Pharmacogenetics of drugs used in the treatment of ocular inflammatory diseases

Perspectives of Therapeutic Drug Monitoring of Biological Agents in Non-Infectious Uveitis Treatment: A Review

Biological drugs, especially those targeting anti-tumour necrosis factor α (TNFα) molecule, have revolutionized the treatment of patients with non-infectious uveitis (NIU), a sight-threatening condition characterized by ocular inflammation that can lead to severe vision threatening and blindness. Adalimumab (ADA) and infliximab (IFX), the most widely used anti-TNFα drugs, have led to greater clinical benefits, but a significant fraction of patients with NIU do not respond to these drugs. The therapeutic outcome is closely related to systemic drug levels, which are influenced by several factors such as immunogenicity, concomitant treatment with immunomodulators, and genetic factors. Therapeutic drug monitoring (TDM) of drug and anti-drug antibody (ADAbs) levels is emerging as a resource to optimise biologic therapy by personalising treatment to bring and maintain drug concentration within the therapeutic range, especially in those patients where a clinical response is less than expected. Furthermore, some studies have described different genetic polymorphisms that may act as predictors of response to treatment with anti-TNFα agents in immune-mediated diseases and could be useful in personalising biologic treatment selection. This review is a compilation of the published evidence in NIU and in other immune-mediated diseases that support the usefulness of TDM and pharmacogenetics as a tool to guide clinicians’ treatment decisions leading to better clinical outcomes. In addition, findings from preclinical and clinical studies, assessing the safety and efficacy of intravitreal administration of anti-TNFα agents in NIU are discussed.

Blocking the inflammasome: A novel approach to treat uveitis

Uveitis is a complex ocular inflammatory disease often accompanied by bacterial or viral infections (infectious uveitis) or underlying autoimmune diseases (non-infectious uveitis). Treatment of the underlying infection along with corticosteroid-mediated suppression of acute inflammation usually resolves infectious uveitis. However, to develop more effective therapies for non-infectious uveitis and to better address acute inflammation in infectious disease, an improved understanding of the underlying inflammatory pathways is needed. In this review, we discuss the disease aetiology, preclinical in vitro and in vivo uveitis models, the role of inflammatory pathways, as well as current and future therapies. In particular, we highlight the involvement of the inflammasome in the development of non-infectious uveitis and how it could be a future target for effective treatment of the disease.

New therapies in development for the management of non-infectious uveitis: A review

Uveitis is a spectrum of inflammatory disorders characterized by ocular inflammation and is one of the leading causes of preventable visual loss. The main aim of the treatment of uveitis is to control the inflammation, prevent recurrences of the disease and preserve vision while minimizing the adverse effects associated with the therapeutic agents. Initial management of uveitis relies heavily on the use of corticosteroids. However, monotherapy with high-dose corticosteroids is associated with side effects and cannot be maintained long term. Therefore, steroid-sparing agents are needed to decrease the burden of steroid therapy. Currently, the therapeutic approach for non-infectious uveitis (NIU) consists of a step-ladder strategy with the first-line option being corticosteroids in various formulations followed by the use of first-, second- and third-line agents in cases with suboptimal steroid response. Unfortunately, the agents currently at our disposal have limitations such as having a narrow therapeutic window along with their own individual potential side-effect profiles. Therefore, research has been targeted to identify newer drugs as well as new uses for older drugs that target specific pathways in the inflammatory response. Such efforts are made in order to provide targeted and safer therapy with reduced side effects and greater efficacy. Several specially designed molecular antibodies are currently in various phases of investigations that can potentially halt the inflammation in patients with NIU. In the review, we have provided a comprehensive overview of the current and upcoming therapeutic options for patients with NIU.

Augmenting Endogenous Levels of Retinal Annexin A1 Suppresses Uveitis in Mice

PURPOSE

The purpose of this study was to examine the expression of the anti-inflammatory protein Annexin A1 (AnxA1) in mice and human retinae during uveitis and to determine whether local administration of human recombinant AnxA1 (hrAnxA1) can suppress uveitis in mice.

METHODS

Retinal sections from mice (healthy normal and uveitis) and postmortem human (no history of eye disease (n = 5) and uveitis (n = 7)) were stained for AnxA1 expression and imaged by immunofluorescence microscopy. AnxA1 cellular expression was determined by colabeling with CD45, glial fibrillary acidic protein (GFAP), and Iba-1 cells, with additional staining of AnxA1 receptors formyl peptide receptor 1 (FPR1) and FPRL1/FPR2. Mice with acute endotoxin-induced uveitis and chronic experimental autoimmune uveitis were treated locally by intravitreal injection with hrAnxA1, and disease was assessed by clinical scoring and quantification of leukocyte infiltrate via flow cytometry.

RESULTS

Constitutive expression of AnxA1 was observed in both healthy mouse and human retinae, and its expression increased during uveitis compared to healthy controls. AnxA1 colocalizes predominantly with CD45⁺ cells, GFAP⁺ macroglia, and to a lesser extent, Iba-1⁺ myeloid cells. We also demonstrate that local treatment with hrAnxA1 attenuates the severity of uveitis in mice.

CONCLUSIONS

These data indicate that locally expressed AnxA1 is elevated in the retina during intraocular inflammation. We demonstrate that local administration of hrAnxA1 to augment levels results in suppression of uveitis in mice.

TRANSLATIONAL RELEVANCE

Our data suggest that elevated expression of retinal AnxA1 in human uveitis may be immunoregulatory and that local supplementation with hrAnxA1 may provide a potential novel treatment for inflammatory eye diseases such as noninfectious uveitis.

A review and update on orphan drugs for the treatment of noninfectious uveitis

Introduction

Uveitis, a leading cause of preventable blindness around the world, is a critically underserved disease in regard to the medications approved for use. Multiple immunomodulatory therapy (IMT) drugs are appropriate for uveitis therapy but are still off-label. These IMT agents, including antimetabolites, calcineurin inhibitors, alkylating agents, and biologic agents, have been designated as “orphan drugs” and are widely used for systemic autoimmune diseases or organ transplantation.

Area covered

The purpose of this paper is to comprehensively review and summarize the approved orphan drugs and biologics that are being used to treat systemic diseases and to discuss drugs that have not yet received approval as an “orphan drug for treating uveitis” by the US Food and Drug Administration (FDA).

Our perspective

IMT, as a steroid-sparing agent for uveitis patients, has shown promising clinical results. Refractory and recurrent uveitis requires combination IMT agents. IMT is continued for a period of 2 years while the patient is in remission before considering tapering medication. Our current goals include developing further assessments regarding the efficacy, optimal dose, and safety in efforts to achieve FDA approval for “on-label” use of current IMT agents and biologics more quickly and to facilitate insurance coverage and expand access to the products for this orphan disease.

Transglutaminase binding fusion protein linked to SLPI reduced corneal inflammation and neovascularization

BACKGROUND

To study the effect of topical administration of a fusion protein (PF-MC) made up of N-terminal portion of the protease inhibitor Trappin-2 (which is a substrate of transglutaminasa-2) and SLPI (protein with anti-inflammatory, anti-bacterial and anti-viral ability), in an animal model of corneal inflammation and angiogenesis.

METHODS

An alkali injury was produced with a filter paper of 3 mm with 1 N NaOH during 40 seconds on the right cornea of 36 male Sprague Dawley rats, under general anesthesia. Animals were divided into three groups according to treatment. Group 1 was treated with 10 ul of PF-MC (200 ug/ml; n = 12), Group 2, with 10 ul of SLPI (200 ug/ml; n = 12) and Group 3 was treated with buffer (10 ul; n = 12) topically administered four times a day for up to 7 days. Half of the animals were sacrificed at day 3 before making a re-epithelialization time analysis with fluorescein staining at 18 and 24 hours. In the remaining animals corneal opacity was studied and digital photographs were taken at day 7 before doing euthanasia. Eyes were processed for histology and immunofluorescence.

RESULTS

Corneal ulcerated area was significantly lower in PF-MC treated animals compared to SLPI and buffer-treated animals at 18 hours and 24 hours postinjury. A clear cornea and fundus red reflex was only found among PF-MC treated animals. Histological analysis revealed a stratified corneal epithelium with at least three layers in all PF-MC animals at day 7. In this group there was a reduced number of PMNs in the corneal stroma at 3 and 7 days of follow-up. Besides, corneal neovascularization was much more extended in SLPI and Buffer animals than in animals treated with PF-MC.

CONCLUSIONS

The binding of SLPI with Cementoin to transglutaminase seems to be an effective strategy to treat corneal inflammation and angiogenesis.