time to renal AEs onsets was 37.5 (interquartile range 11.0-107.3) days. The hospitalization and fatality rates in patients who developed renal AEs were 40.24 and 9.76%, respectively. There are no clear signals for the risk of renal AEs following various intravitreal anti-VEGF drugs based on FARES data.

Gold Nanorod–mesoporous silica core shell nanocomposites for NIR-II photothermal ablation and dual PD-L1/VEGF blockade therapy in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a common malignancy often associated with high angiogenesis and immune suppression in the tumor microenvironment (TME). Targeting of the tumor immune microenvironment via the dual blockade of vascular endothelial growth factor (VEGF) and programmed death-ligand 1 (PD-L1) offers longer progression-free survival as a first-line treatment for patients with unresectable HCC. However, certain critical factors limit the clinical success of this therapy, including low stability of antibody, poor tumor penetration, weak immunogenicity, uncontrollable biological activity, short internal half-life, and failures in lasting antitumor immune response. Nanoparticle-based photothermal therapy (PTT) offers the possibility to amplify anti-tumor immune responses, although some issues still limit the expansion of this strategy, such as limited tumor penetration depth for the activation of immune cells and a weak immune response in a powerful immunosuppressive TME. Here, we designed a nanoplatform (GSBVVP) for combined use with PTT and dual blockade of VEGF and PD-L1 to achieve an enhanced PTT-mediated immune response for the treatment of HCC. This nanoplatform is composed of a gold nanorod/mesoporous silica core-shell nanoparticle, which demonstrated excellent photothermal conversion efficiency and could ablate tumor cells under 1208-nm laser irradiation (NIR-II). GSBVVP was loaded with a small-molecule inhibitor of PD-L1, released by NIR-II triggering. This increased the number of infiltrating CD8+ T cells via the inhibition of T cell PD-1 binding to PD-L1 on tumor cells. A peptide vaccine on the surface of GSBVVP induced anti-VEGF antibody production, thereby blocking the secretion of VEGF by tumor cells in the TME and suppressing the angiogenesis signaling pathway. Animal studies verified that GSBVVP-mediated photothermal immunotherapy significantly inhibited primary tumor growth, suppressed metastasis and prevented tumor recurrence. Our strategy of bridging photothermal ablation with dual blockade VEGF and PD-L1 by nanotechnology may have a great potential for clinical translation, and it is promising for cancer immunotherapy.

Efficacy and Toxicity of Combined Inhibition of EGFR and VEGF in Patients With Advanced Non-small Cell Lung Cancer Harboring Activating EGFR Mutations: A Systematic Review and Meta-analysis.

Dual inhibition of epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGF) pathways have demonstrated promising results for treatment of advanced non-small cell lung cancer. We conducted a systematic review and meta-analysis to assess the efficacy and toxicity of the combined treatment with EGFR tyrosine kinase inhibitors (TKIs) and VEGF blockade for patients with advanced non-small cell lung cancer harboring activating EGFR mutations, in comparison to EGFR TKIs alone. The electronic databases were searched for relevant randomized trials between 2000 and 2022. The primary endpoints were overall survival (OS) and progression-free survival. Secondary endpoints included objective response rate (ORR), disease control rate, and grade ≥3 adverse events (AEs). The pooled hazard ratios (HR) and odds ratios were meta-analyzed using the generic inverse variance and the Mantel-Haenszel methods. A total of 1528 patients from 8 trials were evaluated for analyses. The combination treatment decreased the risk of disease progression by 37% (HR=0.63; 95% CI, 0.56 to 0.72) but had no added benefit on OS compared with EGFR inhibition alone (HR=0.90; 95% CI, 0.76 to 1.05). There was no significant difference in objective response rate or disease control rate between treatments. There was a significantly increased number of AEs reported in the dual treatment arm (odds ratio=3.02; 95% CI, 1.71 to 5.31), with proteinuria and hypertension being the most significantly increased AEs. This meta-analysis suggests combined inhibition of EGFR and VEGF pathways significantly improves progression-free survival, with no OS benefit, and increases AEs. Mature OS data are needed along with results from more trials exploring this strategy with third-generation EGFR TKIs to strengthen these results.

Improvement in visual acuity and retinal phenotype with intravitreal aflibercept (anti-VEGF) in POEMS syndrome with Castleman disease variant

A woman in her thirties with no ophthalmic history presented two days of flashes and floaters. She had reduced right-eye visual acuity, bilateral retinal hemorrhages, and papilledema. She was diagnosed with polyneuropathy, organomegaly, endocrinopathy, myeloma protein, and skin changes (POEMS) syndrome with Castleman disease variant, with elevated systemic levels of vascular endothelial growth factor (VEGF). Three doses of aflibercept (VEGF blocker) were administered to the right eye. The right eye improved from 6/60 to 6/5 after treatment. We suggest that intravitreal VEGF blockade should be considered to preserve vision in patients with POEMS syndrome and high circulating VEGF.

LW-1 MY LIFE WORK : MY RESEARCH WORK FOCUSING ON TUMOR-ASSOCIATED ENDOTHELIAL CELLS ALONG WITH VEGF FOR 30 YEARS

Abstract When I was a medical student, I happened to see the typical histopathology of glioblatoma (GBM) containing expanding necrosis surrounded by enormous glomerulous microvasculature with endothelial proliferation resembling glomeruli in the kidney. It looks like tumor cells starving out due to lack of blood supply with accelerating growth. Since then, I have been fascinated by tumor angiogenesis that might be an attractive therapeutic target.In 1989, vascular endothelial growth factor (VEGF) and vascular permeability factor (VPF) turned out to be identical. In 1992, VEGF expression was distributed surrounding necrosis area in GBM. In 1993, anti-tumor effect of monoclonal antibody for VEGF via inhibition of angiogenesis on various tumor models including glioma was verified in vivo. In 1996, VEGF was found to inhibit the functional maturation of dendritic cells, suggesting that therapeutic blockade of VEGF may improve prospect for immunotherapy as well as inhibition of angiogenesis. Those findings made me excited with visionary idea that combination therapy of anti-VEGF therapy and dendritic cell-based immunotherapy might be a potential therapeutic approach for GBM. Currently, I am dedicated in clinical study of dendritic cell-based immunotherapy and bevacizumab for GBM.Since graduating from medical school and discovery of VEGF in the same era, my clinic and research have been supported by serendipity of a vast of experiences and many people. I would give take-home message to next generation that originality and creativity were cultivated in real-world, and that serendipity and integration were precious for development of basic and clinical research.

Effects of Human Deciduous Dental Pulp-Derived Mesenchymal Stem Cell-Derived Conditioned Medium on the Metabolism of HUVECs, Osteoblasts, and BMSCs.

In this study, we assessed the effects of human deciduous dental pulp-derived mesenchymal stem cell-derived conditioned medium (SHED-CM) on the properties of various cell types. The effects of vascular endothelial growth factor (VEGF) in SHED-CM on the luminal architecture, proliferative ability, and angiogenic potential of human umbilical vein endothelial cells (HUVECs) were determined. We also investigated the effects of SHED-CM on the proliferation of human-bone-marrow mesenchymal stem cells (hBMSCs) and mouse calvarial osteoblastic cells (MC3T3-E1) as well as the expression of ALP, OCN, and RUNX2. The protein levels of ALP were examined using Western blot analysis. VEGF blockade in SHED-CM suppressed the proliferative ability and angiogenic potential of HUVECs, indicating that VEGF in SHED-CM contributes to angiogenesis. The culturing of hBMSCs and MC3T3-E1 cells with SHED-CM accelerated cell growth and enhanced mRNA expression of bone differentiation markers. The addition of SHED-CM enhanced ALP protein expression in hBMSCs and MT3T3-E1 cells compared with that of the 0% FBS group. Furthermore, SHED-CM promoted the metabolism of HUVECs, MC3T3-E1 cells, and hBMSCs. These findings indicate the potential benefits of SHED-CM in bone tissue regeneration.

The potential role of the combined PARP-1 and VEGF inhibition in severe SARS-CoV-2 (COVID-19) infection.

During the evolution of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, several drug candidates have been proposed for repositioning towards a quest for more effective treatments. We reviewed recent literature (Pubmed, Google, Clinicaltrials.gov), as of the middle of May 2021, for evidence regarding the potential benefit from poly(ADP-ribose)-polymerase inhibitors and vascular endothelial growth factor blockade in severe SARS-CoV-2 infection. poly(ADP-ribose)-polymerase inhibitors have been suggested as potential agents against coronavirus disease 2019 (COVID-19) by a variety of mechanisms. vascular endothelial growth factor-associated vascular permeability is implicated with increased vascular leakage and pulmonary oedema. Thus, anti-angiogenesis factors, such as bevacizumab are being investigated in critically ill COVID-19 patients. The synergistic potential of these two classes of inhibitors in severe COVID-19 management could be beneficial. Further research should be carried out in order to support this hypothesis.

Genetic Deletion of Vascular Endothelial Growth Factor Receptor 2 in Endothelial Cells Leads to Immediate Disruption of Tumor Vessels and Aggravation of Hypoxia

Vascular endothelial growth factor (VEGF) blockers are used widely in clinics to target various types of human cancer. Although VEGF blockers exert marked tumor suppressive effects, the therapeutic effects can be limited. Moreover, accumulating evidence shows that VEGF acts not just on endothelial cells but also on various nonendothelial cells, including tumor and immune cells, suggesting a need to revisit the bona fide action of VEGF on endothelial cells using specific genetic mouse models. Herein, tamoxifen-inducible endothelial-specific knockout mice lacking VEGF receptor 2 (Vegfr2), the major signal transducer for VEGF, were used. The initial event resulting from cessation of endothelial Vegfr2 signaling was vascular truncation and fragmentation, rather than maturation of abnormalized vessels. Although deletion of endothelial Vegfr2 suppressed intratumor hemorrhage, it enhanced hypoxia in tumor cells and reduced the number of infiltrating cytotoxic T cells, suggesting a profound reduction in intratumor blood flow. In various tissues, deletion of endothelial Vegfr2 induced regression of healthy capillaries in intestinal villi, substantiating intestinal perforation, which is one of the most common adverse effects of VEGF blockade in humans. Overall, the data suggest that some of the known effects of VEGF blockers on tumor vessels are caused by partial cessation of VEGF signaling, or by actions on nonendothelial cells. The results increasethe understanding of the mechanisms underlying anti-angiogenic therapy.

Evaluation of Intravitreal Aflibercept for the Treatment of Severe Nonproliferative Diabetic Retinopathy

Proactive treatment of nonproliferative diabetic retinopathy (NPDR) reduces the risk of progression to vision-threatening complications. To evaluate vascular endothelial growth factor blockade therapy with intravitreal aflibercept injections in eyes with severe NPDR without diabetic macular edema (DME). The Study of the Efficacy and Safety of Intravitreal Aflibercept for the Improvement of Moderately Severe to Severe Nonproliferative Diabetic Retinopathy (PANORAMA) was a double-masked 100-week randomized clinical trial conducted in multiple centers worldwide. The study included 402 adults with Diabetic Retinopathy Severity Scale (DRSS) level 47 or 53 with no DME and best-corrected visual acuity of 20/40 or better. Intravitreal injections of aflibercept, 2 mg, every 16 weeks after 3 initial monthly doses and one 8-week interval (aflibercept 2q16 group); intravitreal injections of aflibercept, 2 mg, every 8 weeks after 5 initial monthly doses, with pro re nata (PRN) dosing beginning at week 56 (aflibercept 2q8/PRN group); or sham injections (control group). Proportions of eyes with a 2-step or greater improvement in DRSS level, vision-threatening complications, and center-involved DME from baseline to weeks 24, 52, and 100. Among 402 participants (1 eye per participant), the mean (SD) age was 55.7 (10.5) years; 225 (56.0%) were male, and 310 (77.1%) were White. A total of 135 were randomized to the aflibercept 2q16 group, 134 to the aflibercept 2q8/PRN group, and 133 to the control group. At 24 weeks, treatment with aflibercept resulted in a 2-step or greater improvement in DRSS level in 157 of 269 eyes (58.4%) in the combined aflibercept groups vs 8 of 133 eyes (6.0%) in the control group (adjusted difference, 52.3%; 95% CI, 45.2%-59.5%; P < .001). At 52 weeks, 88 of 135 eyes (65.2%) in the aflibercept 2q16 group (adjusted difference, 50.1%; 95% CI, 40.1%-60.1%) and 107 of 134 eyes (79.9%) in the aflibercept 2q8/PRN group (adjusted difference, 64.8%; 95% CI, 55.8%-73.9%) compared with 20 of 133 eyes (15.0%) in the control group (P < .001 for both comparisons) showed a 2-step or greater improvement in DRSS level. Fewer eyes treated with aflibercept vs sham injections developed vision-threatening complications and/or center-involved DME through week 100 (22 of 135 eyes [16.3%] in the 2q16 group [adjusted difference, -34.2%; 95% CI, -44.6 to -23.8] and 25 of 134 eyes [18.7%] in the 2q8/PRN group [adjusted difference, -31.7%; 95% CI, -42.5 to -20.9] compared with 67 of 133 eyes [50.4%] in the control group; P < .001 for both comparisons). No new safety signals were identified. In this study, significantly more eyes with moderately severe to severe NPDR that were treated with aflibercept showed a 2-step or greater improvement in DRSS level at 24, 52, and 100 weeks, and significantly fewer eyes treated with aflibercept vs sham developed vision-threatening complications and center-involved DME. Outcomes on the DRSS between year 1 and 2 emphasize the need for ongoing vascular endothelial growth factor suppression and adherence. ClinicalTrials.gov Identifier: NCT02718326.

Review of intravitreal VEGF inhibitor toxicity and report of collapsing FSGS with TMA in a patient with age-related macular degeneration.

Intravitreal vascular endothelial growth factor (VEGF) receptor blockade is used for a variety of retinal pathologies. These include age-related macular degeneration (AMD), diabetic macular edema (DME) and central retinal vein obstruction. Reports of absorption of intravitreal agents into systemic circulation have increased in number and confirmation of depletion of VEGF has been confirmed. Increasingly there are studies and case reports showing worsening hypertension, proteinuria, renal dysfunction and glomerular disease. The pathognomonic findings of systemic VEGF blockade, thrombotic microangiopathies (TMAs), are also being increasingly reported. One lesion that occurs in conjunction with TMAs that has been described is collapsing focal segmental glomerulosclerosis (cFSGS). cFSGS has been postulated to occur due to TMA-induced chronic glomerular hypoxia. In this updated review we discuss the mechanistic, pharmacological, epidemiological and clinical evidence of intravitreal VEGF toxicity. We review cases of biopsy-proven toxicity presented by our group and other investigators. We also present the third reported case of cFSGS in the setting of intravitreal VEGF blockade with a chronic TMA component that was crucially found on biopsy. This patient is a 74-year-old nondiabetic male receiving aflibercept for AMD. Of the two prior cases of cFSGS in the setting of VEGF blockade, one had AMD and the other had DME. This case solidifies the finding of cFSGS and its association with chronic TMA as a lesion that may be frequently encountered in patients receiving intravitreal VEGF inhibitors.

IMbrave 151: a randomized phase II trial of atezolizumab combined with bevacizumab and chemotherapy in patients with advanced biliary tract cancer.

Background:Biliary tract cancers (BTCs) are heterogenous, highly aggressive tumors that harbor a dismal prognosis for which more effective treatments are needed. The role of cancer immunotherapy in BTC remains to be characterized. The tumor microenvironment (TME) of BTC is highly immunosuppressed and combination treatments are needed to promote effective anticancer immunity. Vascular endothelial growth factor (VEGF) drives immunosuppression in the TME by disrupting antigen presentation, limiting T-cell infiltration, or potentiating immune-suppressive cells. Many VEGF-regulated mechanisms are thought to be relevant to repressed antitumor immunity in BTC, making dual targeting of VEGF and programmed cell death protein 1 (PD-1)/PD-L1 pathways a rational approach. Gemcitabine and Cisplatin (Gem/Cis) can also modulate anticancer immunity through overlapping and complementary mechanisms to those regulated by VEGF. Anti-PD-L1/VEGF inhibition, coupled with chemotherapy, may potentiate antitumor immunity leading to enhanced clinical benefit.Methods:IMbrave 151 is a randomized, double-blind, placebo-controlled, multicenter, international phase II study to evaluate atezolizumab (a PD-L1 inhibitor) in combination with chemotherapy (gemcitabine and cisplatin) and bevacizumab (an anti-VEGF monoclonal antibody) as a first-line treatment for advanced BTC. Approximately 150 patients with previously untreated, advanced BTC will be randomized to either Arm A (atezolizumab + bevacizumab + Gem/Cis) or Arm B (atezolizumab + placebo + Gem/Cis). Randomization is stratified by the presence of metastatic disease, primary tumor location, and geographic region. The primary efficacy endpoint is investigator-assessed progression-free survival (PFS) per RECIST 1.1. Secondary endpoints include objective response rate (ORR), duration of response (DoR), disease control rate (DCR), overall survival (OS), and safety and patient reported outcomes (PROs). Tissue, blood, and stool samples will be collected at baseline and on-treatment in order to perform correlative biomarker analyses.Discussion:IMbrave 151 represents the first randomized study to evaluate combined PD-L1/VEGF blockade on a chemotherapy backbone in BTC.Trial registration:NCT identifier: NCT04677504; EUDRACT number: 2020-003759-14

Sequential Treatment of Bioresponsive Nanoparticles Elicits Antiangiogenesis and Apoptosis and Synergizes with a CD40 Agonist for Antitumor Immunity.

The combination of antiangiogenesis and chemotherapy regimens with cancer immunotherapy has the potential to synergistically boost antitumor immunity. Herein, we report the construction of two bioresponsive nanoparticles, namely, Podo-NP and CbP-NP, comprising prodrugs of podophyllotoxin (Podo) and carboplatin, respectively. Sequential treatment with esterase-responsive Podo-NP, redox-sensitive CbP-NP, and a CD40 agonist promotes antitumor T cell response. Podo-NP suppresses angiogenesis by preventing proliferation and migration of endothelial cells, sprouting of neovessels, formation of tubules, and stabilization of newly formed vessels. Vascular endothelial growth factor blockade and endostatin stimulation normalize tortuous tumor vasculatures to allow efficient infiltration of effector immune cells. Subsequent treatment with CbP-NP arrests the cell-division cycle and elicits the apoptosis of tumor cells. CD40 agonist activates antigen-presenting cells to process the released tumor-associated antigens from dying tumor cells, thus reversing immunosuppressive tumor microenvironments. Sequential delivery of antiangiogenic and chemotherapeutic agents with bioresponsive NPs activates tumor microenvironments and synergizes with CD40 agonist to regress transplanted tumors and inhibit disseminated tumors in a lung cancer mouse model.

Altered Regulation of HIF-1α in Naive- and Drug-Resistant EGFR-Mutant NSCLC: Implications for a Vascular Endothelial Growth Factor-Dependent Phenotype.

The treatment of patients with EGFR-mutant NSCLC with vascular endothelial growth factor (VEGF) inhibitors in combination with EGFR inhibitors provides a greater benefit than EGFR inhibition alone, suggesting that EGFR mutation status may define a patient subgroup with greater benefit from VEGF blockade. The mechanisms driving this potentially enhanced VEGF dependence are unknown. We analyzed the effect of EGFR inhibition on VEGF and HIF-1α in NSCLC models invitro and invivo. We determined the efficacy of VEGF inhibition in xenografts and analyzed the impact of acquired EGFR inhibitor resistance on VEGF and HIF-1α. NSCLC cells with EGFR-activating mutations exhibited altered regulation of VEGF compared with EGFR wild-type cells. In EGFR-mutant cells, EGFR, not hypoxia, was the dominant regulator of HIF-1α and VEGF. NSCLC tumor models bearing classical or exon 20 EGFR mutations were more sensitive to VEGF inhibition than EGFR wild-type tumors, and a combination of VEGF and EGFR inhibition delayed tumor progression. In models of acquired EGFR inhibitor resistance, whereas VEGF remained overexpressed, the hypoxia-independent expression of HIF-1α was delinked from EGFR signaling, and EGFR inhibition no longer diminished HIF-1α or VEGF expression. In EGFR-mutant NSCLC, EGFR signaling is the dominant regulator of HIF-1α and VEGF in a hypoxia-independent manner, hijacking an important cellular response regulating tumor aggressiveness. Cells with acquired EGFR inhibitor resistance retained elevated expression of HIF-1α and VEGF, and the pathways were no longer EGFR-regulated. This supports VEGF targeting in EGFR-mutant tumors in the EGFR inhibitor-naive and refractory settings.

Thrombotic Microangiopathy and Acute Kidney Injury Induced After Intravitreal Injection of Vascular Endothelial Growth Factor Inhibitors VEGF Blockade-Related TMA After Intravitreal Use.

Vascular endothelial growth factor (VEGF) inhibition can cause worsening hypertension, proteinuria, chronic kidney injury, and glomerular disease. Thrombotic microangiopathy (TMA) and other nephrotic disorders have been reported with systemic VEGF blockade. These same agents are given intravitreally for age-related macular degeneration (AMD) and diabetic retinopathy (DR), albeit at lower doses than those given for systemic indications. Systemic absorption of anti-VEGF agents when given intravitreally has been shown consistently along with evidence of significant intravascular VEGF suppression. While worsening hypertension has only been seen in some large-scale studies, case reports show worsening proteinuria and diverse glomerular diseases. These include TMA-associated lesions like focal and segmental glomerulosclerosis with collapsing features (cFSGS). In this paper, we report three cases of TMA likely associated with the use of intravitreal anti-VEGF therapy. These patients developed the signature lesion of VEGF blockade in a 6 to 11 month time frame after starting intravitreal VEGF inhibitors. The literature is reviewed showing similar cases. Intravitreal VEGF blockade may cause these adverse events in a hitherto unidentified subgroup of patients. Well-controlled prospective observational trials are needed to determine the event rate and identify which subgroups of patients are at increased risk. A registry for patients who develop worsening hypertension, proteinuria exacerbation, and glomerular diseases from intravitreal VEGF blockade is proposed.

Worsening proteinuria and renal function after intravitreal vascular endothelial growth factor blockade for diabetic proliferative retinopathy.

Systemic vascular endothelial growth factor (VEGF) inhibitions can induce worsening hypertension, proteinuria and glomerular diseases of various types. These agents can also be used to treat ophthalmic diseases like proliferative diabetic retinopathy, diabetic macular edema, central retinal vein occlusion and age-related macular degeneration. Recently, pharmacokinetic studies confirmed that these agents are absorbed at levels that result in biologically significant suppression of intravascular VEGF levels. There have now been 23 other cases published that describe renal sequela of intravitreal VEGF blockade, and they unsurprisingly mirror known systemic toxicities of VEGF inhibitors. We present three cases where stable levels of proteinuria and chronic kidney disease worsened after initiation of these agents. Two of our three patients were biopsied. The first patient’s biopsy showed diabetic nephropathy and focal and segmental glomerulosclerosis (FSGS) with collapsing features and acute interstitial nephritis (AIN). The second patient’s biopsy showed AIN in a background of diabetic glomerulosclerosis. This is the second patient seen by our group, whose biopsy revealed segmental glomerulosclerosis with collapsing features in the setting of intravitreal VEGF blockade. Though FSGS with collapsing features and AIN are not the typical lesions seen with systemic VEGF blockade, they have been reported as rare case reports previously. In addition to reviewing known elements of intravitreal VEGF toxicity, the cases presented encompass renal pathology data supporting that intravitreal VEGF blockade can result in deleterious systemic and renal pathological disorders.

Claudin-5 Redistribution Induced by Inflammation Leads to Anti-VEGF-Resistant Diabetic Macular Edema.

Approximately 40% of patients with diabetic macular edema (DME) are resistant to anti-vascular endothelial growth factor (VEGF) therapy (rDME). Here, we demonstrate that significant correlations between inflammatory cytokines and VEGF, as observed in naive DME, are lost in patients with rDME. VEGF overexpression in the mouse retina caused delayed inflammatory cytokine upregulation, monocyte/macrophage infiltration (CD11b+ Ly6C+ CCR2+ cells), macrophage/microglia activation (CD11b+ CD80+ cells), and blood-retinal barrier disruption due to claudin-5 redistribution, which did not recover with VEGF blockade alone. Phosphorylated protein analysis of VEGF-overexpressed retinas revealed rho-associated coiled-coil-containing protein kinase (ROCK) activation. Administration of ripasudil, a selective ROCK inhibitor, attenuated retinal inflammation and claudin-5 redistribution. Ripasudil also contributed to the stability of claudin-5 expression by both transcriptional enhancement and degradation suppression in inflammatory cytokine-stimulated endothelium. Notably, the anti-VEGF agent and the ROCK inhibitor were synergic in suppressing cytokine upregulation, monocyte/macrophage infiltration, macrophage/microglia activation, and claudin-5 redistribution. Furthermore, in vitro analysis confirmed that claudin-5 redistribution depends on ROCK2 but not on ROCK1. This synergistic effect was also confirmed in human rDME cases. Our results suggest that ROCK-mediated claudin-5 redistribution by inflammation is a key mechanism in the anti-VEGF resistance of DME.

Calcium dobesilate reduces VEGF signaling by interfering with heparan sulfate binding site and protects from vascular complications in diabetic mice.

Inhibiting vascular endothelial growth factor (VEGF) is a therapeutic option in diabetic microangiopathy. However, VEGF is needed at physiological concentrations to maintain glomerular integrity; complete VEGF blockade has deleterious effects on glomerular structure and function. Anti-VEGF therapy in diabetes raises the challenge of reducing VEGF-induced pathology without accelerating endothelial cell injury. Heparan sulfate (HS) act as a co-receptor for VEGF. Calcium dobesilate (CaD) is a small molecule with vasoprotective properties that has been used for the treatment of diabetic microangiopathy. Preliminary evidence suggests that CaD interferes with HS binding sites of fibroblast growth factor. We therefore tested the hypotheses that (1) CaD inhibits VEGF signaling in endothelial cells, (2) that this effect is mediated via interference between CaD and HS, and (3) that CaD ameliorates diabetic nephropathy in a streptozotocin-induced diabetic mouse model by VEGF inhibition. We found that CaD significantly inhibited VEGF165-induced endothelial cell migration, proliferation, and permeability. CaD significantly inhibited VEGF165-induced phosphorylation of VEGFR-2 and suppressed the activity of VEGFR-2 mediated signaling cascades. The effects of CaD in vitro were abrogated by heparin, suggesting the involvement of heparin-like domain in the interaction with CaD. In addition, VEGF121, an isoform which does not bind to heparin, was not inhibited by CaD. Using the proximity ligation approach, we detected inhibition of interaction in situ between HS and VEGF and between VEGF and VEGFR-2. Moreover, CaD reduced VEGF signaling in mice diabetic kidneys and ameliorated diabetic nephropathy and neuropathy, suggesting CaD as a VEGF inhibitor without the negative effects of complete VEGF blockade and therefore could be useful as a strategy in treating diabetic nephropathy.