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Jiang F, Lei C, Chen Y, Zhou N, Zhang M. The complement system and diabetic retinopathy. Surv Ophthalmol 2024; 69:575-584. [PMID: 38401574 DOI: 10.1016/j.survophthal.2024.02.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 02/18/2024] [Accepted: 02/19/2024] [Indexed: 02/26/2024]
Abstract
Diabetic retinopathy (DR) is one of the common microvascular complications of diabetes mellitus and is the main cause of visual impairment in diabetic patients. The pathogenesis of DR is still unclear. The complement system, as an important component of the innate immune system in addition to defending against the invasion of foreign microorganisms, is involved in the occurrence and development of DR through 3 widely recognized complement activation pathways, the complement regulatory system, and many other pathways. Molecules such as C3a, C5a, and membrane attacking complex, as important molecules of the complement system, are involved in the pathologenesus of DR, either through direct damaging effects or by activating cells (microglia, macroglia, etc.) in the retinal microenvironment to contribute to the pathological damage of DR indirectly. We review the integral association of the complement system and DR to further understand the pathogenesis of DR and possibly provide a new strategy for itstreatment.
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Affiliation(s)
- Feipeng Jiang
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China; Macular Disease Research Laboratory, West China Hospital, Sichuan University, China
| | - Chunyan Lei
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China; Macular Disease Research Laboratory, West China Hospital, Sichuan University, China
| | - Yingying Chen
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China; Macular Disease Research Laboratory, West China Hospital, Sichuan University, China
| | - Nenghua Zhou
- Key Laboratory of Drug Targeting and Drug Delivery System of Ministry of Education, West China School of Pharmacy, Sichuan University, Chengdu, China
| | - Meixia Zhang
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China; Macular Disease Research Laboratory, West China Hospital, Sichuan University, China.
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Csaky KG, Miller JML, Martin DF, Johnson MW. Drug Approval for the Treatment of Geographic Atrophy: How We Got Here and Where We Need to Go. Am J Ophthalmol 2024; 263:231-239. [PMID: 38387826 PMCID: PMC11162935 DOI: 10.1016/j.ajo.2024.02.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 01/22/2024] [Accepted: 02/12/2024] [Indexed: 02/24/2024]
Abstract
PURPOSE To discuss the clinical trial results leading to the US Food and Drug Administration (FDA) approval of anti-complement therapies for geographic atrophy (GA), perspectives on functional data from the GA clinical trials, and how lessons from the FDA approval may guide future directions for basic and clinical research in AMD. DESIGN Selected literature review with analysis and perspective METHODS: We performed a targeted review of publicly available data from the clinical trials of pegcetacoplan and avacincaptad for the treatment of GA, as well as scientific literature on the natural history of GA and the genetics and basic science of complement in AMD. RESULTS The approval of pegcetacoplan and avacincaptad was based on an anatomic endpoint of a reduction in the rate of GA expansion over time. However, functional data from 2 phase 3 clinical trials for each drug demonstrated no visual benefit to patients in the treatment groups. Review of the genetics of AMD and the basic science of the role for complement in AMD provides only modest support for targeting complement as treatment for GA expansion, and alternative molecular targets for GA treatment are therefore discussed. Reasons for the disconnect between anatomic and functional outcomes in the clinical trials of anti-complement therapies are discussed, providing insight to guide the configuration of future clinical studies for GA. CONCLUSION Although avacincaptad and pegcetacoplan are our first FDA-approved treatments for GA, results from the clinical trials failed to show any functional improvement after 1 and 2 years, respectively, calling into question whether the drugs represent a "clinically relevant outcome." To improve the chances of more impactful therapies in the future, we provide basic-science rationale for pursuing non-complement targets; emphasize the importance of ongoing clinical research that more closely pins anatomic features of GA to functional outcomes; and provide suggestions for clinical endpoints for future clinical trials on GA.
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Affiliation(s)
- Karl G Csaky
- From the Retina Foundation of the Southwest (K.G.C.), Dallas, Texas, USA.
| | - Jason M L Miller
- Kellogg Eye Center (J.M.L.M., M.W.J.), University of Michigan, Ann Arbor, Michigan, USA; Cellular and Molecular Biology Program (J.M.L.M.), University of Michigan, Ann Arbor, Michigan, USA
| | - Daniel F Martin
- Cole Eye Institute (D.F.M.), Cleveland Clinic, Cleveland Ohio, USA
| | - Mark W Johnson
- Kellogg Eye Center (J.M.L.M., M.W.J.), University of Michigan, Ann Arbor, Michigan, USA
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Wilke GA, Apte RS. Complement regulation in the eye: implications for age-related macular degeneration. J Clin Invest 2024; 134:e178296. [PMID: 38690727 PMCID: PMC11060743 DOI: 10.1172/jci178296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2024] Open
Abstract
Careful regulation of the complement system is critical for enabling complement proteins to titrate immune defense while also preventing collateral tissue damage from poorly controlled inflammation. In the eye, this balance between complement activity and inhibition is crucial, as a low level of basal complement activity is necessary to support ocular immune privilege, a prerequisite for maintaining vision. Dysregulated complement activation contributes to parainflammation, a low level of inflammation triggered by cellular damage that functions to reestablish homeostasis, or outright inflammation that disrupts the visual axis. Complement dysregulation has been implicated in many ocular diseases, including glaucoma, diabetic retinopathy, and age-related macular degeneration (AMD). In the last two decades, complement activity has been the focus of intense investigation in AMD pathogenesis, leading to the development of novel therapeutics for the treatment of atrophic AMD. This Review outlines recent advances and challenges, highlighting therapeutic approaches that have advanced to clinical trials, as well as providing a general overview of the complement system in the posterior segment of the eye and selected ocular diseases.
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Affiliation(s)
- Georgia A. Wilke
- John F. Hardesty, MD, Department of Ophthalmology and Visual Sciences
| | - Rajendra S. Apte
- John F. Hardesty, MD, Department of Ophthalmology and Visual Sciences
- Department of Medicine, and
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri, USA
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Kambulyan L, Chopikyan A, Iritsyan S, Mkhitaryan A, Hovakimyan A. The Role of Complement System's C3 and C4 Fractions in the Pathogenesis of Uveitis. Ocul Immunol Inflamm 2024:1-6. [PMID: 38588040 DOI: 10.1080/09273948.2024.2337838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Accepted: 03/27/2024] [Indexed: 04/10/2024]
Abstract
PURPOSE To study the role of the complement system's C3 and C4 fractions in the pathogenesis of different types of uveitis. METHODS A prospective case-control study. 118 patients were enrolled. The control group comprised 60 patients who were otherwise healthy people undergoing cataract or pterygium surgery, whereas the uveitis patients group consisted of 58 people. The levels of C3 and C4 fractions in the blood and in the aqueous humor for both groups were evaluated and compared. RESULTS No statistically significant differences were found in the levels of the C3 and C4 fractions in the blood between the groups. However, a statistically significant difference was observed in the levels of C3 and C4 in the aqueous humor between the case and control groups, as C3 and C4 fractions were not detected in the control group. The analysis of the mean gradient between the C4 levels in the blood samples and in the aqueous samples did not reveal a statistically significant difference between the case and control groups. However, upon performing an analogous mean gradient analysis of C3 levels, a statistically significant elevation in the value of the mean gradient was observed in the case group as compared to the control group. CONCLUSION Our findings are in line with our initial hypothesis, that the complement system's C3 and C4 fractions may have a role in the pathogenesis of uveitis.
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Affiliation(s)
| | - Armine Chopikyan
- Department of the Public Health and Healthcare Organization, Yerevan State Medical University, Yerevan, Armenia
| | - Sevan Iritsyan
- Head of Laboratory Service of Yerevan Medical Scientific Center, Yerevan, Armenia
| | - Armen Mkhitaryan
- HistoGen Practical Scientific Center of Pathology, Yerevan State Medical University, Yerevan, Armenia
| | - Anna Hovakimyan
- Head of Cornea-Uveitis Department at Malayan Ophthalmologic Center, Yerevan State Medical University, Yerevan, Armenia
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Somers FM, Malek G. Estrogen related receptor alpha: Potential modulator of age-related macular degeneration. Curr Opin Pharmacol 2024; 75:102439. [PMID: 38447458 PMCID: PMC10947805 DOI: 10.1016/j.coph.2024.102439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 01/26/2024] [Accepted: 01/28/2024] [Indexed: 03/08/2024]
Abstract
To develop effective therapies for complex blinding diseases such as age-related macular degeneration (AMD), identification of mechanisms involved in its initiation and progression is needed. The estrogen-related receptor alpha (ESRRA) is an orphan nuclear receptor that regulates several AMD-associated pathogenic pathways. However, it has not been investigated in detail in the ocular posterior pole during aging or in AMD. This review delves into the literature highlighting the significance of ESRRA as a molecular target that may be important in the pathobiology of AMD, and discusses data available supporting the targeting of this receptor signaling pathway as a therapeutic option for AMD.
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Affiliation(s)
| | - Goldis Malek
- Department of Ophthalmology, Duke University School of Medicine, Durham, NC, USA; Department of Pathology, Duke University School of Medicine, Durham, NC, USA.
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Hristodorov D, Lohoff T, Luneborg N, Mulder GJ, Clark SJ. Investing in vision: Innovation in retinal therapeutics and the influence on venture capital investment. Prog Retin Eye Res 2024; 99:101243. [PMID: 38218527 DOI: 10.1016/j.preteyeres.2024.101243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 01/06/2024] [Accepted: 01/08/2024] [Indexed: 01/15/2024]
Abstract
Since the groundbreaking approval of the first anti-VEGF therapy in 2004, the retinal therapeutics field has undergone a remarkable transformation, witnessing a surge in novel, disease-modifying therapeutics for a broad spectrum of retinal diseases, extending beyond exudative VEGF-driven conditions. The surge in scientific advancement and the pressing, unmet, medical need have captured the attention of venture capital investors, who have collectively invested close to $10 billion in research and development of new retinal therapeutics between 2004 and 2023. Notably, the field of exudative diseases has gradually shifted away from trying to outcompete anti-VEGF therapeutics towards lowering the overall treatment burden by reducing injection frequency. Simultaneously, a new era has emerged in the non-exudative field, targeting prevalent conditions like dry AMD and rare indications such as Retinitis pigmentosa. This has led to promising drug candidates in development, culminating in the landmark approval of Luxturna for a rare form of Retinitis pigmentosa. The validation of new mechanisms, such as the complement pathway in dry AMD has paved the way for the approvals of Syvovre (Apellis) and Izervay (Iveric/Astellas), marking the first two therapies for this condition. In this comprehensive review, we share our view on the cumulative lessons from the past two decades in developing retinal therapeutics, covering both positive achievements and challenges. We also contextualize the investments, strategic partnering deals, and acquisitions of biotech companies, pharmaceutical companies venture capital investors in retinal therapeutics, respectively. Finally, we provide an outlook and potentially a forward-looking roadmap on novel retinal therapeutics, highlighting the emergence of potential new intervention strategies, such as cell-based therapies, gene editing, and combination therapies. We conclude that upcoming developments have the potential to further stimulate venture capital investments, which ultimately could facilitate the development and delivery of new therapies to patients in need.
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Affiliation(s)
| | | | | | | | - Simon J Clark
- Institute for Ophthalmic Research, Department for Ophthalmology, University Medical Center, Eberhard Karls University of Tübingen, Tübingen, Germany; University Eye Clinic, University Hospital Tübingen, Tübingen, Germany; Lydia Becker Institute of Immunology and Inflammation, Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, UK
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