Targeting C3b/C4b and VEGF with a bispecific fusion protein optimized for neovascular age-related macular degeneration therapy

TLR4/TRIF/Caspase-8/Caspase-1 Pathway in Choroidal Endothelial Cells Promotes Choroidal Neovascularization

PURPOSE

The purpose of this study was to investigate the role and mechanism of caspase-8 in the development of choroidal neovascularization induced by age-related macular degeneration, with the aim of identifying a potential therapeutic target for neovascular age-related macular degeneration.

METHODS

Mouse models of laser photocoagulation-induced choroidal neovascularization and hypoxic human choroidal endothelial cells were utilized to examine the involvement of caspase-8 in choroidal neovascularization development. The toll-like receptor 4/TIR domain-containing adaptor molecule 1/caspase-8 pathway was explored in hypoxic human choroidal endothelial cells to elucidate its contribution to pathological angiogenesis. Various experimental techniques, including inhibition assays and immunoblotting analysis, were employed to assess the effects and mechanisms of caspase-8 activation.

RESULTS

Inhibition of caspase-8 demonstrated attenuated choroidal neovascularization development in mice subjected to laser photocoagulation. Activation of the toll-like receptor 4/TIR domain-containing adaptor molecule 1/caspase-8 pathway was observed in hypoxic human choroidal endothelial cells. Upon activation by the toll-like receptor 4/TIR domain-containing adaptor molecule 1 axis, caspase-8 directly cleaved caspase-1, leading to the cleavage of interleukin-1β and interleukin-18 by caspase-1. Consequently, activation of interleukin-1β and interleukin-18 through the toll-like receptor 4/TIR domain-containing adaptor molecule 1/caspase-8/caspase-1 pathway promoted the proliferative, migratory, and tube-forming abilities of hypoxic human choroidal endothelial cells.

CONCLUSION

The findings of this study indicate that caspase-8 plays a crucial role in promoting choroidal neovascularization by activating interleukin-1β and interleukin-18 through the toll-like receptor 4/TIR domain-containing adaptor molecule 1/caspase-8/caspase-1 pathway in choroidal endothelial cells. Therefore, targeting caspase-8 may hold promise as a therapeutic approach for neovascular age-related macular degeneration.

Aberrant Lipid Metabolism and Complement Activation in Age-Related Macular Degeneration

Age-related macular degeneration (AMD) stands as a leading cause of severe visual impairment and blindness among the elderly globally. As a multifactorial disease, AMD's pathogenesis is influenced by genetic, environmental, and age-related factors, with lipid metabolism abnormalities and complement system dysregulation playing critical roles. This review delves into recent advancements in understanding the intricate interaction between these two crucial pathways, highlighting their contribution to the disease's progression through chronic inflammation, drusen formation, and retinal pigment epithelium dysfunction. Importantly, emerging evidence points to dysregulated lipid profiles, particularly alterations in high-density lipoprotein levels, oxidized lipid deposits, and intracellular lipofuscin accumulation, as exacerbating factors that enhance complement activation and subsequently amplify tissue damage in AMD. Furthermore, genetic studies have revealed significant associations between AMD and specific genes involved in lipid transport and complement regulation, shedding light on disease susceptibility and underlying mechanisms. The review further explores the clinical implications of these findings, advocating for a novel therapeutic approach that integrates lipid metabolism modulators with complement inhibitors. By concurrently targeting these pathways, the dual-targeted approach holds promise in significantly improving outcomes for AMD patients, heralding a new horizon in AMD management and treatment.

Comprehensive assessment of the impact of intravitreal faricimab on retinal diseases: A systematic review, meta-analysis, and trial sequential analysis

BACKGROUND

Faricimab stands as the inaugural and sole bispecific antibody approved by the US Food and Drug Administration (FDA) for intravitreal injection. Nonetheless, the efficacy and safety of intravitreal faricimab remained uncertain.

OBJECTIVES

The purpose of this study was to evaluate faricimab.

METHODS

This systematic review and meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines (CRD42023398320). Five databases (Pubmed, Embase, Web of science, Cochrane Library, ClinicalTrials gov) were searched. We calculated pooled standard mean difference or odds ratio with 95 % confident interval under a random-effect model or fixed-effect model. Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) was employed to ascertain the reliability of the analyses. Trial sequential analysis was performed to gauge the statistical reliability of the data in the cumulative meta-analysis.

RESULTS

8 studies (3975 participants) were included. The use of faricimab was associated with central subfield thickness (CST) change, but no difference was found in other primary efficacy outcomes. Apart from that, a correlation was observed between the use of faricimab and the risk of vitreous floaters. Based on TSA, strong evidence indicates that compared to the control group, faricimab aided in reducing CST but increasing the risk of vitreous floaters.

CONCLUSIONS

In this study, a correlation existed between the use of faricimab and a reduction in CST, indicating a superior therapeutic effect. Moreover, participants treated with faricimab demonstrated a higher risk of vitreous floaters. More randomized controlled trials are essential to further explore the efficacy and safety of faricimab.

Complement Inhibitors for Geographic Atrophy in Age-Related Macular Degeneration-A Systematic Review

BACKGROUND/OBJECTIVES

Age-related macular degeneration (AMD) is one of the main causes of blindness and visual impairment worldwide. Intravitreal complement inhibitors are an emergent approach in the treatment of AMD, which have had encouraging results. This systematic review analyzes the outcomes and safety of complement inhibitor therapies for GA in AMD cases.

METHODS

A comprehensive search on the PubMed and Web of Science databases returned 18 studies involving various complement inhibitor agents, with a total of 4272 patients and a mean follow-up of 68.2 ± 20.4 weeks.

RESULTS

Most treated patients were white (96.8%) and female (55.8%), with a mean age of 78.3 ± 7.8 years and a mean GA area of 8.0 ± 3.9 mm2. There were no differences in visual function change between treated and control participants. The mean GA area change was 2.4 ± 0.7 mm2 in treated participants vs. 2.7 ± 0.8 mm2 in control groups (p < 0.001). The ocular and systemic side effects were similar to those of intravitreal anti-VEGF. A less-understood effect was that of the onset of choroidal neovascularization (CNV) in 1.1-13% of patients; this effect was found to be more frequent in patients with neovascular AMD in the fellow eye or nonexudative CNV in the study eye at baseline.

CONCLUSIONS

Complement inhibitors may represent a useful therapy for GA in AMD, but a personalized approach to patient selection is necessary to optimize the outcomes.

Stable inhibition of choroidal neovascularization by adeno-associated virus 2/8-vectored bispecific molecules

Neovascular age-related macular degeneration (nAMD) causes severe visual impairment. Pigment epithelium-derived factor (PEDF), soluble CD59 (sCD59), and soluble fms-like tyrosine kinase-1 (sFLT-1) are potential therapeutic agents for nAMD, which target angiogenesis and the complement system. Using the AAV2/8 vector, two bi-target gene therapy agents, AAV2/8-PEDF-P2A-sCD59 and AAV2/8-sFLT-1-P2A-sCD59, were generated, and their therapeutic efficacy was investigated in laser-induced choroidal neovascularization (CNV) and Vldlr-/- mouse models. After a single injection, AAV2/8-mediated gene expression was maintained at high levels in the retina for two months. Both AAV2/8-PEDF-P2A-sCD59 and AAV2/8-sFLT-1-P2A-sCD59 significantly reduced CNV development for an extended period without side effects and provided efficacy similar to two injections of current anti-vascular endothelial growth factor monotherapy. Mechanistically, these agents suppressed the extracellular signal-regulated kinase and nuclear factor-κB pathways, resulting in anti-angiogenic activity. This study demonstrated the safety and long-lasting effects of AAV2/8-PEDF-P2A-sCD59 and AAV2/8-sFLT-1-P2A-sCD59 in CNV treatment, providing a promising therapeutic strategy for nAMD.

Light-Activated Anti-Vascular Combination Therapy against Choroidal Neovascularization

Choroidal neovascularization (CNV) underlies the crux of many angiogenic eye disorders. Although medications that target vascular endothelial growth factor (VEGF) are approved for treating CNV, their effectiveness in destroying new blood vessels is limited, and invasive intravitreal administration is required. Additionally, other drugs that destroy established neovessels, such as combretastatin A-4, may have systemic side effects that limit their therapeutic benefits. To overcome these shortcomings, a two-pronged anti-vascular approach is presented for CNV treatment using a photoactivatable nanoparticle system that can release a VEGF receptor inhibitor and a vascular disrupting agent when irradiated with 690 nm light. The nanoparticles can be injected intravenously to enable anti-angiogenic and vascular disrupting combination therapy for CNV through light irradiation to the eyes. This approach can potentiate therapeutic effects while maintaining a favorable biosafety profile for choroidal vascular diseases.

Efficacy and Safety of Efdamrofusp Alfa versus Aflibercept in Participants with Neovascular Age-Related Macular Degeneration: A Randomized, Double-Masked, Active-Controlled, Noninferiority, Phase II Trial

PURPOSE

To evaluate efficacy and safety of efdamrofusp alfa compared with aflibercept in neovascular age-related macular degeneration (nAMD).

DESIGN

Randomized, double-masked, multicenter, active-controlled, noninferiority phase II study.

PARTICIPANTS

A total of 231 treatment-naive and previously treated participants with active choroidal neovascularization secondary to nAMD were enrolled.

METHODS

Eligible participants were randomized (1:1:1) to 2 mg efdamrofusp alfa, 4 mg efdamrofusp alfa, or 2 mg aflibercept groups. Participants in all groups received 3 initial monthly loading doses, followed by treatment every 8 weeks, with assessment every 4 weeks up to week 52.

MAIN OUTCOME MEASURES

The primary end point was the mean best-corrected visual acuity (BCVA) change from baseline to week 36. The prespecified noninferiority margin was set as -5 letters (80% confidence interval [CI]).

RESULTS

Each treatment group included 77 participants. The mean BCVA changes from baseline to week 36 for 2 mg efdamrofusp alfa, 4 mg efdamrofusp alfa and aflibercept groups were +10.6, +11.4, and +12.0 letters, respectively; least squares mean difference were -1.4 (80% CI: -3.5 to 0.7) between 2 mg efdamrofusp alfa and aflibercept, and -0.6 (80% CI: -2.7 to 1.6) between 4 mg efdamrofusp alfa and aflibercept. Mean central retinal thickness changes were consistent across groups. Adverse event rate was comparable among the groups.

CONCLUSIONS

Efdamrofusp alfa demonstrated noninferiority to aflibercept in BCVA improvement, accompanied by a similar safety profile.

FINANCIAL DISCLOSURE(S)

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

Natural killer cells promote neutrophil extracellular traps and restrain macular degeneration in mice

Neovascular age-related macular degeneration (nvAMD) is the leading cause of blindness in the elderly population. Although it is known that nvAMD is associated with focal inflammation, understanding of the precise immune components governing this process remains limited. Here, we identified natural killer (NK) cells as a prominent lymphocyte population infiltrating the perivascular space of choroidal neovascularization (CNV) lesions in patients with nvAMD and in mouse models. Olink proteomic analysis and single-cell RNA sequencing combined with knockout studies demonstrated the involvement of C-C chemokine receptor 5 (CCR5) in NK cell recruitment and extravasation at the CNV sites of mice. Depletion of NK cells or inhibition of activating receptor NK group 2, member D (NKG2D) inhibited the formation of neutrophil extracellular traps, increased vascular leakage, and exacerbated pathological angiogenesis, indicating that NK cells restrain pathogenesis in this mouse model. Age is the strongest risk factor for AMD, and we show that NK cells from aged human donors exhibited a less cytotoxic phenotype. NK cells from old mice exhibited compromised protective effects in the CNV mouse model. In addition, interleukin-2 complex-mediated expansion of NK cells improved CNV formation in mice. Collectively, our study highlights NK cells as a potential therapeutic target for patients with nvAMD.

Autophagy in dry AMD: A promising therapeutic strategy for retinal pigment epithelial cell damage

Dry age-related macular degeneration (AMD) is a prevalent clinical condition that leads to permanent damage to central vision and poses a significant threat to patients' visual health. Although the pathogenesis of dry AMD remains unclear, there is consensus on the role of retinal pigment epithelium (RPE) damage. Oxidative stress and chronic inflammation are major contributors to RPE cell damage, and the NOD-like receptor thermoprotein structural domain-associated protein 3 (NLRP3) inflammasome mediates the inflammatory response leading to apoptosis in RPE cells. Furthermore, lipofuscin accumulation results in oxidative stress, NLRP3 activation, and the development of vitelliform lesions, a hallmark of dry AMD, all of which may contribute to RPE dysfunction. The process of autophagy, involving the encapsulation, recognition, and transport of accumulated proteins and dead cells to the lysosome for degradation, is recognized as a significant pathway for cellular self-protection and homeostasis maintenance. Recently, RPE cell autophagy has been discovered to be closely linked to the development of macular degeneration, positioning autophagy as a cutting-edge research area in the realm of dry AMD. In this review, we present an overview of how lipofuscin, oxidative stress, and the NLRP3 inflammasome damage the RPE through their respective causal mechanisms. We summarized the connection between autophagy, oxidative stress, and NLRP3 inflammatory cytokines. Our findings suggest that targeting autophagy improves RPE function and sustains visual health, offering new perspectives for understanding the pathogenesis and clinical management of dry AMD.

Emerging Co-Assembled and Sustained Released Natural Medicinal Nanoparticles for Multitarget Therapy of Choroidal Neovascularization

Age-related macular degeneration (AMD) disease has become a worldwide senile disease, and frequent intravitreal injection of anti-vascular endothelial growth factor (anti-VEGF) is the mainstream treatment in the clinic, which is associated with sight-threatening complications. Herein, nintedanib, an inhibitor of angiogenesis, and lutein, a potent antioxidant, can co-assemble into nanoparticles through multiple noncovalent interactions. Interestingly, the co-assembled lutein/nintedanib nanoparticles (L/N NPs) exhibit significantly improved stability and achieve long-term sustained release of two drugs for at least two months in mice. Interestingly, in rabbit eyeball with a more complete barrier system, the L/N NPs still successfully distribute in the retina and choroid for a month. In the laser-induced mouse choroidal neovascularization model, the L/N NPs after a minimally invasive subconjunctival administration can successfully inhibit angiogenesis and achieve comparable and even better therapeutic results to that of standard intravitreal injection of anti-VEGF. Therefore, the subconjunctival injection of L/N NPs with long-term sustained drug release behavior represents a promising and innovative strategy for AMD treatment. Such minimally invasive administration together with the ability to effectively inhibit angiogenesis reduce inflammation and counteract oxidative stress and holds great potential for improving patient outcomes and quality of life in those suffering from this debilitating eye condition.

Identification of systemic biomarkers and potential drug targets for age-related macular degeneration

Purpose

Since age-related macular degeneration (AMD) is tightly associated with aging and cellular senescence, objective of this study was to investigate the association between plasma levels of senescence-related proteins (SRPs) and risk of AMD.

Design

The whole study was based on two-sample Mendelian randomization (MR) analysis.

Methods

For MR analysis, the primary approach for MR analysis was the inverse-variance weighted (IVW) method and the heterogeneity and pleiotropy of results were tested. The instrumental single-nucleotide polymorphisms (SNPs) associated with 110 SRPs were filtered and selected from a large genome-wide association study (GWAS) for plasma proteome involving 35,559 participants. The GWAS data of AMD was obtained from FinnGen consortium (6,157 AMD cases and 288,237 controls) and further validated by using data from UK Biobank consortium (3,553 AMD cases and 147,089 controls).

Results

The MR results at both discovery and validation stages supported the causality (IVW-P < 0.00045) between plasma levels of 4 SRPs (C3b, CTNNB1, CCL1, and CCL3L1) and the risk of AMD and supported potential causality (IVW-P < 0.05) between other 10 SRPs and risk of AMD. No heterogeneity or pleiotropy in these results was detected.

Conclusion

Our findings supported that high plasma levels of C3b, CTNNB1, CCL1, and CCL3L1 were associated with increased risk of AMD, thereby highlighting the role of systemic inflammation in AMD pathogenesis and providing the rationale for developing new preventative and therapeutic strategies.

AAV2-antiVEGFscFv gene therapy for retinal neovascularization

Retinal neovascularization (NV) may lead to irreversible vision impairment, the main treatment for which is the inhibition of vascular endothelial growth factor (VEGF). Existing drugs show limited clinical benefits because of their high prices and short half-lives, which increase the financial burden and medical risks to patients. Gene therapy on the basis of adeno-associated viruses is a promising approach to overcome these limitations because of the nonintegrative nature, low immunogenicity, and potential long-term gene expression of adeno-associated viruses. In this study, we constructed a novel recombinant adeno-associated virus with the single-chain fragment variable (scFv) fragment of the anti-VEGF antibody, AAV2-antiVEGFscFv, consisting of the VH and VL structural domains of IgG. AAV2-antiVEGFscFv effectively inhibited NV, retinal leakage, and retinal detachment in oxygen-induced retinopathy (OIR) mice, Tet/opsin/VEGF double-transgenic mice, and VEGF-induced rabbit NV models. AAV2-antiVEGFscFv also significantly suppressed VEGF-induced inflammation. Furthermore, we showed that AAV2-antiVEGFscFv could be sustainably expressed for a prolonged period and exhibited low immunotoxicity in vivo. This study indicates that AAV2-antiVEGFscFv could be a potential approach for NV treatment and provides strong support for preclinical research.

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.

Imaging Histology Correlations of Intraretinal Fluid in Neovascular Age-Related Macular Degeneration

Purpose

Fluid presence and dynamism is central to the diagnosis and management of neovascular age-related macular degeneration. On optical coherence tomography (OCT), some hyporeflective spaces arise through vascular permeability (exudation) and others arise through degeneration (transudation). Herein we determined whether the histological appearance of fluid manifested this heterogeneity.

Methods

Two eyes of a White woman in her 90s with anti-vascular endothelial growth factor treated bilateral type 3 neovascularization secondary to age-related macular degeneration were osmicated, prepared for submicrometer epoxy resin sections, and correlated to eye-tracked spectral domain OCT. Examples of intraretinal tissue fluid were sought among similarly prepared donor eyes with fibrovascular scars, in a web-based age-related macular degeneration histopathology resource. Fluid stain intensity was quantified in reference to Bruch's membrane and the empty glass slide.

Results

Exudative fluid by OCT was slightly reflective and dynamically responded to anti-vascular endothelial growth factor. On histology, this fluid stained moderately, possessed a smooth and homogenous texture, and contained blood cells and fibrin. Nonexudative fluid in degenerative cysts and in outer retinal tubulation was minimally reflective on OCT and did not respond to anti-vascular endothelial growth factor. By histology, this fluid stained lightly, possessed a finely granular texture, and contained mainly tissue debris. Quantification supported the qualitative impressions of fluid stain density. Cells containing retinal pigment epithelium organelles localized to both fluid types.

Conclusions

High-resolution histology of osmicated tissue can distinguish between exudative and nonexudative fluid, some of which is transudative.

Translational Relevance

OCT and histological features of different fluid types can inform clinical decision-making and assist in the interpretation of newly available automated fluid detection algorithms.

Macrophage Sult2b1 promotes pathological neovascularization in age-related macular degeneration

Disordered immune responses and cholesterol metabolism have been implicated in age-related macular degeneration (AMD), the leading cause of blindness in elderly individuals. SULT2B1, the key enzyme of sterol sulfonation, plays important roles in inflammation and cholesterol metabolism. However, the role and underlying mechanism of SULT2B1 in AMD have not been investigated thus far. Here, we report that SULT2B1 is specifically expressed in macrophages in choroidal neovascularization lesions. Sutl2b1 deficiency significantly reduced leakage areas and inhibited pathological angiogenesis by inhibiting M2 macrophage activation in vivo and in vitro. Mechanistically, loss of Sult2b1 activated LXRs and subsequently increased ABCA1 and ABCG1 (ABCA1/G1)-mediated cholesterol efflux from M2 macrophages. LXR inhibition (GSK2033 treatment) in Sult2b1 -/- macrophages reversed M2 polarization and decreased intracellular cholesterol capacity to promote pathological angiogenesis. In contrast to SULT2B1, STS, an enzyme of sterol desulfonation, protected against choroidal neovascularization development by activating LXR-ABCA1/G1 signalling to block M2 polarization. Collectively, these data reveal a cholesterol metabolism axis related to macrophage polarization in neovascular AMD.

Roles and mechanisms of long non-coding RNAs in age-related macular degeneration

Worldwide, age-related macular degeneration (AMD) is a multifactorial progressive fundus disorder that can cause vision impairment and severe central blindness in older adults. Currently, there are no approved prevention or treatment strategies for non-exudative AMD. While targeting VEGF is the main therapeutic approach to delay the degeneration process in exudative AMD, a significant number of patients show insensitivity or ineffectiveness to anti-VEGF therapy. Despite years of research, the exact mechanism underlying drusen formation and macular atrophy in AMD remains unknown. In the pathogenesis of AMD, lncRNAs play crucial roles, as discussed in this paper. This review focuses on the function of dysregulated lncRNAs and the mechanisms by which specific molecules target these lncRNAs in AMD. The analysis reveals that lncRNAs primarily regulate the progression of AMD by mediating apoptosis, epithelial-mesenchymal transition (EMT), dedifferentiation, and oxidative stress in choroidal vascular endothelial cells, retinal pigment epithelium (RPE) cells, and photoreceptors. Consequently, the regulation of apoptosis, dedifferentiation, EMT, and other processes by lncRNAs has emerged as a crucial focus in AMD research.These findings contribute to our understanding of the role of lncRNAs in AMD and their potential as valuable biomarkers. Furthermore, they highlight the need for further basic and clinical studies to explore the value of lncRNAs as biomarkers and potential therapeutic targets for AMD.

Chimpanzee adenovirus-mediated multiple gene therapy for age-related macular degeneration

Neovascular age-related macular degeneration AMD (nAMD) is characterized by choroidal neovascularization (CNV) and could lead to irreversible blindness. However, anti-vascular endothelial growth factor (VEGF) therapy has limited efficacy. Therefore, we generated a chimpanzee adenoviral vector (AdC68-PFC) containing three genes, pigment endothelial-derived factor (PEDF), soluble fms-like tyrosine kinase-1 (sFlt-1), and soluble forms of CD59 (sCD59), to treat nAMD. The results showed that AdC68-PFC mediated a strong onset of PEDF, sFlt-1, and sCD59 expression both in vivo and in vitro. AdC68-PFC showed preventive and therapeutic effects following intravitreal (IVT) injection in the laser-induced CNV model and very low-density lipoprotein receptor-deficient (Vldlr-/-) mouse model. In vitro assessment indicated that AdC68-PFC had a strong inhibitory effect on endothelial cells. Importantly, the safety test showed no evidence of in vivo toxicity of adenovirus in murine eyes. Our findings suggest that AdC68-PFC may be a long-acting and safe gene therapy vector for future nAMD treatments.

Thrombospondin-1 proteomimetic polymers exhibit anti-angiogenic activity in a neovascular age-related macular degeneration mouse model

Neovascular age-related macular degeneration (nAMD) is the leading cause of blindness in the developed world. Current therapy includes monthly intraocular injections of anti-VEGF antibodies, which are ineffective in up to one third of patients. Thrombospondin-1 (TSP1) inhibits angiogenesis via CD36 binding, and its down-regulated expression is negatively associated with the onset of nAMD. Here, we describe TSP1 mimetic protein-like polymers (TSP1 PLPs). TSP1 PLPs bind CD36 with high affinity, resist degradation, show prolonged intraocular half-lives (13.1 hours), have no toxicity at relevant concentrations in vivo (40 μM), and are more efficacious in ex vivo choroidal sprouting assays compared to the peptide sequence and Eylea (aflibercept), the current standard of care anti-VEGF treatment. Furthermore, PLPs exhibit superior in vivo efficacy in a mouse model for nAMD compared to control PLPs consisting of scrambled peptide sequences, using fluorescein angiography and immunofluorescence. Since TSP-1 inhibits angiogenesis by VEGF-dependent and independent mechanisms, TSP1 PLPs are a potential therapeutic for patients with anti-VEGF treatment-resistant nAMD.

Recent advances of smart materials for ocular drug delivery

Owing to the variety and complexity of ocular diseases and the natural ocular barriers, drug therapy for ocular diseases has significant limitations, such as poor drug targeting to the site of the disease, poor drug penetration, and short drug retention time in the vitreous body. With the development of biotechnology, biomedical materials have reached the "smart" stage. To date, despite their inability to overcome all the aforementioned drawbacks, a variety of smart materials have been widely tested to treat various ocular diseases. This review analyses the most recent developments in multiple smart materials (inorganic particles, polymeric particles, lipid-based particles, hydrogels, and devices) to treat common ocular diseases and discusses the future directions and perspectives regarding clinical translation issues. This review can help researchers rationally design more smart materials for specific ocular applications.

Serum Amyloid A 4 as a Common Marker of Persistent Inflammation in Patients with Neovascular Age-Related Macular Degeneration and Polypoidal Choroidal Vasculopathy

Background

Neovascular age-related macular degeneration (nAMD) and its subtype, polypoidal choroidal vasculopathy (PCV), are common choroidal vasculopathies. Although they share many common clinical manifestations and treatment strategies, a lack of comprehensive analysis of these conditions means that it is difficult for researchers to further explore the common pathomechanisms of nAMD and PCV. The aim of this study was to characterize aqueous humor (AH) proteome alterations and identify a novel biomarker related to both nAMD and PCV.

Methods

Liquid Chromatography with tandem mass spectrometry (LC-MS/MS) was adopted to analyze the AH proteomes of nAMD, PCV and controls. The target protein was validated using the enzyme-linked immunosorbent assay (ELISA) and subjected to receiver operating characteristic (ROC) curve analysis.

Results

A total of 737 different proteins were identified in all the groups, of which 544 were quantifiable. The bioinformatics analysis suggested that immune response activation is the essential event in both nAMD and PCV. Serum amyloid A (SAA) 4 is closely associated with a number of chronic inflammatory diseases, and it was enriched as the hub protein. ROC analysis showed that SAA4 could distinguish both nAMD and PCV from the controls.

Conclusion

This comprehensive study provides insights into, and furthers our understanding of, the pathological mechanism of nAMD and PCV. Additionally, the SAA4 level alteration may serve as a common biomarker of nAMD and PCV.

Diabetic retinopathy in China: Epidemiology, screening and treatment trends-A review

Diabetic retinopathy (DR) is the leading cause of vision impairment in the global working-age population. In China, with one-third of the world's diabetes population estimated at 141 million, the blindness prevalence due to DR has increased significantly. The country's geographic variations in socioeconomic status have led to prominent disparities in DR prevalence, screening and management. Reported risk factors for DR in China include the classic ones, such as long diabetes duration, hyperglycaemia, hypertension and rural habitats. There is no national-level DR screening programme in China, but significant pilot efforts are underway for screening innovations. Novel agents with longer durations, noninvasive delivery or multi-target are undergoing clinical trials in China. Although optimised medical insurance policies have enhanced accessibility for expensive therapies like anti-VEGF drugs, further efforts in DR prevention and management in China are required to establish nationwide cost-effective screening programmes, including telemedicine and AI-based solutions, and to improve insurance coverage for related out-of-pocket expenses.

Rethinking the potential and necessity of drug delivery systems in neovascular age-related macular degeneration therapy

Age-related macular degeneration (AMD) is the predominant threat to human vision and ultimately results in blindness. With the increase in the aging population, it has become a more crucial issue to human health. AMD is a multifactorial disease with the unique feature of uncontrollable angiogenesis during initiation and progression. Although increasing evidence indicates that AMD is largely hereditary, the predominant efficient treatment is antiangiogenesis, which mainly involves VEGF and HIF-α as therapeutic targets. The repeated administration of this treatment over the long term, generally through intravitreal injection, has called for the introduction of long-term drug delivery systems, which are expected to be achieved by biomaterials. However, the clinical results of the port delivery system indicate that the optimization of medical devices toward prolonging the activities of therapeutic biologics in AMD therapy seems more promising. These results indicate that we should rethink the possibility and potential of biomaterials as drug delivery systems in achieving long-term, sustained inhibition of angiogenesis in AMD therapy. In this review, the etiology, categorization, risk factors, pathogenesis, and current clinical treatments of AMD are briefly introduced. Next, the development status of long-term drug delivery systems is discussed, and the drawbacks and shortages of these systems are emphasized. By comprehensively considering the pathological aspect and the recent application of drug delivery systems in AMD therapy, we hope to find a better solution for the further development of long-term therapeutic strategies for AMD.

Ocular Delivery of Therapeutic Agents by Cell-Penetrating Peptides

Cell-penetrating peptides (CPPs) are short peptides with the ability to translocate through the cell membrane to facilitate their cellular uptake. CPPs can be used as drug-delivery systems for molecules that are difficult to uptake. Ocular drug delivery is challenging due to the structural and physiological complexity of the eye. CPPs may be tailored to overcome this challenge, facilitating cellular uptake and delivery to the targeted area. Retinal diseases occur at the posterior pole of the eye; thus, intravitreal injections are needed to deliver drugs at an effective concentration in situ. However, frequent injections have risks of causing vision-threatening complications. Recent investigations have focused on developing long-acting drugs and drug delivery systems to reduce the frequency of injections. In fact, conjugation with CPP could deliver FDA-approved drugs to the back of the eye, as seen by topical application in animal models. This review summarizes recent advances in CPPs, protein/peptide-based drugs for eye diseases, and the use of CPPs for drug delivery based on systematic searches in PubMed and clinical trials. We highlight targeted therapies and explore the potential of CPPs and peptide-based drugs for eye diseases.

A Novel Bispecific Fusion Protein Targeting C3b/C4b and VEGF in Patients With nAMD: A Randomized, Open-Label, Phase 1b Study

PURPOSE

To evaluate the safety, tolerability, and efficacy of efdamrofusp alfa in patients with neovascular age-related macular degeneration (nAMD).

DESIGN

Prospective randomized, open-label, multiple ascending-dose, phase 1b study.

METHODS

Patients aged 50 years or older with active choroid neovascularization (CNV) secondary to nAMD were screened from 2 hospitals in 2 provinces in China. The first 9 patients were randomized 2:1 to intravitreally receive efdamrofusp alfa 2 mg at weeks 0, 4, and 8 or aflibercept 2 mg at weeks 0, 4, 8, and 16. After the dose-limiting toxicity assessment, 9 additional patients were randomized 2:1 to intravitreally receive efdamrofusp alfa 4 mg at weeks 0, 4, and 8 or aflibercept 2 mg at weeks 0, 4, 8, and 16. All patients were followed until week 20. Primary outcomes were safety and tolerability of efdamrofusp alfa. Secondary outcomes included changes from baseline in best-corrected visual acuity (BCVA), central subfield thickness (CST) as measured by spectral domain optical coherence tomography (SD-OCT), and CNV area as measured by fluorescein angiography (FA).

RESULTS

A total of 18 patients were enrolled. Six each of them received efdamrofusp alfa 2 mg, efdamrofusp alfa 4 mg, or aflibercept 2 mg, respectively. No dose-limiting toxicity was reported, and all patients completed the study. No ocular serious adverse events were reported. All ocular treatment-emergent adverse events were intravitreal injection related and were mild or moderate in severity. At week 20, mean changes from baseline in BCVA were 5.64 ± 3.56, 8.93 ± 3.59, and 7.92 ± 3.55 letters for patients receiving efdamrofusp alfa 2 mg, efdamrofusp alfa 4 mg and aflibercept 2 mg, respectively. Meanwhile, CST and CNV area reductions indicative of anatomic improvement were observed in the majority of the patients receiving both doses of efdamrofusp alfa and aflibercept.

CONCLUSIONS

Intravitreal efdamrofusp alfa dosed up to 4 mg every 4 weeks was well tolerated in nAMD patients with similar vision acuity and anatomic improvements.

Retinal fluid is associated with cytokines of aqueous humor in age-related macular degeneration using automatic 3-dimensional quantification

Background: To explain the biological role of cytokines in the eye and the possible role of cytokines in the pathogenesis of neovascular age-related macular degeneration (nAMD) by comparing the correlation between cytokine of aqueous humor concentration and optical coherence tomography (OCT) retinal fluid. Methods: Spectral-domain OCT (SD-OCT) images and aqueous humor samples were collected from 20 nAMD patient's three clinical visits. Retinal fluid volume in OCT was automatically quantified using deep learning--Deeplabv3+. Eighteen cytokines were detected in aqueous humor using the Luminex technology. OCT fluid volume measurements were correlated with changes in aqueous humor cytokine levels using Pearson's correlation coefficient (PCC). Results: The patients with intraretinal fluid (IRF) showed significantly lower levels of cytokines, such as C-X-C motif chemokine ligand 2 (CXCL2) (p = 0.03) and CXCL11 (p = 0.009), compared with the patients without IRF. And the IRF volume was negatively correlated with CXCL2 (r = -0.407, p = 0.048) and CXCL11 (r = -0.410, p = 0.046) concentration in the patients with IRF. Meanwhile, the subretinal fluid (SRF) volume was positively correlated with vascular endothelial growth factor (VEGF) concentration (r = 0.299, p = 0.027) and negatively correlated with interleukin (IL)-36β concentration (r = -0.295, p = 0.029) in the patients with SRF. Conclusion: Decreased level of VEGF was associated with decreased OCT-based retinal fluid volume in nAMD patients, while increased levels of CXCL2, CXCL11, and IL-36β were associated with decreased OCT-based retinal fluid volume in nAMD patients, which may suggest a role for inflammatory cytokines in retinal morphological changes and pathogenesis of nAMD patients.

Retinal and Choroidal Neovascularization Antivascular Endothelial Growth Factor Treatments: The Role of Gene Therapy

Neovascularization in ocular vessels causes a major disease burden. The most common causes of choroidal neovascularization (CNV) are age-related macular degeneration and diabetic retinopathy, which are the leading causes of irreversible vision loss in the adult population. Vascular endothelial growth factor (VEGF) is critical for the formation of new vessels and is the main regulator in ocular angiogenesis and vascular permeability through its receptors. Laser therapy and antiangiogenic factors have been used for CNV treatment. Bevacizumab, ranibizumab, and aflibercept are commonly used anti-VEGF agents; however, high costs and the need for frequent intraocular injections are major drawbacks of anti-VEGF drugs. Gene therapy, given the potency of one-time treatment and no need for frequent injections offers the real possibility of such a lasting treatment, with fewer adverse effects and higher patient quality of life. Herein, we reviewed the role of gene therapy in the CNV treatment. In addition, we discuss the advantages and challenges of current treatments compared with gene therapy.