Update on intravitreal anti-tumor necrosis factor alpha therapies for ocular disorders

Intravitreal Infliximab for the Treatment of Proliferative Vitreoretinopathy (FIXER): A Randomized Controlled Phase II Trial

OBJECTIVE

To study the safety and efficacy of intravitreal infliximab administered at the conclusion of pars plana vitrectomy (PPV) in the treatment of proliferative vitreoretinopathy (PVR) associated with rhegmatogenous retinal detachment (RRD).

DESIGN

Randomized controlled phase II clinical trial.

SUBJECTS

Patients with primary RRD and grade C PVR, according to the updated Retina Society Classification.

METHODS

Sixty-six patients were randomized in a 1:1 ratio to undergo PPV and silicone oil (SO) injection with or without intravitreal injection of 1 mg/0.05 mL of infliximab in the air-filled globe before SO injection at PPV conclusion. Surgeons were masked to treatment allocation until PPV conclusion.

MAIN OUTCOME MEASURES

The primary outcome measure was anatomic success (defined as complete retinal reattachment without a tamponade at 6 months post SO removal). Secondary outcome measures were final best-corrected visual acuity (BCVA), single-operation success rate (SOSR), rate of recurrent detachment, central macular thickness (CMT) by macular OCT, macular function by multifocal electroretinogram, and macular vascular density (VD) by OCT angiography.

RESULTS

Sixty eyes of 60 patients, 30 eyes in each group, completed the study. At baseline, there were no differences regarding age, gender, history of trauma, lens status, duration of RRD, BCVA, intraocular pressure (IOP), intraocular inflammation (IOI), detachment extent in clock hours, number/size of breaks, presence of vitreous hemorrhage, axial length, or grade/extent of PVR between both groups. For the outcome measures, 30 eyes in the infliximab group achieved anatomic success vs. 29 eyes in the control group. The SOSR was higher in the infliximab group (26) vs. the control (23), but this was not statistically significant (P = 0.317). Final logarithm of the minimum angle of resolution BCVA was better in the infliximab group (mean, 0.96; standard deviation [SD], 0.4; Snellen equivalent ≈ 20/180) vs. the control (mean, 1.14; SD, 0.4); Snellen equivalent ≈ 20/280; P = 0.044). There were no differences regarding IOP, IOI, time of SO removal, macular function, CMT, or VD.

CONCLUSIONS

Pars plana vitrectomy with SO tamponade with or without intravitreal infliximab is effective in treating PVR-associated RRD. Infliximab may be associated with modest improvement in final visual outcomes but not anatomic outcomes.

FINANCIAL DISCLOSURE(S)

The authors have no proprietary or commercial interest in any materials discussed in this article.

Challenges for further successful development of tumor necrosis factor targeting therapies for uveitis

INTRODUCTION

Uveitis is a heterogeneous group of ocular conditions characterized by inflammation of the uveal tract and is one of the leading causes of vision impairment. In developed countries, noninfectious uveitis (NIU) represents most cases and is challenging to treat due to its severity, chronicity, and high recurrence rates. The advent of anti-tumor necrosis factor-α (anti-TNF-α) agents have dramatically improved outcomes and changed treatment paradigms in NIU.

AREAS COVERED

The index article summarizes the present experience of anti-TNF-α agents in NIU pharmacotherapy and highlights the barriers to further research and development of anti-TNF-α agents for uveitis. Common challenges faced in NIU clinical drugs trials, specific difficulties in anti-TNF-α drug development, and promising competitor drug candidates are discussed and evaluated.

EXPERT OPINION

Anti-TNF-α agents have revolutionized NIU pharmacotherapy and greatly improved outcomes with good safety profiles. The great success of systemic infliximab and adalimumab in NIU treatment has resulted in little impetus for further development of this class of medication. Attempts have been made to deliver anti-TNF-α agents intravitreally but that has not been successful thus far. With expiring patents, competition from biosimilars and newer, novel molecules, it may not be viable to continue pursuing anti-TNF-α drug development.

Immunology of Retinitis Pigmentosa and Gene Therapy-Associated Uveitis

The underlying immune state of inherited retinal degenerations (IRDs) and retinitis pigmentosa (RP) has been an emerging area of interest, wherein the consequences have never been greater given the widespread recognition of gene therapy-associated uveitis (GTU) in gene therapy clinical trials. Whereas some evidence suggests that the adaptive immune system may play a role, the majority of studies indicate that the innate immune system is likely the primary driver of neuroinflammation in RP. During retinal degeneration, discrete mechanisms activate resident microglia and promote infiltrating macrophages that can either be protective or detrimental to photoreceptor cell death. This persistent stimulation of innate immunity, overlaid by the introduction of viral antigens as part of gene therapy, has the potential to trigger a complex microglia/macrophage-driven proinflammatory state. A better understanding of the immune pathophysiology in IRD and GTU will be necessary to improve the success of developing novel treatments for IRDs.

Effect of adalimumab on experimental corneal neovascularization model

PURPOSE

To evaluate the efficacy of adalimumab (ADA) on inhibition of experimental corneal neovascularization (CNV) and compare the outcomes with bevacizumab (BEVA).

METHODS

Twenty-four female Winstar rats (48 eyes) were used. Silver/Potassium Nitrate sticks were used for creating CNV. Forty-eight eyes of the rats were separated into 6 groups. The eyes which only NaCl was injected subconjunctivally (SC) formed Group-1. The eyes which CNV was created and NaCl, BEVA (2.5 mg/0.05 mL), ADA (2.5 mg/0.05 mL), respectively, were injected SC formed group-2, 3 and 4. The eyes which only BEVA and ADA, respectively, were injected SC formed group-5 and 6. Five days later the animals were sacrificed. Hematoxylin and eosin staining, Masson trichrome staining, Vascular endothelial growth factor (VEGF), and Platelet-derived growth factor (PDGF) antibodies were performed.

RESULTS

Histochemical results showed that there was no histopathological finding in group-1, 5, and 6. Collagen fiber irregularity was observed in group-2 and there was a significant improvement in collagen fiber irregularity in group-3 and 4. Collagen fiber proliferation was higher in group-2 than in group-3 and 4. VEGF and PDGF stainings were not observed in group-1, 5, and 6. VEGF and PDGF stainings were observed in group-2 and significantly decreased in group-3 and 4 compared to group-2. ADA was found to be superior to BEVA in terms of decreasing VEGF staining.

CONCLUSION

Both BEVA and ADA were effective in inhibiting CNV. Subconjunctival ADA seems to be more effective than BEVA in terms of inhibiting VEGF expression. Further experimental studies about ADA and BEVA are needed.

Informed consent and biological agents in rheumatology and internal medicine

BACKGROUND

The need for highly effective therapies in rheumatologic diseases has led to the widespread and growing use of a heterogeneous class of molecules called biological agents. The increasing experience with biological agents has raised concerns about safety and efficacy issues that need to be discussed in the informed consent acquisition process.

METHODS

The authors performed a review of the literature on biological agents focusing on their most important characteristics concerning the informed consent procedures.

RESULTS

No studies specifically addressed the issue of informed consent in patients receiving biological agents. Several studies reported data about off-label use of biological agents usually with no obvious attention to informed consent shortcomings.

CONCLUSION

The reported association between biological agents and serious infections or malignancies, including reactivation of latent tuberculosis, needs specific disclosure in informed consent acquisition, together with information about the possible efficacy in clinical contexts often characterized by resistance to previous treatments. Ethical and clinical issues bound to the need for experimenting with new agents with potentially serious adverse effects deserve specific attention. Studies aimed at evaluating mental capacity to consent in subjects receiving biological agents are required.

Histological Effects of Intravitreal Injection of Antifungal Agents in New Zealand White Rabbits: An Electron Microscopic and Immunohistochemical Study

Fungal endophthalmitis is a serious and vision-threatening infection which requires an immediate and effective treatment approach. Our research aims to elucidate the histological effects of the intravitreal injection of the maximum safe dosage of voriconazole and micafungin on retina. Six albino New Zealand White Rabbits were used. In experimental animals, a solution of voriconazole (Group V) or micafungin (Group M) was intravitreally injected in the right eye, while in control animals, balanced salt solution was intravitreally injected in the left eye (Group C). Euthanasia was performed ten days post injection and the retina was removed and prepared for histological examination with a light and electron microscope. Eosin-hematoxylin staining did not reveal any pathological changes in any of the samples examined. The immunohistochemical staining for Tumor Necrosis Factor alpha (TNF-a) marker was detected as negative in all samples, while Interleukin 6 (IL-6) marker was detected as mild only in the group injected with voriconazole. Electron microscopy revealed several ultrastructural alterations in retinal layers in both groups of experimental animals. Histological retinal lesions, revealed with electron microscopy in the present investigation, raises the question of the safe usage of these antifungal agents in the treatment of fungal intraocular infections in the future.

An association of neovascular age-related macular degeneration with polymorphisms of CFH, ARMS2, HTRA1 and C3 genes in Czech population

PURPOSE

We investigated associations between neovascular age-related macular degeneration (AMD) and rs10490924 polymorphism of ARMS2 gene (age-related maculopathy susceptibility 2), rs1061170 polymorphism of gene for complement factor H (CFH), rs2230199 polymorphism of gene for complement component C3 and rs11200638 polymorphism of gene for serine protease high-temperature requirement A1 (HTRA1) in the Czech population.

METHODS

We analysed samples of DNA from 307 patients diagnosed with neovascular form of late AMD (average age: 73.7 ± 7.7 years) and 191 control subjects, recruited from patients awaiting cataract surgery (average age, 73.6 ± 8.7 years).

RESULTS

HTRA1, CFH and ARMS2 genes polymorphisms were found to be related to neovascular AMD in the Czech population. All analysed polymorphisms were statistically significantly associated with neovascular AMD, with stronger associations in females than in males. In whole group, CC genotype of CFH gene polymorphism, TT genotype of ARMS2 gene polymorphism and AA genotype of HTRA1 gene polymorphism showed the greatest risk for neovascular AMD with odds ratios equal to 8.43, 10.07, 9.83, respectively (p < 0.0001). Only CG polymorphism of C3 gene showed statistically significant risk for neovascular AMD. In addition, we observed an association between waist circumference and neovascular AMD in both sexes, which further suggests the significance of excessive abdominal fat as a risk factor of AMD. We found a statistically significant association between polymorphisms in HTRA1, CFH and ARMS2 genes and neovascular AMS in the Czech population. The association was stronger in females than in males.

CONCLUSION

We demonstrated a relationship between neovascular AMD and genes for HTRA1, CFH, ARMS2 and C3 in Czech population. To our knowledge, the relationship between these polymorphisms and neovascular AMD in Czech population has never been investigated before.

Ocular toxicity of intravitreal golimumab in a rabbit model

Background/aim

To investigate the effect of intravitreal golimumab on rabbit retina histopathology.

Materials and methods

Sixteen albino New Zealand rabbits were divided into three groups. The right eye of each rabbit in groups I, II, and III received a single intravitreal injection of 5 mg/0.05 mL (6 eyes), 10 mg/0.1 mL (6 eyes), or 20 mg/0.2 mL (4 eyes) golimumab, while left eyes served as controls with the same volume of a balanced salt solution injection. All animals were examined using slit-lamp biomicroscopy and indirect ophthalmoscopy before and after intravitreal injection and at days 1 and 7. Animals were euthanized on day 7 and the eyes were enucleated for immunohistochemistry evaluation and electron microscopic examination of the retinas.

Results

For groups I, II, and III, the number of cells in the outer nuclear layer and the inner nuclear layer was decreased compared to those in the control groups. In group I, the percentage of caspase-3 staining of the outer nuclear layer was significantly higher than that in the control. For groups II and III, TUNEL and caspase-3 staining percentages in the outer and inner nuclear layers were found to be significantly higher than those for the control groups. In the ganglion cell layer, for groups I, II, and III, neither TUNEL nor caspase-3 staining percentages showed any significant difference between two groups. No significant dose-dependent relationship was found for increasing doses of golimumab in all layers. Myelin figures and karyorrhexis in the photoreceptor cells were prominent in electron microscopy of the golimumab-injected eyes.

Conclusion

Golimumab caused apoptosis in both photoreceptors and bipolar cells of the rabbit retina. Potential retinal toxicity of intravitreal golimumab should be considered if an intravitreal administration is planned.

[Pharmacological treatment strategies and surgical options for uveitis]

BACKGROUND

Modern treatment of uveitis aims at a complete control of inflammatory activity, preservation of visual function and the prevention of secondary organ damage as a consequence of the underlying inflammatory disease and its treatment.

OBJECTIVE

This article gives an update about the strategies of pharmacological and surgical options for uveitis.

MATERIAL AND METHODS

The outcomes reported here are based on a PubMed search using the terms <"uveitis" AND "therapy"> and <"uveitis" AND "surgery" OR "surgical treatment">. All prospective studies and case series with more than 20 cases as well as review articles from the last 5 years along with cited cross-references were evaluated.

RESULTS

Local and systemic corticosteroids form the foundation of treatment after exclusion of an infectious etiology. If uveitis activity is not controlled within 6 weeks or if the daily corticosteroid dosage is unacceptably high, a treatment escalation using immunomodulatory drugs is required. If a complete control of inflammatory activity is not achieved, in a third phase treatment is supplemented by antibody-based treatment or cytokines, so-called biologics, with the aim of complete long-term freedom from disease without local or systemic steroid treatment. This target is achieved in 65-80% and guarantees long-term functional stability and anatomical integrity. Early treatment escalation in cases of persisting or recurrent activity as a rule prevents new secondary organ damage. Surgical options are utilized for diagnostic purposes, the administration of intravitreal drugs and for treatment of secondary complications.

CONCLUSION

Just like the majority of immunological diseases, uveitis is a chronic disease requiring long-term and possibly lifelong treatment and remission (absence of inflammation without treatment) is achieved in only <20%. Surgical interventions can be performed with a good prognosis, if the optic nerve head and macula are not involved. They have a substantially lower complication rate when freedom from symptoms exists preoperatively for at least 3 months.

Uveitis Therapy With Shark Variable Novel Antigen Receptor Domains Targeting Tumor Necrosis Factor Alpha or Inducible T-Cell Costimulatory Ligand

Purpose

We assess the efficacy of two next-generation biologic therapies in treating experimental autoimmune uveitis.

Methods

Variable binding domains from shark immunoglobulin novel antigen receptors (VNARs) were fused with a mouse IgG2a constant domain (Fc) to generate VNAR-Fc molecules with binding specificity to tumor necrosis factor alpha (TNFα) or inducible T-cell costimulatory ligand (ICOSL). Treatment with VNAR-Fc fusion proteins was compared to treatment with dexamethasone or vehicle in the Lewis rat model of experimental autoimmune uveitis (EAU). Inflammation control was determined by comparing OCT clinical and histologic scores, and aqueous humor protein concentration. The concentration of 27 inflammatory cytokines in the aqueous humor was measured using a multiplex enzyme-linked immunosorbent assay platform.

Results

Administration of S17-Fc significantly decreased clinical, histologic, and aqueous protein levels when compared to vehicle treatment. Inflammation scores and aqueous protein levels in A5-Fc–treated animals were decreased compared to vehicle treatment, but not significantly. The concentration of vascular endothelial growth factor (VEGF), regulated on activation, normal T cell expressed and secreted (RANTES), macrophage inflammatory protein 1 alpha (MIP-1α), interleukin (IL)-1β, LPS-induced CXC chemokine (LIX), monocyte chemoattractant protein-1 (MCP-1), and interferon (IFN)-γ were significantly decreased in the eyes of animals treated with dexamethasone. VNAR treatment demonstrated a trend towards decreased cytokine concentrations, but only VEGF and RANTES were significantly decreased by S17-Fc.

Conclusions

Treatment with the anti-TNFα VNAR S17-Fc ameliorates EAU as effectively as treatment with corticosteroids.

Translational Relevance

VNAR-Fc molecules are a next-generation therapeutic biologic that overcome the limitations of classical biologic monoclonal antibodies, such as complex structure, large size, and limited tissue penetration. This is a novel drug modality that could result in the development of new therapy options for patients with noninfectious uveitis.

TNF-Alpha Inhibition and Other Immunosuppressants in the Development of Uveal and Cutaneous Melanoma

OBJECTIVE

To investigate an association between tumor necrosis factors-alpha (TNFα) inhibitors or other immunosuppressants and the development of uveal and cutaneous melanoma.

PATIENTS AND METHODS

We performed a retrospective incidence and case-control analysis of patients in Olmsted County, MN, who were diagnosed with uveal or cutaneous melanoma from January 1, 2000, to December 31, 2014. Incidence was adjusted by age and gender to the 2010 US white population. Controls were matched by sex and age to cases at time of diagnosis of melanoma.

RESULTS

There were 1221 cases of melanoma (33 uveal, 1188 cutaneous). Combined incidence of uveal and cutaneous melanoma per 100,000 person-years varied by gender (male > female), age (older > younger), and time period: 2010 to 2014 (77.9, 95% confidence interval [CI], 71.1-84.7) ≈ 2005 to 2009 (78.0, 95% CI, 70.9-85.0) > 2000 to 2004 (42.5, 95% CI, 36.9-48.1, P<.001). TNFa inhibitor prescription was not associated with significantly increased risk of melanoma vs controls (1.06% vs 0.41%, P=.06). Immunosuppressive agents, high-dose corticosteroids, and topical immunosuppressants were associated with melanoma (odds ratio [OR] 1.42 CI, 1.03-1.95, 3.30 CI, 2.44-4.48, and 1.87 CI, 1.06-3.28, respectively). An increased number of patients with uveal melanoma received immune modulating agents vs controls, but this was not statistically significant (P=.36). Autoimmune disease itself was not correlated with melanoma (P=.73).

CONCLUSION

Exposure to immunosuppressive agents is associated with melanoma. TNFa inhibition and autoimmune disease alone do not significantly increase risk of melanoma. In patients receiving immunosuppressive treatments, physicians should consider monitoring with dilated ophthalmic and full-body skin examinations. Further studies are needed to assess the impact of TNFa inhibitors on development of melanoma, particularly in uveal melanoma.

Ocular complications of tumour necrosis factor alpha inhibitors

Tumour necrosis factor alpha inhibitors are a relatively recent development and are becoming increasingly common in the management of many chronic inflammatory conditions such as rheumatoid arthritis, inflammatory bowel disease, ankylosing spondylitis and juvenile idiopathic arthritis. However, their ocular side effect profile is incomplete and poorly recognised, with mostly anecdotal cases reported in the literature. In this report we review the literature regarding ocular side effects associated with tumour necrosis factor alpha blockade.

Anti-tumour necrosis factor biological therapies for the treatment of uveitic macular oedema (UMO) for non-infectious uveitis

BACKGROUND

Non-infectious uveitis describes a heterogenous group of ocular disorders characterised by intraocular inflammation in the absence of infection. Uveitis is a leading cause of visual loss, most commonly due to uveitic macular oedema (UMO). Treatment is aimed at reducing disease activity by suppression of the intraocular inflammatory response. In the case of macular oedema, the aim is to restore macular architecture as quickly as possible, in order to prevent irreversible photoreceptor damage in this area. Acute exacerbations are typically managed with corticosteroids, which may be administered topically, locally or systemically. Whilst these are often rapidly effective in achieving disease control, long-term use is associated with significant local and systemic side effects, and 'steroid sparing agents' are typically used to achieve prolonged control in severe or recalcitrant disease. Anti-tumour necrosis factor (TNF) drugs block a critical cytokine in the inflammatory signalling process, and have emerged as effective steroid-sparing immunomodulatory agents in a wide range of non-ocular conditions. There is mechanistic data to suggest that they may provide a more targeted approach to disease control in UMO than other agents, but to date, these agents have predominantly been used 'off label' as the majority are not licensed for ocular use. This review aims to summarise the available literature reporting the use of anti-TNF therapy in UMO, thus developing the evidence-base on which to make future treatment decisions and develop clinical guidelines in this area.

OBJECTIVES

To assess the efficacy of anti-TNF therapy in treatment of UMO.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2018, Issue 2), which contains the Cochrane Eyes and Vision Trials Register; Ovid MEDLINE; Ovid Embase; LILACS; Web of Science Conference Proceedings Citation Index- Science (CPCI-S); System for Information on Grey Literature in Europe (OpenGrey); the ISRCTN registry; ClinicalTrials.gov and the WHO ICTRP. The date of the search was 29 March 2018.

SELECTION CRITERIA

We planned to include all relevant randomised controlled trials assessing the use of anti-TNF agents in treatment of UMO. No limits were applied to participant age, gender or ethnicity. The primary comparisons of this review were: anti-TNF versus no treatment or placebo; anti-TNF versus another pharmacological agent; comparison of different anti-TNF drugs; comparison of different doses and routes of administration of the same anti-TNF drug. The primary outcome measure that we assessed for this review was best-corrected visual acuity (BCVA) in the treated eye. Secondary outcome measures were anatomical macular change, clinical estimation of vitreous haze and health-related quality of life.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles and abstracts retrieved through the database searches. We retrieved full-text reports of studies categorised as 'unsure' or 'include' after we had reviewed the abstracts. Two review authors independently reviewed each full-text report for eligibility. We resolved discrepancies through discussion.

MAIN RESULTS

We identified no completed or ongoing trial that was eligible for this Cochrane Review.

AUTHORS' CONCLUSIONS

Our review did not identify any evidence from randomised controlled trials for or against the role of anti-TNF agents in the management of UMO. Although there are a number of high-quality randomised controlled trials that demonstrate the efficacy of anti-TNF agents in preventing recurrence of inflammation in uveitis, the reported study outcomes do not include changes in UMO. As a result, there were insufficient data to conclude whether there was a significant treatment effect specifically for UMO. Future trials should be designed to include quantitative measures of UMO as primary study outcomes, for example by reporting the presence or absence of UMO, or by measuring central macular thickness for study participants. Furthermore, whilst UMO is an important complication of uveitis, we acknowledge that uveitis is associated with many significant structural and functional complications. It is not possible to determine treatment efficacy based on a single outcome measure. We recommend that future reviews of therapeutic interventions in uveitis should use composite measures of treatment response comprising a range of potential complications of disease.

Microglia in the Retina: Roles in Development, Maturity, and Disease

Microglia, the primary resident immune cell type, constitute a key population of glia in the retina. Recent evidence indicates that microglia play significant functional roles in the retina at different life stages. During development, retinal microglia regulate neuronal survival by exerting trophic influences and influencing programmed cell death. During adulthood, ramified microglia in the plexiform layers interact closely with synapses to maintain synaptic structure and function that underlie the retina's electrophysiological response to light. Under pathological conditions, retinal microglia participate in potentiating neurodegeneration in diseases such as glaucoma, retinitis pigmentosa, and age-related neurodegeneration by producing proinflammatory neurotoxic cytokines and removing living neurons via phagocytosis. Modulation of pathogenic microglial activation states and effector mechanisms has been linked to neuroprotection in animal models of retinal diseases. These findings have led to the design of early proof-of-concept clinical trials with microglial modulation as a therapeutic strategy.

Sustained Subconjunctival Delivery of Infliximab Protects the Cornea and Retina Following Alkali Burn to the Eye

Purpose

Tumor necrosis factor (TNF)-α is upregulated in eyes following corneal alkali injury and contributes to corneal and also retinal damage. Prompt TNF-α inhibition by systemic infliximab ameliorates retinal damage and improves corneal wound healing. However, systemic administration of TNF-α inhibitors carries risk of significant complications, whereas topical eye-drop delivery is hindered by poor ocular bioavailability and the need for patient adherence. This study investigates the efficacy of subconjunctival delivery of TNF-α antibodies using a polymer-based drug delivery system (DDS).

Methods

The drug delivery system was prepared using porous polydimethylsiloxane/polyvinyl alcohol composite fabrication and loaded with 85 μg of infliximab. Six Dutch-belted pigmented rabbits received ocular alkali burn with NaOH. Immediately after the burn, subconjunctival implantation of anti-TNF-α DDS was performed in three rabbits while another three received sham DDS (without antibody). Rabbits were followed with photography for 3 months.

Results

After 3 months, the device was found to be well tolerated by the host and the eyes exhibited less corneal damage as compared to eyes implanted with a sham DDS without drug. The low dose treatment suppressed CD45 and TNF-α expression in the burned cornea and inhibited retinal ganglion cell apoptosis and optic nerve degeneration, as compared to the sham DDS treated eyes. Immunolocalization revealed drug penetration in the conjunctiva, cornea, iris, and choroid, with residual infliximab in the DDS 3 months after implantation.

Conclusions

This reduced-risk biologic DDS improves corneal wound healing and provides retinal neuroprotection, and may be applicable not only to alkali burns but also to other inflammatory surgical procedures such as penetrating keratoplasty and keratoprosthesis implantation.

Intravitreal injection of anti-Interleukin (IL)-6 antibody attenuates experimental autoimmune uveitis in mice

PURPOSE

To evaluate the effect of an intravitreally applied anti-IL-6 antibody for the treatment of experimental autoimmune uveitis (EAU).

METHODS

EAU was induced in female B10.RIII mice by Inter-Photoreceptor-Binding-Protein (IRBP) in complete Freund's adjuvant, boosted by Pertussis toxin. Single blinded intravitreal injections of anti-IL-6 antibody were applied 5-7days as well as 8-10days (3day interval) after EAU induction into the randomized treatment eye and phosphate buffered saline (PBS) into the fellow control eye. Clinical and fluorescein angiography scoring (6 EAU grades) was done at each injection day and at enucleation day 14. Enucleated eyes were either scored histologically (6 EAU grades) or examined by ELISA for levels of IL-6, IL-17 and IL-6 soluble Receptor (sIL-6R).

RESULTS

Uveitis developed in all 12 mice. Clinical uveitis score was significantly reduced (p=0.035) in treated eyes (median 2.0, range 0-4.0, n=12) compared to the fellow control eyes (median 3.0, range 1.0-4.0, n=12). Angiography scores were reduced in 9/12 treated eyes and histological scores in 3/4 treated eyes compared to the fellow control eyes. Cytokine levels were determined in 8 mice, of which 4 responded to anti-IL-6 treatment and 4 did not respond. All mice responding to treatment had a significant reduction of IL-6 (p<0.01) and IL-17 (p=0.01) levels in treated eyes compared to the fellow control eyes. This difference was not seen in non-responding mice.

CONCLUSIONS

Intravitreal anti-IL-6 treatment significantly attenuates experimental autoimmune uveitis in mice. EAU activity correlates with ocular IL-6 and IL-17 levels.

TNFa knockdown in the retina promotes cone survival in a mouse model of autosomal dominant retinitis pigmentosa

Expression of T17M rhodopsin (T17M) in rods activates the Unfolded Protein Response (UPR) and leads to the development of autosomal dominant retinitis pigmentosa (adRP). The rod death occurs in adRP retinas prior to cone photoreceptor death, so the mechanism by which cone photoreceptors die remains unclear. Therefore, the goal of the study was to verify whether UPR in rods induces TNFa-mediated signaling to the cones and to determine whether the TNFa deficit could prevent adRP cone cell death. Primary rod photoreceptors and cone-derived 661W cells transfected with siRNA against TNFa were treated with tunicamycin to mimic activation of UPR in T17M retinas expressing normal and reduced TNFa levels. The 661W cells were then exposed to recombinant TNFa to evaluate cell viability. In vivo, the role of TNFa was assessed in T17M TNFa^+/- mice by electroretinography, optical coherence tomography, histology, immunohistochemistry, and a cytokine enzyme-linked immunosorbent assay. Rods overexpressed and secreted TNFa in response to UPR activation. The recombinant TNFa treatment lowered the number of viable cones, inducing cell death through elevation of pro-inflammatory cytokines and caspase-3/7 activity. The TNFa deficiency significantly protected adRP retinas. The photopic ERG amplitudes and the number of surviving cones dramatically increased in T17M TNFa^+/- mice. This neuroprotection was associated with a reduced level of pro-inflammatory cytokines. Our results indicate that rod photoreceptors, following UPR activation during adRP progression, secrete TNFa and signal a self-destructive program to the cones, resulting in their cell death. TNFa therefore holds promise as a therapeutic target for treatment of adRP.

Blockade of Tumor Necrosis Factor-Alpha: A Role for Adalimumab in Neovascular Age-Related Macular Degeneration Refractory to Anti-Angiogenesis Therapy?

AIMS

To report a case of wet age-related macular degeneration (wet-AMD) refractory to intravitreal anti-vascular endothelial growth factor (anti-VEGF) therapy in a patient who showed visual and anatomical improvement and stabilization after starting a subcutaneous treatment course with adalimumab, an anti-tumor necrosis factor-alpha (TNF-α) drug, for concomitant Crohn's disease.

METHODS

Observational case report of a female patient. Ophthalmological evaluation was performed by slit lamp and ophthalmoscopy (posterior pole and anterior segment). Best-corrected visual acuity (BCVA) was determined, and imaging was performed by fluorescein angiography, indocyanine green angiography, and optical coherence tomography (OCT). Intravitreal therapies used and treatment with anti-TNF-α were recorded.

RESULTS

A 64-year-old woman with wet-AMD was treated with fourteen intravitreal injections of ranibizumab (0.5 mg) for a period of 40 months with intervals of 1-6 months. She initially showed a good visual and anatomical response to periodic anti-VEGF treatment but during check visits, anatomical and functional responses deteriorated. At the 40-month follow-up, the patient had developed Crohn's disease, and her rheumatologist started treatment with adalimumab (40 mg subcutaneously every 2 weeks). During the 25 months of treatment with adalimumab, the patient did not require any additional intravitreal anti-VEGF treatments because her BCVA, clinical, and OCT findings improved and remained stable.

CONCLUSIONS

We described a case of a patient with wet-AMD refractory to anti-VEGF therapy, which clinically benefited from subcutaneous adalimumab therapy. Treatment with subcutaneous anti-TNF-α in combination with anti-VEGF therapy avoids the high cost and risks related to multiple intravitreal anti-VEGF injections with good functional and anatomic outcomes.

Safety of monoclonal antibodies and related therapeutic proteins for the treatment of neovascular macular degeneration: addressing outstanding issues

INTRODUCTION

The vascular endothelial growth factor (VEGF) inhibitors most widely used to treat neovascular age-dependent macular degeneration (nAMD) are different proteins with structural features potentially relevant to adverse effects (AEs). Two of these are also established in cancer therapy (with higher dosages and AEs). The importance of ocular AE and extraocular activities is still a subject of controversy and ongoing research.

AREAS COVERED

Potential risks of intraocular VEGF inhibition based on prospective studies, in vitro investigations, pharmacokinetics, and hints from anti-cancer treatment.

EXPERT OPINION

nAMD is a frequently observed chronic clinical condition severely affecting the visual function of elderly persons. Intravitreal injection of VEGF-inactivating proteins is highly effective to prevent loss of vision. Anti-VEGF therapy is well tolerated, and low rates of ocular and systemic AEs in smaller trials suggest a very high benefit/risk ratio. The proteins established in nAMD therapy show similar efficacies. In the controversy over the off-label use of bevacizumab purely on grounds of much lower cost, the small, but potentially relevant differences between the available drugs are easily either dramatized (by pharmaceutical companies) or trivialized (by health insurances) and even political interference is involved. Facing the lack of a convincing body of evidence regarding safety, further long-term study results seem necessary.