Current and Future Anti-VEGF Agents for Neovascular Age-Related Macular Degeneration

Phase I DAVIO Trial: EYP-1901 Bioerodible, Sustained-Delivery Vorolanib Insert in Patients With Wet Age-Related Macular Degeneration

Purpose

To evaluate safety and tolerability of EYP-1901, an intravitreal insert containing vorolanib, a pan-VEGF receptor inhibitor packaged in a bioerodible delivery technology (Durasert E™) for sustained delivery, in patients with wet age-related macular degeneration (wAMD) previously treated with anti-VEGF therapy.

Design

Phase I, multicenter, prospective, open-label, dose-escalation trial.

Participants

Patients with wAMD and evidence of prior anti-VEGF therapy response.

Methods

Patients received a single intravitreal injection of EYP-1901.

Main Outcome Measures

The primary objective was to evaluate safety and tolerability of EYP-1901. Secondary objectives assessed biologic activity of EYP-1901 including best-corrected visual acuity (BCVA) and central subfield thickness (CST). Exploratory analyses included reduction in anti-VEGF treatment burden and supplemental injection-free rates.

Results

Seventeen patients enrolled in the 440 μg (3 patients), 1030 μg (1 patient), 2060 μg (8 patients), and 3090 μg (5 patients) dose cohorts. No dose-limiting toxicity, ocular serious adverse events (AEs), or systemic AEs related to EYP-1901 were observed. There was no evidence of ocular or systemic toxicity related to vorolanib or the delivery technology. Moderate ocular treatment-emergent AEs (TEAEs) included reduced visual acuity (2/17) and retinal exudates (3/17). One patient with reduced BCVA had 3 separate reductions of 17, 18, and 16 letters, and another had a single drop of 25 letters. One severe TEAE, neovascular AMD (i.e., worsening/progressive disease activity), was reported in 1 of 17 study eyes but deemed unrelated to treatment. Mean change from baseline in BCVA was -1.8 letters and -5.4 letters at 6 and 12 months. Mean change from baseline in CST was +1.7 μm and +2.4 μm at 6 and 12 months. Reduction in treatment burden was 74% and 71% at 6 and 12 months. Of 16 study eyes, 13, 8, and 5 were injection-free up to 3, 6, and 12 months.

Conclusion

In the DAVIO trial (ClinicalTrials.gov identifier, NCT04747197), EYP-1901 had a favorable safety profile and was well tolerated in previously treated eyes with wAMD. Measures of biologic activity remained relatively stable following a single EYP-1901 injection. These preliminary data support ongoing phase II and planned phase III trials to assess efficacy and safety.

Financial Disclosures

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Biosimilars of anti-vascular endothelial growth factor for ophthalmic diseases: A review

The development of intravitreally injected biologic medicines (biologics) acting against vascular endothelial growth factor (VEGF) substantially improved the clinical outcomes of patients with common VEGF-driven retinal diseases. The relatively high cost of branded agents, however, represents a financial burden for most healthcare systems and patients, likely resulting in impaired access to treatment and poorer clinical outcomes for some patients. Biosimilar medicines (biosimilars) are clinically equivalent, potentially economic alternatives to reference products. Biosimilars approved by leading health authorities have been demonstrated to be similar to the reference product in a comprehensive comparability exercise, generating the totality of evidence necessary to support analytical, pre-clinical, and clinical biosimilarity. Anti-VEGF biosimilars have been entering the field of ophthalmology in the US since 2022. We review regulatory and scientific concepts of biosimilars, the biosimilar development landscape in ophthalmology, with a specific focus on anti-VEGF biosimilars, and discuss opportunities and challenges facing the uptake of biosimilars.

Epitope-specific antibody fragments block aggregation of AGelD187N, an aberrant peptide in gelsolin amyloidosis

Aggregation of aberrant fragment of plasma gelsolin, AGelD187N, is a crucial event underlying the pathophysiology of Finnish gelsolin amyloidosis, an inherited form of systemic amyloidosis. The amyloidogenic gelsolin fragment AGelD187N does not play any physiological role in the body, unlike most aggregating proteins related to other protein misfolding diseases. However, no therapeutic agents that specifically and effectively target and neutralize AGelD187N exist. We employed phage display technology to identify novel single-chain variable fragments (scFvs) that bind to different epitopes in the monomeric AGelD187N that were further maturated by variable domain shuffling and converted to antigen-binding fragment (Fab) antibodies. The generated antibody fragments had nanomolar binding affinity for full-length AGelD187N, as evaluated by biolayer interferometry. Importantly, all four Fabs selected for functional studies efficiently inhibited the amyloid formation of full-length AGelD187N as examined by thioflavin fluorescence assay and transmission electron microscopy. Two Fabs, neither of which bound to the previously proposed fibril-forming region of AGelD187N, completely blocked the amyloid formation of AGelD187N. Moreover, no small soluble aggregates, which are considered pathogenic species in protein misfolding diseases, were formed after successful inhibition of amyloid formation by the most promising aggregation inhibitor, as investigated by size exclusion chromatography combined with multi-angle light scattering. We conclude that all regions of the full-length AGelD187N are important in modulating its assembly into fibrils and that the discovered epitope-specific anti-AGelD187N antibody fragments provide a promising starting point for a disease-modifying therapy for gelsolin amyloidosis, which is currently lacking.

Niosome-encapsulated auraptene reduced the mRNA expression of VEGF-A and PDGFs genes in human retina-derived RPE cell line

AIM

To evaluate the effect of auraptene (AUR) treatment in forms of free and encapsulated in niosome nanoparticles by investigating the mRNA expression level of vascular endothelium growth factor (VEGF)-A and platelet-derived growth factors (PDGFs) in human retinal pigment epithelium (RPE) cell line.

METHODS

Niosome nanocarriers were produced using two surfactants Span 60 and Tween 80. RPE cell line was treated with both free AUR and niosome-encapsulated. Optimum dosage of treatments was calculated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Expression of VEGF-A and PDGF-A, PDGF-B, PDGF-C, PDGF-D genes was measured after total RNA extraction and cDNA synthesis, using real-time polymerase chain reaction (RT-PCR).

RESULTS

The highest entrapment efficiency (EE) was achieved by Span 60:cholesterol (1:1) with 64.3%. The half maximal inhibitory concentration (IC50) of free and niosome-encapsulated AUR were 38.5 and 27.78 µg/mL, respectively. Release study revealed that niosomal AUR had more gradual delivery to the cells. RT-PCR results showed reduced expression levels of VEGF-A, PDGF-A, PDGF-B, PDGF-C, and PDGF-D after treatment with both free and niosomal AUR.

CONCLUSION

Niosomal formulation of Span 60: cholesterol (1:1) is an effective drug delivery approach to transfer AUR to RPE cells. VEGF-A, PDGF-A, PDGF-B, PDGF-C, and PDGF-D are four angiogenic factors, inhibiting which by niosomal AUR may be effective in age-related macular degeneration.

Barcode lipids for absolute quantitation of liposomes in ocular tissues

Lipid-based drug formulations are promising systems for improving delivery of drugs to ocular tissues, such as retina. To develop lipid-based systems further, an improved understanding of their pharmacokinetics is required, but high-quality in vivo experiments require a large number of animals, raising ethical and economic questions. In order to expedite in vivo kinetic testing of lipid-based systems, we propose a barcode approach that is based on barcoding liposomes with non-endogenous lipids. We developed and evaluated a liquid-chromatography-mass spectrometry method to quantify many liposomes simultaneously in aqueous humor, vitreous, and neural retina at higher than ±20% precision and accuracy. Furthermore, we showed in vivo suitability of the method in pharmacokinetic evaluation of six different liposomes after their simultaneous injection into the rat vitreal cavity. We calculated pharmacokinetic parameters in vitreous and aqueous humor, quantified liposome concentrations in the retina, and quantitated retinal distribution of the liposomes in the rats. Compared to individual injections of the liposome formulations, the barcode-based study design enabled reduction of animal numbers from 72 to 12. We believe that the proposed approach is reliable and will reduce and refine ocular pharmacokinetic experiments with liposomes and other lipid-based systems.

High throughput functional profiling of genes at intraocular pressure loci reveals distinct networks for glaucoma

INTRODUCTION

Primary open angle glaucoma (POAG) is a leading cause of blindness globally. Characterized by progressive retinal ganglion cell degeneration, the precise pathogenesis remains unknown. Genome-wide association studies (GWAS) have uncovered many genetic variants associated with elevated intraocular pressure (IOP), one of the key risk factors for POAG. We aimed to identify genetic and morphological variation that can be attributed to trabecular meshwork cell (TMC) dysfunction and raised IOP in POAG.

METHODS

62 genes across 55 loci were knocked-out in a primary human TMC line. Each knockout group, including five non-targeting control groups, underwent single-cell RNA-sequencing (scRNA-seq) for differentially-expressed gene (DEG) analysis. Multiplexed fluorescence coupled with CellProfiler image analysis allowed for single-cell morphological profiling.

RESULTS

Many gene knockouts invoked DEGs relating to matrix metalloproteinases and interferon-induced proteins. We have prioritized genes at four loci of interest to identify gene knockouts that may contribute to the pathogenesis of POAG, including ANGPTL2, LMX1B, CAV1, and KREMEN1. Three genetic networks of gene knockouts with similar transcriptomic profiles were identified, suggesting a synergistic function in trabecular meshwork cell physiology. TEK knockout caused significant upregulation of nuclear granularity on morphological analysis, while knockout of TRIOBP, TMCO1 and PLEKHA7 increased granularity and intensity of actin and the cell-membrane.

CONCLUSION

High-throughput analysis of cellular structure and function through multiplex fluorescent single-cell analysis and scRNA-seq assays enabled the direct study of genetic perturbations at the single-cell resolution. This work provides a framework for investigating the role of genes in the pathogenesis of glaucoma and heterogenous diseases with a strong genetic basis.

AI-based support for optical coherence tomography in age-related macular degeneration

Artificial intelligence (AI) has emerged as a transformative technology across various fields, and its applications in the medical domain, particularly in ophthalmology, has gained significant attention. The vast amount of high-resolution image data, such as optical coherence tomography (OCT) images, has been a driving force behind AI growth in this field. Age-related macular degeneration (AMD) is one of the leading causes for blindness in the world, affecting approximately 196 million people worldwide in 2020. Multimodal imaging has been for a long time the gold standard for diagnosing patients with AMD, however, currently treatment and follow-up in routine disease management are mainly driven by OCT imaging. AI-based algorithms have by their precision, reproducibility and speed, the potential to reliably quantify biomarkers, predict disease progression and assist treatment decisions in clinical routine as well as academic studies. This review paper aims to provide a summary of the current state of AI in AMD, focusing on its applications, challenges, and prospects.

Ferroptosis as a potential therapeutic target for age-related macular degeneration

Cell death plays a crucial part in the process of age-related macular degeneration (AMD), but its mechanisms remain elusive. Accumulating evidence suggests that ferroptosis, a novel form of regulatory cell death characterized by iron-dependent accumulation of lipid hydroperoxides, has a crucial role in the pathogenesis of AMD. Numerous studies have suggested that ferroptosis participates in the degradation of retinal cells and accelerates the progression of AMD. Furthermore, inhibitors of ferroptosis exhibit notable protective effects in AMD, underscoring the significance of ferroptosis as a pivotal mechanism in the death of retinal cells during the process of AMD. This review aims to summarize the molecular mechanisms of ferroptosis in AMD, enumerate potential inhibitors and discuss the challenges and future opportunities associated with targeting ferroptosis as a therapeutic strategy, providing important information references and insights for the prevention and treatment of AMD.

Next generation therapeutics for retinal neurodegenerative diseases

Neurodegenerative diseases affecting the visual system encompass glaucoma, macular degeneration, retinopathies, and inherited genetic disorders such as retinitis pigmentosa. These ocular pathologies pose a serious burden of visual impairment and blindness worldwide. Current treatment modalities include small molecule drugs, biologics, or gene therapies, most of which are administered topically as eye drops or as injectables. However, the topical route of administration faces challenges in effectively reaching the posterior segment and achieving desired concentrations at the target site, while injections and implants risk severe complications, such as retinal detachment and endophthalmitis. This necessitates the development of innovative therapeutic strategies that can prolong drug release, deliver effective concentrations to the back of the eye with minimal systemic exposure, and improve patient compliance and safety. In this review, we introduce retinal degenerative diseases, followed by a discussion of the existing clinical standard of care. We then delve into detail about drug and gene delivery systems currently in preclinical and clinical development, including formulation and delivery advantages/drawbacks, with a special emphasis on potential for clinical translation.

Association between age-related macular degeneration and risk of incident cancer

BACKGROUND/AIMS

Age-related macular degeneration (AMD) and cancer may share similar risk factors, indicating possible common pathogenic pathways. We aimed to describe the site-specific cancer risk based on the relationship of AMD with visual disability (VD) status.

METHODS

This was a population-based cohort study using data from the Korean National Health Insurance Service database (2009-2019) including patients who participated in a national health screening programme in 2009. The subjects were categorised based on the presence of AMD and VD. The occurrence of cancer was identified using principal diagnosis according to the International Classification of Disease, 10th revision codes in claims data. The Cox regression hazard model was used to compare HRs of site-specific cancer.

RESULTS

Among 4 088 814 participants, 51 596 had AMD of which 3683 subjects had VD. The mean follow-up period was 9.6 years. The overall cancer risk was generally null, but the risk of hypervascular cancer such as thyroid cancer (adjusted HR (aHR) 1.10, 95% CI 1.00 to 1.20) and renal cancer (aHR 1.16, 95% CI 1.00 to 1.33) was higher and the risk of stomach cancer (aHR 0.89, 95% CI 0.84 to 0.94) was lower in the AMD group than in the non-AMD group.

CONCLUSION

This study demonstrated a possible association between AMD and several cancers. Increased renal and thyroid cancer risk among patients with AMD could indicate that AMD is associated with hypervascular cancer. Further studies in which additional databases are used and the underlying detailed mechanisms evaluated are needed to validate our results.

Hydrogels in Ophthalmology: Novel Strategies for Overcoming Therapeutic Challenges

The human eye's intricate anatomical and physiological design necessitates tailored approaches for managing ocular diseases. Recent advancements in ophthalmology underscore the potential of hydrogels as a versatile therapeutic tool, owing to their biocompatibility, adaptability, and customizability. This review offers an exploration of hydrogel applications in ophthalmology over the past five years. Emphasis is placed on their role in optimized drug delivery for the posterior segment and advancements in intraocular lens technology. Hydrogels demonstrate the capacity for targeted, controlled, and sustained drug release in the posterior segment of the eye, potentially minimizing invasive interventions and enhancing patient outcomes. Furthermore, in intraocular lens domains, hydrogels showcase potential in post-operative drug delivery, disease sensing, and improved biocompatibility. However, while their promise is immense, most hydrogel-based studies remain preclinical, necessitating rigorous clinical evaluations. Patient-specific factors, potential complications, and the current nascent stage of research should inform their clinical application. In essence, the incorporation of hydrogels into ocular therapeutics represents a seminal convergence of material science and medicine, heralding advancements in patient-centric care within ophthalmology.

Patient-Centered Economic Burden of Exudative Age-Related Macular Degeneration: Retrospective Cohort Study

BACKGROUND

Exudative age-related macular degeneration (AMD), one of the leading causes of blindness, requires expensive drugs such as anti-vascular endothelial growth factor (VEGF) agents. The long-term regular use of effective but expensive drugs causes an economic burden for patients with exudative AMD. However, there are no studies on the long-term patient-centered economic burden of exudative AMD after reimbursement of anti-VEGFs.

OBJECTIVE

This study aimed to evaluate the patient-centered economic burden of exudative AMD for 2 years, including nonreimbursement and out-of-pocket costs, compared with nonexudative AMD using the Observational Medical Outcomes Partnership (OMOP) Common Data Model (CDM).

METHODS

This retrospective cohort study was conducted using the OMOP CDM, which included 2,006,478 patients who visited Seoul National University Bundang Hospital from June 2003 to July 2019. We defined the exudative AMD group as patients aged >50 years with a diagnosis of exudative AMD and a prescription for anti-VEGFs or verteporfin. The control group was defined as patients aged >50 years without a diagnosis of exudative AMD or a prescription for anti-VEGFs or verteporfin. To adjust for selection bias, controls were matched by propensity scores using regularized logistic regression with a Laplace prior. We measured any medical cost occurring in the hospital as the economic burden of exudative AMD during a 2-year follow-up period using 4 categories: total medical cost, reimbursement cost, nonreimbursement cost, and out-of-pocket cost. To estimate the average cost by adjusting the confounding variable and overcoming the positive skewness of costs, we used an exponential conditional model with a generalized linear model.

RESULTS

We identified 931 patients with exudative AMD and matched 783 (84.1%) with 2918 patients with nonexudative AMD. In the exponential conditional model, the total medical, reimbursement, nonreimbursement, and out-of-pocket incremental costs were estimated at US $3426, US $3130, US $366, and US $561, respectively, in the first year and US $1829, US $1461, US $373, and US $507, respectively, in the second year. All incremental costs in the exudative AMD group were 1.89 to 4.25 and 3.50 to 5.09 times higher in the first and second year, respectively, than those in the control group (P<.001 in all cases).

CONCLUSIONS

Exudative AMD had a significantly greater economic impact (P<.001) for 2 years on reimbursement, nonreimbursement, and out-of-pocket costs than nonexudative AMD after adjusting for baseline demographic and clinical characteristics using the OMOP CDM. Although economic policies could relieve the economic burden of patients with exudative AMD over time, the out-of-pocket cost of exudative AMD was still higher than that of nonexudative AMD for 2 years. Our findings support the need for expanding reimbursement strategies for patients with exudative AMD given the significant economic burden faced by patients with incurable and fatal diseases both in South Korea and worldwide.

Recent Developments in Gene Therapy for Neovascular Age-Related Macular Degeneration: A Review

Age-related macular degeneration (AMD) is a complex and multifactorial disease and a leading cause of irreversible blindness in the elderly population. The anti-vascular endothelial growth factor (anti-VEGF) therapy has revolutionized the management and prognosis of neovascular AMD (nAMD) and is currently the standard of care for this disease. However, patients are required to receive repeated injections, imposing substantial social and economic burdens. The implementation of gene therapy methods to achieve sustained delivery of various therapeutic proteins holds the promise of a single treatment that could ameliorate the treatment challenges associated with chronic intravitreal therapy, and potentially improve visual outcomes. Several early-phase trials are currently underway, evaluating the safety and efficacy of gene therapy for nAMD; however, areas of controversy persist, including the therapeutic target, route of administration, and potential safety issues. In this review, we assess the evolution of gene therapy for nAMD and summarize several preclinical and early-stage clinical trials, exploring challenges and future directions.

A review of emerging tyrosine kinase inhibitors as durable treatment of neovascular age-related macular degeneration

INTRODUCTION

Current treatment for age-related macular degeneration poses a large burden on patients and the inability of patients to adhere to this immense burden can lead to worse visual outcomes. Novel treatments have been proposed to extend treatment intervals and reduce visit burden.

AREAS COVERED

This review article summarizes phase I and phase II clinical trials of tyrosine kinase inhibitors as durable treatment options for patient with neovascular age-related macular degeneration.

EXPERT OPINION

Tyrosine kinase inhibitors have shown substantial promise in reducing treatment burden while maintaining visual acuity and anatomic outcomes with favorable safety profiles. Several platforms have shown positive outcomes in initial trials and are currently moving toward phase III clinical trials.

Preclinical evaluation of KH631, a novel rAAV8 gene therapy product for neovascular age-related macular degeneration

The upregulation of vascular endothelial growth factor (VEGF) is strongly associated with the development of choroidal neovascularization (CNV) in patients with neovascular age-related macular degeneration (nAMD). Currently, the standard treatment for nAMD involves frequent intravitreal injections of anti-VEGF agents, which inhibit the growth of new blood vessels and prevent leakage. However, this treatment regimen places a significant burden on patients, their families, and healthcare providers due to the need for repeated visits to the clinic for injections. Gene therapy, which enables the sustained expression of anti-VEGF proteins after a single injection, can dramatically reduce the treatment burden. KH631 is a recombinant adeno-associated virus 8 vector that encodes a human VEGF receptor fusion protein, and it is being developed as a long-term treatment for nAMD. In preclinical studies using non-human primates, subretinal administration of KH631 at a low dose of 3 × 108 vg/eye resulted in remarkable retention of the transgene product in the retina and prevented the formation and progression of grade IV CNV lesions. Furthermore, sustained transgene expression was observed for more than 96 weeks. These findings suggest that a single subretinal injection of KH631 has the potential to offer a one-time, low-dose treatment for nAMD patients.

Intravitreal implants manufactured by supercritical foaming for treating retinal diseases

Chronic retinal diseases, such as age-related macular degeneration (AMD), are a major cause of global visual impairment. However, current treatment methods involving repetitive intravitreal injections pose financial and health burdens for patients. The development of controlled drug release systems, particularly for biological drugs, is still an unmet need in prolonging drug release within the vitreous chamber. To address this, green supercritical carbon dioxide (scCO2) foaming technology was employed to manufacture porous poly(lactic-co-glycolic acid) (PLGA)-based intravitreal implants loaded with dexamethasone. The desired implant dimensions were achieved through 3D printing of customised moulds. By varying the depressurisation rates during the foaming process, implants with different porosities and dexamethasone release rates were successfully obtained. These implants demonstrated controlled drug release for up to four months, surpassing the performance of previously developed implants. In view of the positive results obtained, a pilot study was conducted using the monoclonal antibody bevacizumab to explore the feasibility of this technology for preparing intraocular implants loaded with biologic drug molecules. Overall, this study presents a greener and more sustainable alternative to conventional implant manufacturing techniques, particularly suited for drugs that are susceptible to degradation under harsh conditions.

27‑Gauge vitrectomy vs. 25‑gauge vitrectomy in the management of proliferative diabetic retinopathy with preoperative intravitreal injection of conbercept

Small-gauge vitrectomy has become popular due to its notable advantages, including less trauma, shortened convalescence and improved manoeuvrability. The aim of the present study was to compare the surgical outcomes of 27-gauge (27-G) vitrectomy with those of 25-gauge (25-G) vitrectomy in the management of proliferative diabetic retinopathy (PDR) with preoperative intravitreal injection of conbercept. The data of 48 consecutive patients with PDR (48 eyes) were retrospectively collected. The patients underwent conbercept intravitreal injection and pars plana vitrectomy with a 27-G group (23 eyes) or 25-G group (25 eyes) vitrectomy system. The operating time, suturing rate, endodiathermy rate, postoperative best-corrected visual acuity (BCVA), intraocular pressure (IOP) and complications were recorded. The mean postoperative BCVA at final follow-up was significantly improved compared with that at the baseline in both groups (P<0.001 for both). The differences in the mean BCVA changes between the two groups were not significant (P>0.99), and no differences were observed in the final central foveal thickness (P=0.51) between the two groups. The final IOP remained stable compared with that at the baseline in the 27-G group (P=0.36) and the 25-G group (P=0.05). The suturing rate was significantly decreased in the 27-G group compared with the 25-G group (P=0.04). There were no significant differences between the two groups in terms of the operating time (P=0.18), rate of endodiathermy use (P>0.99), iatrogenic retinal breaks (P=0.42) or postoperative recurrent vitreous haemorrhage (P>0.99). In addition, no case of ocular hypotony was observed in either group. In conclusion, 27-G vitrectomy was as efficient and safe as 25-G vitrectomy in the management of PDR in terms of operating time and complications. With reference to the literature, preoperative conbercept injection appears to assist in decreasing the incidence of intraoperative and postoperative complications.

Clinical efficacy and changes of serum VEGF-A, VEGF-B, and PLGF after conbercept treating neovascular age-related macular degeneration

AIM

To evaluate the clinical efficacy and systemic safety profile of conbercept in clinical practice on vascular endothelial growth factor (VEGF)-A, VEGF-B, and placental growth factor (PLGF) levels after intravitreal injections for the neovascular age-related macular degeneration (AMD).

METHODS

Thirty-five patients (35 eyes) with neovascular AMD received intravitreal injections of conbercept treatment with pro re nata protocol. Best-corrected visual acuity (BCVA) and central retinal thickness (CRT) were detected before the intravitreal injection and at 1, 3, and 12mo after conbercept treatment. The levels of serum VEGF-A, VEGF-B, and PLGF were measured by enzyme-linked immunosorbent assay before the injection and 1 and 12mo after conbercept treatments.

RESULTS

At baseline, the mean BCVA score was 39.89±14.64 letters. The mean BCVA scores were 51.03±15.78, 56.71±14.38, and 52.49±10.16 letters at 1, 3, and 12mo after conbercept treatment, and the BCVA improvements were all significant, respectively (P<0.05). At baseline, the mean CRT was 436.7±141.9 µm. At 1, 3, and 12mo after conbercept treatment, the mean CRT values were 335.1±147.8, 301.1±116.5, and 312.2±98.22 µm, and the CRT improvements were all significant, respectively (P<0.05). At baseline, 1 and 12mo after conbercept treatment, the mean levels of serum VEGF-A were 1013.8±454.3, 953.1±426.4, and 981.5±471.7 pg/mL, the mean levels of serum VEGF-B were 46.93±24.76, 42.99±19.16, and 45.32±18.76 pg/mL, the mean levels of serum PLGF at these points were 251.7±154.9, 241.3±166.7, and 245.6±147.2 pg/mL, respectively. Compared with the baseline, the levels of serum VEGF-A, VEGF-B, and PLGF did not significantly change at 1 and 12mo after conbercept treatment, respectively (P>0.05).

CONCLUSION

Conbercept intravitreal injection leads to BCVA and CRT improvement, however, it does not significantly affect systemic serum VEGF-A, VEGF-B, and PLGF levels at 1 and 12mo after intravitreal injection treating neovascular AMD.

Twenty Years of Anti-Vascular Endothelial Growth Factor Therapeutics in Neovascular Age-Related Macular Degeneration Treatment

Neovascular age-related macular degeneration (nAMD) is the primary disastrous retinal disease that leads to blindness in the elderly population. In the early 2000s, nAMD resulted in irreversible vision loss and blindness with no available treatment options. However, there have been breakthrough advances in the drug development of anti-angiogenic biological agents over the last two decades. The primary target molecule for treating nAMD is the vascular endothelial growth factor (VEGF), and there are currently several anti-VEGF drugs such as bevacizumab, ranibizumab, and aflibercept, which have made nAMD more manageable than before, thus preventing vision loss. Nevertheless, it should be noted that these anti-VEGF drugs for nAMD treatment are not effective in more than half of the patients, and even those who initially gain visual improvements lose their vision over time, along with potential deterioration in the geography of atrophy. As a result, there have been continuous endeavors to improve anti-VEGF agents through better efficacy, fewer doses, expanded intervals, and additional targets. This review describes past and current anti-VEGF therapeutics used to treat nAMD and outlines future directions to improve the effectiveness and safety of anti-VEGF agents.

Development of nucleic acid medicines based on chemical technology

Oligonucleotide-based therapeutics have attracted attention as an emerging modality that includes the modulation of genes and their binding proteins related to diseases, allowing us to take action on previously undruggable targets. Since the late 2010s, the number of oligonucleotide medicines approved for clinical uses has dramatically increased. Various chemistry-based technologies have been developed to improve the therapeutic properties of oligonucleotides, such as chemical modification, conjugation, and nanoparticle formation, which can increase nuclease resistance, enhance affinity and selectivity to target sites, suppress off-target effects, and improve pharmacokinetic properties. Similar strategies employing modified nucleobases and lipid nanoparticles have been used for developing coronavirus disease 2019 mRNA vaccines. In this review, we provide an overview of the development of chemistry-based technologies aimed at using nucleic acids for developing therapeutics over the past several decades, with a specific emphasis on the structural design and functionality of chemical modification strategies.

Biofunctionalization of 3D printed collagen with bevacizumab-loaded microparticles targeting pathological angiogenesis

Pathological angiogenesis is a crucial attribute of several chronic diseases such as cancer, age-related macular degeneration, and osteoarthritis (OA). In the case of OA, pathological angiogenesis mediated by the vascular endothelial growth factor (VEGF), among other factors, contributes to cartilage degeneration and to implants rejection. In line with this, the use of the anti-VEGF bevacizumab (BVZ) has been shown to prevent OA progression and support cartilage regeneration. The aim of this work was to functionalize a medical grade collagen with poly (lactic-co-glycolic acid) (PLGA) microparticles containing BVZ via three-dimensional (3D) printing to target pathological angiogenesis. First, the effect of several formulation parameters on the encapsulation and release of BVZ from PLGA microparticles was studied. Then, the anti-angiogenic activity of released BVZ was tested in a 3D cell model. The 3D printability of the microparticle-loaded collagen ink was tested by evaluating the shape fidelity of 3D printed structures. Results showed that the release and the encapsulation efficiency of BVZ could be tuned as a function of several formulation parameters. In addition, the released BVZ was observed to reduce vascularization by human umbilical vein endothelial cells. Finally, the collagen ink with embedded BVZ microparticles was successfully printed, leading to shape-stable meniscus-, nose- and auricle-like structures. Taken altogether, we defined the conditions for the successful combination of BVZ-loaded microparticles with the 3D printing of a medical grade collagen to target pathological angiogenesis.

Oxidative Stress and Antioxidants in Age-Related Macular Degeneration

Oxidative stress plays a crucial role in aging-related eye diseases, including age-related macular degeneration (AMD), cataracts, and glaucoma. With age, antioxidant reparative capacity decreases, and excess levels of reactive oxygen species produce oxidative damage in many ocular cell types underling age-related pathologies. In AMD, loss of central vision in the elderly is caused primarily by retinal pigment epithelium (RPE) dysfunction and degeneration and/or choroidal neovascularization that trigger malfunction and loss of photo-sensing photoreceptor cells. Along with various genetic and environmental factors that contribute to AMD, aging and age-related oxidative damage have critical involvement in AMD pathogenesis. To this end, dietary intake of antioxidants is a proven way to scavenge free radicals and to prevent or slow AMD progression. This review focuses on AMD and highlights the pathogenic role of oxidative stress in AMD from both clinical and experimental studies. The beneficial roles of antioxidants and dietary micronutrients in AMD are also summarized.

Antioxidative Role of Heterophagy, Autophagy, and Mitophagy in the Retina and Their Association with the Age-Related Macular Degeneration (AMD) Etiopathogenesis

Age-related macular degeneration (AMD), an oxidative stress-linked neurodegenerative disease, leads to irreversible damage of the central retina and severe visual impairment. Advanced age and the long-standing influence of oxidative stress and oxidative cellular damage play crucial roles in AMD etiopathogenesis. Many authors emphasize the role of heterophagy, autophagy, and mitophagy in maintaining homeostasis in the retina. Relevantly modifying the activity of both macroautophagy and mitophagy pathways represents one of the new therapeutic strategies in AMD. Our review provides an overview of the antioxidative roles of heterophagy, autophagy, and mitophagy and presents associations between dysregulations of these molecular mechanisms and AMD etiopathogenesis. The authors performed an extensive analysis of the literature, employing PubMed and Google Scholar, complying with the 2013-2023 period, and using the following keywords: age-related macular degeneration, RPE cells, reactive oxygen species, oxidative stress, heterophagy, autophagy, and mitophagy. Heterophagy, autophagy, and mitophagy play antioxidative roles in the retina; however, they become sluggish and dysregulated with age and contribute to AMD development and progression. In the retina, antioxidative roles also play in RPE cells, NFE2L2 and PGC-1α proteins, NFE2L2/PGC-1α/ARE signaling cascade, Nrf2 factor, p62/SQSTM1/Keap1-Nrf2/ARE pathway, circulating miRNAs, and Yttrium oxide nanoparticles performed experimentally in animal studies.

Aptamers Versus Vascular Endothelial Growth Factor (VEGF): A New Battle against Ovarian Cancer

Cancer is one of the diseases that causes a high mortality as it involves unregulated and abnormal cell growth proliferation that can manifest in any body region. One of the typical ovarian cancer symptoms is damage to the female reproductive system. The death rate can be reduced through early detection of the ovarian cancer. Promising probes that can detect ovarian cancer are suitable aptamers. Aptamers, i.e., so-called chemical antibodies, have a strong affinity for the target biomarker and can typically be identified starting from a random library of oligonucleotides. Compared with other probes, ovarian cancer targeting using aptamers has demonstrated superior detection effectiveness. Various aptamers have been selected to detect the ovarian tumor biomarker, vascular endothelial growth factor (VEGF). The present review highlights the development of particular aptamers that target VEGF and detect ovarian cancer at its earliest stages. The therapeutic efficacy of aptamers in ovarian cancer treatment is also discussed.

Pharmacokinetic and Pharmacodynamic Rationale for Extending VEGF Inhibition Increasing Intravitreal Aflibercept Dose

BACKGROUND

The effects of various dosages and treatment regimens on intravitreal aflibercept concentrations and the proportion of free vascular endothelial growth factor (VEGF) to total VEGF were evaluated using a drug and disease assessment model. The 8 mg dosage received specific attention.

METHODS

A time-dependent mathematical model was developed and implemented using Wolfram Mathematica software v12.0. This model was used to obtain drug concentrations after multiple doses of different aflibercept dosages (0.5 mg, 2 mg, and 8 mg) and to estimate the time-dependent intravitreal free VEGF percentage levels. A series of fixed treatment regimens were modeled and evaluated as potential clinical applications.

RESULTS

The simulation results indicate that 8 mg aflibercept administered at a range of treatment intervals (between 12 and 15 weeks) would allow for the proportion of free VEGF to remain below threshold levels. Our analysis indicates that these protocols maintain the ratio of free VEGF below 0.001%.

CONCLUSIONS

Fixed q12-q15 (every 12-15 weeks) 8 mg aflibercept regimens can produce adequate intravitreal VEGF inhibition.

The Role of Eosinophil-Derived Neurotoxin and Vascular Endothelial Growth Factor in the Pathogenesis of Eosinophilic Asthma

Asthma is a chronic complex pulmonary disease characterized by airway inflammation, remodeling, and hyperresponsiveness. Vascular endothelial growth factor (VEGF) and eosinophil-derived neurotoxin (EDN) are two significant mediators involved in the pathophysiology of asthma. In asthma, VEGF and EDN levels are elevated and correlate with disease severity and airway hyperresponsiveness. Diversity in VEGF polymorphisms results in the variability of responses to glucocorticosteroids and leukotriene antagonist treatment. Targeting VEGF and eosinophils is a promising therapeutic approach for asthma. We identified lichochalcone A, bevacizumab, azithromycin (AZT), vitamin D, diosmetin, epigallocatechin gallate, IGFBP-3, Neovastat (AE-941), endostatin, PEDF, and melatonin as putative add-on drugs in asthma with anti-VEGF properties. Further studies and clinical trials are needed to evaluate the efficacy of those drugs. AZT reduces the exacerbation rate and may be considered in adults with persistent symptomatic asthma. However, the long-term effects of AZT on community microbial resistance require further investigation. Vitamin D supplementation may enhance corticosteroid responsiveness. Herein, anti-eosinophil drugs are reviewed. Among them are, e.g., anti-IL-5 (mepolizumab, reslizumab, and benralizumab), anti-IL-13 (lebrikizumab and tralokinumab), anti-IL-4 and anti-IL-13 (dupilumab), and anti-IgE (omalizumab) drugs. EDN over peripheral blood eosinophil count is recommended to monitor the asthma control status and to assess the efficacy of anti-IL-5 therapy in asthma.

Faricimab for the Treatment of Diabetic Macular Edema and Neovascular Age-Related Macular Degeneration

Nowadays; intravitreal anti-vascular endothelial growth factor (VEGF) drugs are considered the first-line therapeutic strategy for treating macular exudative diseases; including wet age-related macular degeneration (w-AMD) and diabetic macular edema (DME). Despite the important clinical achievements obtained by anti-VEGF drugs in the management of w-AMD and DME; some limits still remain; including high treatment burden; the presence of unsatisfactory results in a certain percentage of patients and long-term visual acuity decline due to complications such as macular atrophy and fibrosis. Targeting the angiopoietin/Tie (Ang/Tie) pathway beyond the VEGF pathway may be a possible therapeutic strategy; which may has the potential to solve some of the previous mentioned challenges. Faricimab is a new; bispecific antibody targeting both VEGF-A and the Ang-Tie/pathway. It was approved by FDA and; more recently; by EMA for treating w-AMD and DME. Results from phase III trials TENAYA and LUCERNE (w-AMD) and RHINE and YOSEMITE (DME) have shown the potential of faricimab to maintain clinical efficacy with more prolonged treatment regimens compared to aflibercept (12 or 16 weeks) with a a good safety profile.

Nanofiber-coated implants: Development and safety after intravitreal application in rabbits

Intravitreal injections are the preferred choice for drug administration to the posterior segment of the eye. However, the required frequent injections may cause complications to the patient and low adherence to the treatment. Intravitreal implants are able to maintain therapeutic levels for a long period. Biodegradable nanofibers can modulate drug release and allow the incorporation of fragile bioactive drugs. Age-related macular degeneration is one of the world major causes of blindness and irreversible vision loss. It involves the interaction between VEGF and inflammatory cells. In this work we developed nanofiber-coated intravitreal implants containing dexamethasone and bevacizumab for simultaneously delivery of these drugs. The implant was successfully prepared and the efficiency of the coating process was confirmed by scanning electron microscopy. Around 68% of dexamethasone was released in 35 days and 88% of bevacizumab in 48hs. The formulation presented activity in the reduction of vessels and was safe to the retina. It was not observed any clinical or histopathological change, neither alteration in retina function or thickness by electroretinogram and optical coherence tomography during 28 days. The nanofiber-coated implants of dexamethasone and bevacizumab may be considered as a new delivery system that can be effective for the treatment of AMD.

Efficacy Evaluation of Tissue Plasminogen Activator with Anti-Vascular Endothelial Growth Factor Drugs for Submacular Hemorrhage Treatment: A Meta-Analysis

Submacular hemorrhage (SMH) is the accumulation of blood in the macular area that can severely damage the macular structure and visual function. Recently, the intraocular administration of tissue plasminogen activator (TPA) with anti-vascular endothelial growth factor (anti-VEGF) drugs was reported to have a positive effect on SMH. This meta-analysis aimed to explore the efficacy and safety of the drug combination. We systematically searched the Web of Science, MEDLINE, EMBASE, and Cochrane Library databases and screened relevant full-length literature reports. The quality of the reports was assessed by two independent reviewers. The best-corrected visual acuity (BCVA) and foveal thickness (FT) were considered the main indicators of efficacy. RevMan 5.4 software was used for this meta-analysis. Twelve studies were analyzed, and the results showed that BCVA at 1 month (p < 0.001), 3 months (p < 0.001), 6 months (p < 0.001), and the last follow-up (p < 0.001) was improved relative to the preoperative value. The postoperative FT was lower than the preoperative FT (p < 0.001). No significant difference in efficacy was observed between subretinal and intravitreal TPA injections (p = 0.37). TPA with anti-VEGF drugs is safe for SMH treatment and can significantly improve BCVA and reduce FT.

Evaluation of Multiple Machine Learning Models for Predicting Number of Anti-VEGF Injections in the Comparison of AMD Treatment Trials (CATT)

Purpose

To apply machine learning models for predicting the number of pro re nata (PRN) injections of antivascular endothelial growth factor (anti-VEGF) for neovascular age-related macular degeneration (nAMD) in two years in the Comparison of AMD (age-related macular degeneration) Treatments Trials.

Methods

The data from 493 eligible participants randomized to PRN treatment of ranibizumab or bevacizumab were used for training (n = 393) machine learning models including support-vector machine (SVM), random forest, and extreme gradient boosting (XGBoost) models. Model performances of prediction using clinical and image data from baseline, weeks 4, 8, and 12 were evaluated by the area under the receiver operating characteristic curve (AUC) for predicting few (≤8) or many (≥19) injections, by R2 and mean absolute error (MAE) for predicting the total number of injections in two years. The best model was selected for final validation on a test dataset (n = 100).

Results

Using training data up to week 12, the models achieved AUCs of 0.79-0.82 and 0.79-0.81 for predicting few and many injections, respectively, with R2 of 0.34-0.36 (MAE = 4.45-4.58 injections) for predicting total injections in two years from cross-validation. In final validation on the test dataset, the SVM model had AUCs of 0.77 and 0.82 for predicting few and many injections, respectively, with R2 of 0.44 (MAE = 3.92 injections). Important features included fluid in optical coherence tomography, lesion characteristics, and treatment trajectory in the first three months.

Conclusions

Machine learning models using loading dose phase data have the potential to predict two-year anti-VEGF demand for nAMD and quantify feature importance for these predictions.

Translational Relevance

Prediction of anti-VEGF injections using machine learning models from readily available data, after further validation on independent datasets, has the potential to help optimize treatment protocols and outcomes for nAMD patients in an individualized manner.

Dual-responsive nanoparticles loading bevacizumab and gefitinib for molecular targeted therapy against non-small cell lung cancer

The combination of vascular endothelial growth factor (VEGF) inhibitors and tyrosine kinase inhibitors (TKIs) is newly available for molecular targeted therapy against non-small cell lung cancer (NSCLC) in clinic. However, the therapeutic benefits remain unsatisfying due to the poor drug delivery to targets of interest. In this study, we developed bevacizumab-coated gefitinib-loaded nanoparticles (BCGN) with dual-responsive drug release for inhibiting tumor angiogenesis and phosphorylation of epidermal growth factor receptor (EGFR). Through an exogenous corona strategy, bevacizumab is easily coated on gefitinib-loaded nanoparticles via electrostatic interaction. After intravenous injection, BCGN are efficiently accumulated in NSCLC tumors as confirmed by dual-model imaging. Bevacizumab is released from BCGN upon oxidation in tumor microenvironment, whereas gefitinib is released after being internalized by tumor cells and disassembled in reduction cytoplasm. The dual-responsive release of bevacizumab and gefitinib significantly inhibits tumor growth in both A549 and HCC827 human NSCLC models. Our approach provides a promising strategy to improve combinational molecular targeted therapy of NSCLC with precisely controlled drug release.

ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR BIOSIMILARS IN OPHTHALMOLOGY

BACKGROUND/PURPOSE

Anti-vascular endothelial growth factor therapies have proven effective in treating retinal diseases but come with a high financial burden to the patient and health care system. Biosimilar drugs present an opportunity to decrease the cost of these important ophthalmic medications, and several ophthalmic biosimilars are expected to be approved and enter the market in the coming years. The objectives of this review are to educate ophthalmologists on the safety and efficacy of biosimilars in ophthalmology in the United States and European Union, review the biosimilar manufacturing and approval process, and describe the upcoming ophthalmic biosimilars.

RESULTS

Two ranibizumab biosimilars are currently approved in the United States and European Union. Additional ranibizumab biosimilars, as well as biosimilars for aflibercept and bevacizumab, are currently in clinical development.

CONCLUSION

Biosimilar use in ophthalmology is expected to grow with the patent expiration of two major anti-vascular endothelial growth factor drugs, ranibizumab and aflibercept, and the development of an ophthalmology-specific bevacizumab biosimilar. Financial savings from biosimilar use in ophthalmology have the potential to reduce economic burden, increase treatment adherence, and ultimately improve health outcomes.

A systematic comparison of anti-angiogenesis efficacy and cardiotoxicity of receptor tyrosine kinase inhibitors in zebrafish model

Pathological angiogenesis is fundamental to progression of cancerous tumors and blinding eye diseases. Anti-angiogenic receptor tyrosine kinase inhibitors (TKIs) are in broad use for the treatment of these diseases. With more and more TKIs available, it is a challenge to make an optimal choice. It remains unclear whether TKIs demonstrate similar anti-angiogenesis activities in different tissues. Many TKIs have shown varying degrees of toxic effects that should also be considered in clinical use. This study investigates the anti-angiogenic effects of 13 FDA-approved TKIs on the intersegmental vessels (ISVs), subintestinal vessels (SIVs) and retinal vasculature in zebrafish embryos. The results show that vascular endothelial growth factor receptor TKIs (VEGFR-TKIs) exhibit anti-angiogenic abilities similarly on ISVs and SIVs, and their efficacy is consistent with their IC₅₀ values against VEGFR2. In addition, VEGFR-TKIs selectively induces the apoptosis of endothelial cells in immature vessels. Among all TKIs tested, axitinib demonstrates a strong inhibition on retinal neovascularization at a low dose that do not strongly affect ISVs and SIVs, supporting its potential application for retinal diseases. Zebrafish embryos demonstrate cardiotoxicity after VEGFR-TKIs treatment, and ponatinib and sorafenib show a narrow therapeutic window, suggesting that these two drugs may need to be dosed more carefully in patients. We propose that zebrafish is an ideal model for studying in vivo antiangiogenic efficacy and cardiotoxicity of TKIs.

Antioxidant Properties of Cerium Oxide Nanoparticles Prevent Retinal Neovascular Alterations In Vitro and In Vivo

In this study, we investigated whether cerium oxide nanoparticles (CeO₂-NPs), a promising antioxidant nanomaterial, may contrast retinal vascular alterations induced by oxidative damage in vitro and in vivo. For the in vivo experiments, the light damage (LD) animal model of Age-Related Macular Degeneration (AMD) was used and the CeO₂-NPs were intravitreally injected. CeO₂-NPs significantly decreased vascular endothelial growth factor (VEGF) protein levels, reduced neovascularization in the deep retinal plexus, and inhibited choroidal sprouting into the photoreceptor layer. The in vitro experiments were performed on human retinal pigment epithelial (ARPE-19) cells challenged with H₂O₂; we demonstrated that CeO₂-NPs reverted H₂O₂-induced oxidative stress-dependent effects on this cell model. We further investigated the RPE-endothelial cells interaction under oxidative stress conditions in the presence or absence of CeO₂-NPs through two experimental paradigms: (i) treatment of human umbilical vein endothelial cells (HUVECs) with conditioned media from ARPE-19 cells, and (ii) coculture of ARPE-19 and HUVECs. In both experimental conditions, CeO₂-NPs were able to revert the detrimental effect of H₂O₂ on angiogenesis in vitro by realigning the level of tubule formation to that of the control. Altogether, our results indicate, for the first time, that CeO₂-NPs can counteract retinal neovascularization and may be a new therapeutic strategy for the treatment of wet AMD.

Biomarkers as Predictive Factors of Anti-VEGF Response

Age-related macular degeneration is the main cause of irreversible vision in developed countries, and intravitreal anti-vascular endothelial growth factor (anti-VEGF) injections are the current gold standard treatment today. Although anti-VEGF treatment results in important improvements in the course of this disease, there is a considerable number of patients not responding to the standardized protocols. The knowledge of how a patient will respond or how frequently retreatment might be required would be vital in planning treatment schedules, saving both resource utilization and financial costs, but today, there is not an ideal biomarker to use as a predictive response to ranibizumab therapy. Whole blood and blood mononuclear cells are the samples most studied; however, few reports are available on other important biofluid samples for studying this disease, such as aqueous humor. Moreover, the great majority of studies carried out to date were focused on the search for SNPs in genes related to AMD risk factors, but miRNAs, proteomic and metabolomics studies have rarely been conducted in anti-VEGF-treated samples. Here, we propose that genomic, proteomic and/or metabolomic markers could be used not alone but in combination with other methods, such as specific clinic characteristics, to identify patients with a poor response to anti-VEGF treatment to establish patient-specific treatment plans.

Anti-VEGF Drugs Dynamics: Relevance for Clinical Practice

Background: A drug and disease assessment model was used to evaluate the impact of different treatment regimens on intravitreal ranibizumab, bevacizumab, aflibercept, and brolucizumab concentrations and the proportion of free vascular endothelial growth factor (VEGF) to total VEGF. Methods: A time-dependent mathematical model using Wolfram Mathematica software was used. The pharmacokinetic and pharmacodynamic data for anti-VEGFs were obtained from published reports. The model simulated drug concentration after single and multiple doses of ranibizumab, bevacizumab, aflibercept, and brolucizumab, and it extrapolated time-dependent intraocular free VEGF proportion values. Various fixed treatment regimens (q4, q8, q10, q12) were simulated and evaluated as candidates for clinical utilization. Results: Our mathematical model shows good correlation between intraocular VEGF proportion values and clinical data. Simulations suggest that each anti-VEGF agent would allow for distinct treatment intervals to keep the proportion of free VEGF under threshold levels. Regimens scheduling q8 ranibizumab, q8 bevacizumab, q12 aflibercept, and q10 brolucizumab administration permit to maintain the proportion of unbound VEGF below 0.001%. Conclusions: Fixed q8 ranibizumab, q8 bevacizumab, q12 aflibercept, or q10 brolucizumab regimens may produce adequate intraocular VEGF inhibition.