The efficacy of sirolimus in the treatment of patients with refractory uveitis

Factors Associated With Intraocular Inflammation in Neovascular Age-Related Macular Degeneration Patients Treated With Brolucizumab

Purpose

To identify factors associated with intraocular inflammation (IOI) in patients with neovascular age-related macular degeneration (nAMD) treated with brolucizumab.

Methods

In this prospective observational study, we collected aqueous humor samples from 96 eyes of 96 patients receiving treatment with brolucizumab; IOI subsequently developed in 19 eyes of 19 patients. To identify cytokines upregulated in eyes with subsequent development of IOI, we compared the aqueous humor cytokine levels between the IOI and non-IOI groups. We also collected plasma from 20 patients who developed IOI and 20 age- and sex-matched controls to identify differences in plasma biomarkers and the subfraction of CD4+ cells. Using stepwise variable selection and multivariate binary regression analysis, we developed an algorithm that accurately assessed the likelihood of IOI occurrence.

Results

The IOI group showed elevated aqueous humor levels of P-selectin (584 vs. 324 pg/mL, P = 0.013), TNF-α (0.89 vs. 0.60 pg/mL, P = 0.018), and IL-1α (2.0 vs. 1.4 pg/mL, P = 0.035) compared with the non-IOI group. Serum MMP-9 concentrations were higher in the IOI group than the non-IOI group (18,310 vs. 13,450 pg/mL, P = 0.029). Furthermore, the percentage of Th2 cells was significantly decreased in the IOI compared with the non-IOI group (3.1% vs. 4.2%, P = 0.013). The receiver operating characteristic curves for the optimal models showed an area under the curve ranging from 0.71 to 0.89, indicating good performance.

Conclusions

The combination of elevated concentrations of multiple aqueous humor cytokines and of serum MMP-9 and a lower number of plasma Th2 cells is associated with brolucizumab-related IOI in patients with nAMD.

T cells in ocular autoimmune uveitis: Pathways and therapeutic approaches

Autoimmune uveitis is a non-infectious intraocular condition that affects the uveal tract of the eye and threatens vision if not treated properly. Increasing evidence suggests that activated CD4⁺ T cells are associated with progressive and permanent destruction of photoreceptors in ocular autoimmune diseases. As such, the purpose of this review is to offer an overview of the role of CD4⁺ T cells in autoimmune uveitis as well as a justification for the current development and assessment of innovative autoimmune uveitis medications targeting CD4⁺ T cells. With an emphasis on T helper (Th)17, Th1, and Th2 cells, follicular helper CD4⁺ T cells, and regulatory T cells, this review presents a summary of recent research related to the pathways and signaling that encourage CD4⁺ T cells to develop into specialized effector cells. We also describe immunotherapeutic approaches based on CD4⁺ T cell subsets and their potential as therapeutic agents for autoimmune disorders.

Intermediate Uveitis: A Review

PURPOSE

This review aims to provide an update on the clinical presentation, etiologies, complications, and treatment options in intermediate uveitis (IU).

METHODS

Narrative literature review.

RESULTS

IU affects all age groups with no clear gender predominance and has varied etiologies including systemic illnesses and infectious diseases, or pars planitis. In some instances, IU may be the sole presentation of an underlying associated condition or disease. Management of IU and its complications include administration of corticosteroids, antimetabolites, T-cell inhibitors, and/or biologics, along with surgical interventions, with varying degrees of effectiveness across literature. In particular, increasing evidence of the safety and efficacy of immunomodulatory agents and biologics has seen greater adoption of these therapies in clinical practice.

CONCLUSIONS

IU is an anatomical description of uveitis, involving intraocular inflammation of the vitreous, peripheral retinal vasculature, and pars plana. Various treatment options for intermediate uveitis are currently used in practice.

The Topical Ocular Delivery of Rapamycin to Posterior Eye Tissues and the Suppression of Retinal Inflammatory Disease

Treatment of posterior eye diseases with intravitreal injections of drugs, while effective, is invasive and associated with side effects such as retinal detachment and endophthalmitis. In this work, we have formulated a model compound, rapamycin (RAP), in nanoparticle-based eye drops and evaluated the delivery of RAP to the posterior eye tissues in a healthy rabbit. We have also studied the formulation in experimental autoimmune uveitis (EAU) mouse model with retinal inflammation. Aqueous RAP eye drops were prepared using N-palmitoyl-N-monomethyl-N,N-dimethyl-N,N,N-trimethyl-6-O-glycolchitosan (Molecular Envelope Technology - MET) containing 0.23 ± 0.001% w/v RAP with viscosity, osmolarity, and pH within the ocular comfort range, and the formulation (MET-RAP) was stable in terms of drug content at both refrigeration and room temperature for one month. The MET-RAP eye drops delivered RAP to the choroid-retina with a Cmax of 145 ± 49 ng/g (tmax = 1 hour). The topical application of the MET-RAP eye drops to the EAU mouse model resulted in significant disease suppression compared to controls, with activity similar to dexamethasone eye drops. The MET-RAP eye drops also resulted in a reduction of RORγt and an increase in both Foxp3 expression and IL-10 secretion, indicating a mechanism involving the inhibition of Th17 cells and the up-regulation of T-reg cells. The MET-RAP formulation delivers RAP to the posterior eye segments, and the formulation is active in EAU.

A Review of Ocular Drug Delivery Platforms and Drugs for Infectious and Noninfectious Uveitis: The Past, Present, and Future

Uveitis refers to a broad group of inflammatory disorders of the eye that often require medical and surgical management to improve or stabilize vision and prevent vision-threatening pathological changes to the eye. Drug delivery to the eye to combat inflammation and subsequent complications from uveitic conditions is complex as there are multiple barriers to absorption limiting availability of the needed drug in the affected tissues. As such, there has been substantial interest in developing new drugs and drug delivery platforms to help reduce intraocular inflammation and its complications. In this review, we discuss the challenges of drug delivery, novel technologies recently approved for uveitis patient care and promising drug delivery platforms for uveitis and sequelae of ocular inflammation.

Ultra-thin, high strength, antibiotic-eluting sutures for prevention of ophthalmic infection

Sutures are applied almost universally at the site of trauma or surgery, making them an ideal platform to modulate the local, postoperative biological response, and improve surgical outcomes. To date, the only globally marketed drug-eluting sutures are coated with triclosan for antibacterial application in general surgery. Loading drug directly into the suture rather than coating the surface offers the potential to provide drug delivery functionality to microsurgical sutures and achieve sustained drug delivery without increasing suture thickness. However, conventional methods for drug incorporation directly into the suture adversely affect breaking strength. Thus, there are no market offerings for drug-eluting sutures, drug-coated, or otherwise, in ophthalmology, where very thin sutures are required. Sutures themselves help facilitate bacterial infection, and antibiotic eye drops are commonly prescribed to prevent infection after ocular surgeries. An antibiotic-eluting suture may prevent bacterial colonization of sutures and preclude patient compliance issues with eye drops. We report twisting of hundreds of individual drug-loaded, electrospun nanofibers into a single, ultra-thin, multifilament suture capable of meeting both size and strength requirements for microsurgical ocular procedures. Nanofiber-based polycaprolactone sutures demonstrated no loss in strength with loading of 8% levofloxacin, unlike monofilament sutures which lost more than 50% strength. Moreover, nanofiber-based sutures retained strength with loading of a broad range of drugs, provided antibiotic delivery for 30 days in rat eyes, and prevented ocular infection in a rat model of bacterial keratitis.

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.

Efficacy and Safety of Intravitreal Sirolimus for Noninfectious Uveitis of the Posterior Segment: Results from the Sirolimus Study Assessing Double-Masked Uveitis Treatment (SAKURA) Program

PURPOSE

To evaluate the efficacy and safety of intravitreal sirolimus in the management of noninfectious uveitis of the posterior segment (NIU-PS).

DESIGN

Combined analysis of 2 phase 3, randomized, double-masked, multinational, 6-month studies.

PARTICIPANTS

Adults with active NIU-PS (intermediate uveitis, posterior uveitis, or panuveitis; defined as vitreous haze [VH] ≥1.5+ on modified Standardization of Uveitis Nomenclature scale).

METHODS

Patients were randomized 1:1:1 to receive intravitreal sirolimus 44 μg (n = 208), 440 μg (n = 208), or 880 μg (n = 177) on days 1, 60, and 120. Patients discontinued medications for NIU-PS except for systemic corticosteroids, which were tapered according to protocol. Enrollment in the 880-μg group was terminated after interim results found no significant difference in efficacy compared with the 440-μg dose.

MAIN OUTCOME MEASURES

The primary efficacy end point was the percentage of patients with VH of 0 at month 5 in the study eye without the use of rescue therapy. Secondary efficacy end points included VH of 0 or 0.5+, corticosteroid-tapering success, and changes in best-corrected visual acuity (BCVA). Safety measures included ocular and nonocular adverse events.

RESULTS

A total of 592 patients were randomized. Significantly higher proportions of patients treated with 440 μg compared with 44 μg intravitreal sirolimus achieved VH of 0 (21.2% vs. 13.5%; P = 0.038) and VH of 0 or 0.5+ (50.0% vs. 40.4%; P = 0.049) at month 5. Best-corrected visual acuity was stable (absolute change <5 ETDRS letters) or improved >5 letters in 80.1% and 80.2% of patients in the 440-μg and 44-μg groups, respectively. At month 5, corticosteroids were tapered successfully in 69.6% and 68.8% of patients in the 440-μg and 44-μg groups, and among these patients, VH of 0 or 0.5+ was achieved by 43.5% and 28.1% in the 440-μg and 44-μg groups. Both doses were generally well tolerated. Mean changes from baseline intraocular pressure (IOP) in the study eye at each analysis visit were minimal in all treatment groups.

CONCLUSIONS

Intravitreal sirolimus 440 μg improved ocular inflammation, as measured by VH, compared with the 44-μg dose, with minimal impact on IOP, while preserving BCVA.

Safety of systemic therapy for noninfectious uveitis

Introduction: The treatment strategies for noninfectious uveitis (NIU) aim to achieve disease remission, prevention of recurrences, and preserving vision, while minimizing the side effects associated with the therapies used.Areas covered: The index review aims to provide a detailed overview of the adverse events and safety parameters associated with the systemic therapies for the management of the NIU.Expert opinion: Despite being the cornerstone of management of acute cases of NIU, long-term corticosteroid use is associated with multi-system side effects, requiring the use of steroid-sparing agents. Adalimumab was recently approved by the FDA for the management of NIU based on the results of VISUAL studies. Similarly, newer drugs targeting various aspects of the inflammatory cascade are being developed. However, until we completely understand the molecular pathways of the inflammatory diseases, the therapeutic profile of these newer agents needs to be broad enough to suppress inflammatory cascade and narrow enough to spare normal cellular processes. Another strategy that has shown some potential in decreasing the systemic side effects is to provide local drug delivery. Therefore, the future of management of NIU is very bright with many novel therapeutic agents and strategies of drug delivery on the horizon.

In vivo and in vitro toxicity evaluation of liposome-encapsulated sirolimus

Background

To evaluate the in vivo and in vitro toxicity of a new formulation of liposome-encapsulated sirolimus (LES).

Methods

In vitro experiments were done using ARPE-19 and HRP cells. An MTT assay was used to determine cell metabolic activity and a TUNEL assay for detecting DNA fragmentation. In vivo experiments were conducted on New Zealand albino rabbits that received intravitreal injections of empty liposomes (EL) or different concentrations of LES. Histopathological and immunohistochemical analyses were performed on the rabbit’s eyes following injection.

Results

Eighteen eyes of nine rabbits were used. MTT assay cell viability was 95.04% in group 1 (12.5 µL/mL LES). 92.95% in group 2 (25 µL/mL LES), 91.59% in group 3 (50 µL/mL LES), 98.09% in group 4 (12.5 µL/mL EL), 95.20% on group 5 (50 µL/mL EL), 98.53% in group 6 (50 µL/mL EL), and 2.84% on group 8 (50 µL/mL DMSO). There was no statistically significant difference among groups 1 to 7 in cell viability (p = 1.0), but the comparison of all groups with group 8 was significant (p < 0.0001). The TUNEL assay comparing two groups was not statistically significant from groups 1 to 7 (p = 1.0). The difference between groups 1 to 7 and group 8 (p < 0.0001) was significant. Histopathological changes were not found in any group. No activation of Müller cells was detected.

Conclusion

A novel formulation of LES delivered intravitreally did not cause in vitro toxicity, as evaluated by MTT and TUNEL assays, nor in vivo toxicity as evaluated by histopathology and immunohistochemistry in rabbit eyes.

Emerging drugs for the treatment of noninfectious uveitis

Introduction: Uveitis is a leading cause of visual impairment and a significant burden of blindness. Although corticosteroids and conventional immunosuppressive agents have been successfully used, these are non-specific, and their long-term use may induce significant adverse effects. Areas covered: This article discusses existing local and systemic applied treatments for ocular inflammation including corticosteroids, non-biologic, and biologic disease-modifying anti-rheumatic drugs (DMARD). Potential drugs being studied in clinical trials are introduced for both local and systemic use. Expert opinion: Treatment options for uveitis continue to expand. Still, more efforts and research are needed to better understand the mechanisms potentially leading to clinical trials.

Outcomes of treatment with sirolimus for non-infectious uveitis: a meta-analysis and systematic review

Background

Uveitis is a group of intraocular inflammatory diseases whose primary treatment involves immunosuppression. Although corticosteroids (CSs) remain the mainstay therapy, sirolimus is among the recently studied immunomodulatory drugs for treating noninfectious uveitis (NIU).

Objective

The aim of this review was to assess and summarize the updated evidence on the outcomes of treatment with sirolimus for NIU.

Materials and methods

Two reviewers conducted a systematic search on November 5, 2018, of electronic databases (EMBASE, MEDLINE, and The Cochrane Library) and clinical trial registers having no restrictions on language or publication date. The primary outcome was uveitis activity as measured by vitreous haze (VH), while the secondary outcomes included central macular thickness (CMT), best-corrected visual acuity (BCVA), CS-sparing effect, IOP elevation, and other adverse events. A meta-analysis was conducted on selected studies with appropriate clinical and methodological homogeneity.

Results

Seven studies were included and reviewed. Four randomized clinical trials were eligible for meta-analysis: SAVE 2013, One-year outcomes of the SAVE study, SAVE 2 2016, SAKURA 2016. The pooled proportions of inflammation control (VH improvement) were 38% (95% CI 16.19%-62.66%) during a 6-month follow-up and 49.97% (95% CI 16.19%-83.03%) during a 6- to 12-month follow-up with the latter showing a significantly higher response rate (p=0.0472). BCVA improvement was 62.2% (95% CI 33.17%-87.11%) during a 6-month follow-up and 56.86% (95% CI 20.91%-89.05%) during a 6- to 12-month follow-up with no significant difference between the two (p=0.3705). Increased IOP remained at 7.11% (95% CI 3.46%-12.68%) for both a 6-month follow-up and up to a 12-month follow-up duration. The CS-sparing effect of sirolimus was also well demonstrated. A reduction in CMT was observed, and only minor drug-related adverse events were reported in all the studies reviewed.

Conclusion

This review provided evidence that sirolimus is a promising treatment option for controlling inflammatory activity, improving visual acuity, and sparing CS use with minor adverse events for NIU.

Update in treatment of uveitic macular edema

Macular edema (ME) represents the most common cause for visual loss among uveitis patients. The management of uveitic macular edema (UME) may be challenging, due to its often recalcitrant nature. Corticosteroids remain the mainstay of treatment, through their capability of effectively controlling inflammation and the associated ME. Topical steroids may be effective in milder cases of UME, particularly in edema associated with anterior uveitis. Posterior sub-Tenon and orbital floor steroids, as well as intravitreal steroids often induce rapid regression of UME, although this may be followed by recurrence of the pathology. Intra-vitreal corticosteroid implants provide sustained release of steroids facilitating regression of ME with less frequent injections. Topical nonsteroidal anti-inflammatory drugs may provide a safe alternative or adjuvant therapy to topical steroids in mild UME, predominantly in cases with underlying anterior uveitis. Immunomodulators including methotrexate, mycophenolate mofetil, tacrolimus, azathioprine, and cyclosporine, as well as biologic agents, notably the anti-tumor necrosis factor-α monoclonal antibodies adalimumab and infliximab, may accomplish the control of inflammation and associated ME in refractory cases, or enable the tapering of steroids. Newer biotherapies have demonstrated promising outcomes and may be considered in persisting cases of UME.

Toxicity and in vivo release profile of sirolimus from implants into the vitreous of rabbits' eyes

PURPOSE

To assess the in vivo release profile and the retinal toxicity of a poly (lactic-co-glycolic acid) (PLGA) sustained-release sirolimus (SRL) intravitreal implant in normal rabbit eyes.

METHODS

PLGA intravitreal implants containing or not SRL were prepared, and the viability of ARPE-19 and hES-RPE human retinal cell lines was examined after 24 and 72 h of exposure to implants. New Zealand rabbits were randomly divided into two groups that received intravitreal implants containing or not SRL. At each time point (1-8 weeks), four animals from the SRL group were euthanized, the vitreous was collected, and drug concentration was calculated. Clinical evaluation of the eyes was performed weekly for 8 weeks after administration. Electroretinography (ERG) was recorded in other eight animals, four for each group, at baseline and at 24 h, 1, 4, 6, and 8 weeks after the injection. ERG was carried out using scotopic and photopic protocols. The safety of the implants was assessed using statistical analysis of the ERG parameters (a and b waves, a and b implicit time, B/A ratio, oscillatory potential, and Naka-Rushton analysis) comparing the functional integrity of the retina between the PLGA and SRL-PLGA groups. After the last electrophysiological assessment, the rabbits were euthanized and retinal histopathology was realized.

RESULTS

After 24 and 72 h of incubation with PLGA or SRL-PLGA implants, ARPE-19 and hES-RPE cells showed viability over 70%. The maximum concentration of SRL (199.8 ng/mL) released from the device occurred within 4 weeks. No toxic effects of the implants or increase in the intraocular pressure was observed through clinical evaluation of the eye. ERG responses showed no significant difference between the eyes that received PLGA or SRL-PLGA implants at baseline and throughout the 8 weeks of follow-up. No remarkable difference in retinal histopathology was detected in rabbit eyes treated with PLGA or SRL-PLGA implants.

CONCLUSIONS

Intravitreal PLGA or SRL-PLGA implants caused no significant reduction in cell viability and showed no evident toxic effect on the function or structure of the retina of the animals. SRL was released from PLGA implant after application in the vitreous of rabbits during 8 weeks.

Intravitreal Sirolimus for the Treatment of Noninfectious Uveitis: Evolution through Preclinical and Clinical Studies

In recent decades, the treatment paradigm for noninfectious intermediate uveitis, posterior uveitis, and panuveitis, a group of intraocular inflammatory diseases, has included systemic and local (periocular or intraocular) corticosteroids, biologics, and other steroid-sparing immunomodulatory therapy agents. Recently, an intravitreal formulation of sirolimus, an immunosuppressant that inhibits the mammalian target of rapamycin, a key regulator of cell growth in the immune system, was developed. On the basis of this mechanism and the local method of delivery, it was hypothesized that intravitreal sirolimus can improve ocular inflammation in patients with noninfectious intermediate uveitis, posterior uveitis, and panuveitis, with minimal systemic exposure and systemic adverse events (AEs). This review summarizes the pharmacokinetics, efficacy, and safety results of intravitreal sirolimus from 3 preclinical studies and 4 phase 1-3 clinical studies. Preclinical studies in rabbits showed that 22 to 220 μg intravitreal sirolimus results in sustained release of sirolimus in the vitreous for 2 months or more, with systemic concentrations below the threshold for systemic immunosuppression (approximately 8 ng/ml). Subsequently, 2 phase 1 studies (n = 50 and n = 30) established that intravitreal sirolimus improves ocular inflammation in humans. Further investigation in phase 2 and 3 studies (n = 24 and n = 347, respectively) suggested that 440 μg has the best benefit-to-risk profile. In the phase 3 study, the proportion of patients who showed complete resolution of ocular inflammation at month 5 was significantly higher in the 440-μg group than in the 44-μg group (22.8% vs. 10.3%; P = 0.025, Fisher exact test). In addition, 47 of 69 patients (68.1%) who were treated with systemic corticosteroids at baseline discontinued corticosteroid use at month 5. No sirolimus-related systemic AEs were reported in phase 1-3 studies. Collectively, these preclinical and clinical study data of intravitreal sirolimus support the therapeutic rationale of treating noninfectious uveitis with a local mammalian target of rapamycin inhibitor and suggest that 440 μg intravitreal sirolimus has the potential to be an effective and well-tolerated anti-inflammatory and corticosteroid-sparing treatment for noninfectious intermediate uveitis, posterior uveitis, and panuveitis.

Novel everolimus-loaded nanocarriers for topical treatment of murine experimental autoimmune uveoretinitis (EAU)

In the present study, therapeutic effect of topically applied everolimus (EV)-loaded methoxy-poly(ethylene-glycol)-hexyl substituted poly (lactic acid) (mPEGhexPLA) nanocarriers on experimental autoimmune uveoretinitis (EAU) were investigated. EAU was induced in B10.RIII mice via immunization with human interphotoreceptor retinoid-binding protein peptide 161-180 (hIRBPp161-180) in complete Freund's adjuvant. Everolimus-loaded mPEGhexPLA (EV/mPEGhexPLA) nanocarriers were prepared by using a solvent evaporation method. On days 12-21 postimmunization (p.i.), the right eyes were treated five times daily either with 10 μl of 0.5% everolimus formulation or PBS (control). The EAU score of the eyes was determined histologically. On day 21 p.i., the peripheral immune responses were measured in serum, cervical lymph nodes (LN), and spleens via hIRBPp161-180-specific serum antibodies, cytokine secretion (ELISA), lymphocyte proliferation, and FoxP3+ regulatory T cells (Treg; flow cytometry). Compared to the PBS-treated mice, unilateral topical everolimus treatment significantly reduced EAU severity in both eyes (p < .05). The treatment reduced the antigen (Ag)-specific hIRBPp161-180-induced proliferation (p < .05), IL-2, IL-17, and IFN-γ secretion from cells isolated from the left and right cervical LN (p < .05). Under everolimus treatment, IL-10 secretion and CD4⁺CD25⁺FoxP3⁺ Treg frequency from cervical LN were enhanced. The proliferative response and cytokine secretion as well as the frequency of splenic Treg were almost unchanged. Topical administration of an everolimus formulation improved EAU in both eyes. The effect might also be related to systemic immunosuppressive effects, as several systemic cellular immune responses were influenced.

Small molecules as therapy for uveitis: a selected perspective of new and developing agents

INTRODUCTION

Intraocular inflammation (uveitis) remains a significant burden of legal blindness. Because of its immune mediated and chronic recurrent nature, common therapy includes corticosteroids, disease-modifying anti-rheumatic drugs and more recently biologics as immune modulatory agents. The purpose of this article is to identify the role of new treatment approaches focusing on small molecules as therapeutic option in uveitis. Areas covered: A MEDLINE database search was conducted through February 2017 using the terms 'uveitis' and 'small molecule'. To provide ongoing and future perspectives in treatment options, also clinical trials as registered at ClinicalTrials.gov were included. Both, results from experimental as well as clinical research in this field were included. Since this field is rapidly evolving, a selection of promising agents had to be made. Expert opinion: Small molecules may interfere at different steps of the inflammatory cascade and appear as an interesting option in the treatment algorithm of uveitis. Because of their highly targeted molecular effects and their favorable bioavailability with the potential of topical application small molecules hold great promise. Nevertheless, a careful evaluation of these agents has to be made, since current experience is almost exclusively based on experimental uveitis models and few registered trials.

Intravitreal Sirolimus for Noninfectious Uveitis: A Phase III Sirolimus Study Assessing Double-masKed Uveitis TReAtment (SAKURA)

PURPOSE

To evaluate the efficacy and safety of intravitreal sirolimus in the treatment of noninfectious uveitis (NIU) of the posterior segment (i.e., posterior, intermediate, or panuveitis).

DESIGN

Phase III, randomized, double-masked, active-controlled, 6-month study with intravitreal sirolimus.

PARTICIPANTS

Adults with active NIU of the posterior segment (intermediate, posterior, or panuveitis), defined as a vitreous haze (VH) score >1+. Subjects discontinued NIU medications before baseline, except for systemic corticosteroids, which were allowed only for those already receiving them at baseline and were rapidly tapered after baseline per protocol.

METHODS

Intravitreal sirolimus assigned 1:1:1 at doses of 44 (active control), 440, or 880 μg, administered on Days 1, 60, and 120.

MAIN OUTCOME MEASURES

The primary efficacy outcome was the percentage of subjects with VH 0 response at Month 5 (study eye) without use of rescue therapy. Secondary outcomes at Month 5 were VH 0 or 0.5+ response rate, corticosteroid tapering success rate (i.e., tapering to a prednisone-equivalent dosage of ≤5 mg/day), and changes in best-corrected visual acuity (BCVA). Adverse events during the double-masked treatment period are presented.

RESULTS

A total of 347 subjects were randomized. Higher proportions of subjects in the intravitreal sirolimus 440 μg (22.8%; P = 0.025) and 880 μg (16.4%; P = 0.182) groups met the primary end point than in the 44 μg group (10.3%). Likewise, higher proportions of subjects in the 440 μg (52.6%; P = 0.008) and 880 μg (43.1%; P = 0.228) groups achieved a VH score of 0 or 0.5+ than in the 44 μg group (35.0%). Mean BCVA was maintained throughout the study in each dose group, and the majority of subjects receiving corticosteroids at baseline successfully tapered off corticosteroids (44 μg [63.6%], 440 μg [76.9%], and 880 μg [66.7%]). Adverse events in the treatment and active control groups were similar in incidence, and all doses were well tolerated.

CONCLUSIONS

Intravitreal sirolimus 440 μg demonstrated a significant improvement in ocular inflammation with preservation of BCVA in subjects with active NIU of the posterior segment.

Current advances in the treatment of neovascular age-related macular degeneration

INTRODUCTION

Age-related macular degeneration (AMD) is the most common cause of permanent central visual acuity loss in persons over 65 years of age in industrialized nations. Today, intravitreal vascular endothelial growth factor (VEGF) inhibitors are the mainstay of treatment worldwide. Areas covered: The following review covers the current treatments and challenges of wet AMD management. It also covers emerging therapies including radiation, latest generation anti-VEGF agents, and combination therapies. Expert opinion: Current neovascular AMD therapy is aimed at decreasing the VEGF effect at the choroidal neovascularization (CNV) complex. The most important existing challenges in the treatment of neovascular AMD are improving visual outcomes, decreasing the treatment burden, and minimizing geographic atrophy. Clinicians are using many treatment strategies to minimize intravitreal injections without sacrificing visual outcomes. Combination of anti-VEGF therapy with other previously available treatments that target a different pathophysiological mechanism may be a reasonable clinical strategy to minimize intravitreal injections. Many exciting novel drugs that target newly discovered pathways associated with CNV development and progression hold clinical promise. The results of ongoing randomized clinical trials will answer the important concerns surrounding new drugs and delivery devices: safety and visual outcomes.

The Effect of Different Dosing Schedules of Intravitreal Sirolimus, a Mammalian Target of Rapamycin (mTOR) Inhibitor, in the Treatment of Non-Infectious Uveitis (An American Ophthalmological Society Thesis)

PURPOSE

To determine if two different doses of intravitreal sirolimus, an mTOR inhibitor, can decrease inflammation and is safe in eyes with non-infectious posterior, intermediate, or panuveitis in the Sirolimus as a Therapeutic Approach UVEitis: Protocol-2 (SAVE-2) Study.

METHODS

SAVE-2 is a prospective randomized, phase II, open-label interventional clinical trial conducted at 4 clinical centers in the United States. Eligible subjects were randomized into one of two treatments. Group 1 received 440µg of intravitreal sirolimus in study eyes on days 0, 30, 60, 90, 120, and 150; group 2 received 880µg of intravitreal sirolimus on days 0, 60, and 120. Fellow eyes were also eligible to receive sirolimus (of opposite dose to that of study eye). Primary endpoint of the study was at month 6 (M6).

RESULTS

24 subjects have been randomized in SAVE-2 and are included in the analysis. Vitreous haze decreased by ≥2 steps in 63.6% and 50% of patients in groups 1 and 2, respectively at M6 (p=0.695). Mean change in best-corrected visual acuity for subjects was +3.66 and -2.91 ETDRS letters in group 1 and 2, respectively. Among subjects with macular edema at baseline (n=13), the mean change in foveal thickness was -89.42µm in group 1 and +81.5µm in group 2 at M6.

CONCLUSIONS

Both low and high doses of intravitreal sirolimus were found to decrease vitreous haze in eyes with non-infectious uveitis. Low dose (440µg) sirolimus administered monthly may be more efficacious in reducing uveitic macular edema than high dose (880µg) administered every 2 months.

Sirolimus for the treatment of noninfectious uveitis

INTRODUCTION

Noninfectious posterior uveitis (NIPU) remains a significant burden of legal blindness. Because of its immune mediated and chronic recurrent nature, common therapy includes (systemic) corticosteroids and immune modulatory agents. Most treatments bear the risk of significant adverse effects. Therefore efforts are made to administer therapeutic agents directly into the vitreous cavity. The purpose of this article is to identify the role of intravitreally applied sirolimus as a recently approved therapeutic option in NIPU.

AREAS COVERED

A MEDLINE database search was conducted through August 2015 using the terms: intravitreal injection, pharmacology, sirolimus, treatment and uveitis. To provide ongoing and future perspectives in treatment options, also clinical trials as registered at ClinicalTrials.gov were included. Sirolimus (Opsiria) was in licensed from SANTEN in 2015 and approved in Phase III registration trials in the US, Europe and other countries for NIPU. Current information results mainly from registration and Phase III trials.

EXPERT OPINION

Intravitreal sirolimus appears to be an interesting option in the treatment algorithms of NIPU because of its highly targeted molecular effects, nonsteroidal nature and good safety profile. It has the advantage to avoid systemic side effects, but this has to be balanced against the fact that treatment covers one eye only and bears the risks of any intraocular procedure. Nevertheless a careful evaluation of this agent has to be made, as current experience is almost exclusively based on registration trials and long-term effects still have to be explored.

In Vitro and In Vivo Sustained Zero-Order Delivery of Rapamycin (Sirolimus) From a Biodegradable Intraocular Device

PURPOSE

We created implantable intraocular devices capable of constant and continuous rapamycin release on the scale of months to years.

METHODS

Polycaprolactone (PCL) thin films were used to encapsulate rapamycin to create implantable and biodegradable intraocular devices. Different film devices were studied by modifying the size, thickness, and porosity of the PCL films.

RESULTS

In vitro release of rapamycin was observed to be constant (zero-order) through 14 weeks of study. Release rates were tunable by altering PCL film porosity and thickness. In vivo release of rapamycin was observed out through 16 weeks with concentrations in the retina-choroid in the therapeutic range. Rapamycin concentration in the blood was below the lower limit of quantification. The drug remaining in the device was chemically stable in vitro and in vivo, and was sufficient to last for upwards of 2 years of total release. The mechanism of release is related to the dissolution kinetics of crystalline rapamycin.

CONCLUSIONS

Microporous PCL thin film devices demonstrate good ocular compatibility and the ability to release rapamycin locally to the eye over the course of many weeks.

Rapamycin ameliorates experimental autoimmune uveoretinitis by inhibiting Th1/Th2/Th17 cells and upregulating CD4+CD25+ Foxp3 regulatory T cells

AIM

To determine the effects of rapamycin on experimental autoimmune uveoretinitis (EAU) and investigate of role of rapamycin on T cell subsets in the disease.

METHODS

EAU was induced in rats using peptides 1169 to 1191 of the interphotoreceptor binding protein (IRBP). Rapamycin (0.2 mg/kg/d) was administrated by intraperitoneal injection for a consecutive 7d after immunization. Th1/Th2/Th17 cytokines, TGF-β1, and IL-6 produced by lymphocyteswere measured by ELISA, while Th17 cells and CD4+CD25+ regulatory T cells (Tregs) from rat spleen were detected by flow cytometry.

RESULTS

Intraperitoneal treatment immediately after immunization dramatically ameliorated the clinical course of EAU. Clinical responses were associated with reduced retinal inflammatory cell infiltration and tissue destruction. Rapamycin induced suppression of Th1/Th2/Th17 cytokines, including IFN-γ, IL-2, IL-17, IL-4, and IL-10 release from T lymphocytes of EAU rats, in vitro. Rapamycin also significantly increased TGF-β1 production but had no effect on IL-6 productionof T lymphocytes from EAU rats in vitro. Furthermore, rapamycin decreased the ratio of Th17 cells/CD4+T cells and upregulated Tregs in EAU, as detected by flow cytometry.

CONCLUSION

Rapamycin effectively interferes with T cell mediated autoimmune uveitis by inhibiting antigen-specific T cell functions and enhancing Tregs in EAU. Rapamycin is a promising new alternative as an adjunct corticosteroid-sparing agent for treating uveitis.

Subconjunctival sirolimus in the treatment of autoimmune non-necrotizing anterior scleritis: results of a phase I/II clinical trial

PURPOSE

To investigate the safety, tolerability and efficacy of subconjunctival sirolimus injections as a treatment for active, autoimmune, non-necrotizing anterior scleritis.

DESIGN

Phase I/II, single-center, open-label, nonrandomized, prospective pilot study.

METHODS

Five participants with active, autoimmune, non-necrotizing anterior scleritis with scleral inflammatory grade of ≥1+ in at least 1 quadrant with a history of flares were enrolled. A baseline injection was given, with the primary outcome measure of at least a 2-step reduction or reduction to grade zero in the study eye by 8 weeks. Secondary outcomes included changes in visual acuity and intraocular pressure, ability to taper concomitant immunosuppressive regimen, and number of participants who experienced a disease flare requiring reinjection. Safety outcomes included the number and severity of systemic and ocular toxicities, and vision loss ≥15 ETDRS letters. The study included 6 visits over 4 months with an extension phase to 1 year for participants who met the primary outcome.

RESULTS

All participants (N = 5, 100%; 95% CI [0.60, 1.00]) met the primary outcome in the study eye by the week 8 visit. There was no significant change in mean visual acuity or intraocular pressure. Three out of 5 patients (60%) experienced flares requiring reinjection. No systemic toxicities were observed. Two participants (40%) experienced a localized sterile inflammatory reaction at the site of the injection, which resolved without complication.

CONCLUSIONS

Subconjunctival sirolimus leads to a short-term reduction in scleral inflammation, though relapses requiring reinjection do occur. There were no serious adverse events, though a local sterile conjunctival inflammatory reaction was observed.

Surface engineering of porous silicon microparticles for intravitreal sustained delivery of rapamycin

PURPOSE

To understand the relationship between rapamycin loading/release and surface chemistries of porous silicon (pSi) to optimize pSi-based intravitreal delivery system.

METHODS

Three types of surface chemical modifications were studied: (1) pSi-COOH, containing 10-carbon aliphatic chains with terminal carboxyl groups grafted via hydrosilylation of undecylenic acid; (2) pSi-C12, containing 12-carbon aliphatic chains grafted via hydrosilylation of 1-dodecene; and (3) pSiO2-C8, prepared by mild oxidation of the pSi particles followed by grafting of 8-hydrocarbon chains to the resulting porous silica surface via a silanization.

RESULTS

The efficiency of rapamycin loading follows the order (micrograms of drug/milligrams of carrier): pSiO2-C8 (105 ± 18) > pSi-COOH (68 ± 8) > pSi-C12 (36 ± 6). Powder X-ray diffraction data showed that loaded rapamycin was amorphous and dynamic drug-release study showed that the availability of the free drug was increased by 6-fold (compared with crystalline rapamycin) by using pSiO2-C8 formulation (P = 0.0039). Of the three formulations in this study, pSiO2-C8-RAP showed optimal performance in terms of simultaneous release of the active drug and carrier degradation, and drug-loading capacity. Released rapamycin was confirmed with the fingerprints of the mass spectrometry and biologically functional as the control of commercial crystalline rapamycin. Single intravitreal injections of 2.9 ± 0.37 mg pSiO2-C8-RAP into rabbit eyes resulted in more than 8 weeks of residence in the vitreous while maintaining clear optical media and normal histology of the retina in comparison to the controls.

CONCLUSIONS

Porous silicon-based rapamycin delivery system using the pSiO2-C8 formulation demonstrated good ocular compatibility and may provide sustained drug release for retina.

Pharmacotherapy for uveitis: current management and emerging therapy

Uveitis, a group of conditions characterized by intraocular inflammation, is a major cause of sight loss in the working population. Most uveitis seen in Western countries is noninfectious and appears to be autoimmune or autoinflammatory in nature, requiring treatment with immunosuppressive and/or anti-inflammatory drugs. In this educational review, we outline the ideal characteristics of drugs for uveitis and review the data to support the use of current and emerging therapies in this context. It is crucial that we continue to develop new therapies for use in uveitis that aim to suppress disease activity, prevent accumulation of damage, and preserve visual function for patients with the minimum possible side effects.

Emerging therapies for noninfectious uveitis: what may be coming to the clinics

Corticosteroids along with other immunomodulatory therapies remain as the mainstay of treatment tor all patients with noninfectious uveitis (NIU). However, the systemic side effects associated with the long-term use of these drugs has encouraged the development of new therapeutic agents in recent times. This review article discusses upcoming therapeutic agents and drug delivery systems that are currently being used to treat patients with NIU. These agents mediate their actions by blocking specific pathways involved in the inflammatory process. Agents discussed in this review include full or recombinant monoclonal antibodies against interleukins such as IL-17 (secukinumab), IL-l (gevokizumab), and IL-6 (tocilizumab and sarilumab), antibody fragments against inflammatory cytokines such as TNF-α (ESBA 105) and T-cell inhibitors such as fusion proteins (abatacept), and next generation calcineurin inhibitors (voclosporin). In addition, administration of immune modulatory therapies using methods such as iontophoresis (EGP-437) and intravitreal injection (sirolimus) for the treatment of NIU' uveitis has also been discussed.

Review of Systemic Immunosuppression for Autoimmune Uveitis

The purpose of this review is to comprehensively examine the various therapeutic agents available to treat autoimmune eye disease, their indications, clinical safety and recent developments. The stepladder approach is reviewed, including corticosteroid administration of various forms, classic immunomodulators, and newer biologic response modifiers. The authors present that corticosteroid monotherapy is almost never curative and carries significant side effects, while immunomodulatory therapy, when used appropriately as way to induce steroid-free remission, carries far less risk of causing long-term complications and provides greater potential of altering the immune system to induce a durable remission.

Medical management of uveitis - current trends

Uveitis is a challenging disease to treat. Corticosteroids have been used in the treatment of uveitis for many years. Immunosuppressives are gaining momentum in recent years in the treatment of uveitis. In this article we present an overview of current treatment of uveitis and the major breakthroughs and advances in drugs and ocular drug delivery systems in the treatment of uveitis.

Systemic treatments for noninfectious vitreous inflammation

Vitreous inflammation, or vitritis, may result from many causes, including both infectious and noninfectious, including rheumatologic and autoimmune processes. Vitritis is commonly vision threatening and has serious sequelae. Treatment is frequently challenging, but, today, there are multiple methods of systemic treatment for vitritis. These categories include corticosteroids, antimetabolites, alkylating agents, T-cell inhibitors/calcineurin inhibitors, and biologic agents. These treatment categories were reviewed last year, but, even over the course of just a year, many therapies have made progress, as we have learned more about their indications and efficacy. We discuss here discoveries made over the past year on both existing and new drugs, as well as reviewing mechanisms of action, clinical dosages, specific conditions that are treated, adverse effects, and usual course of treatment for each class of therapy.

Treatment of geographic atrophy with subconjunctival sirolimus: results of a phase I/II clinical trial

PURPOSE

To investigate the safety and effects of subconjunctival sirolimus, an mTOR inhibitor and immunosuppressive agent, for the treatment of geographic atrophy (GA).

METHODS

The study was a single-center, open-label phase II trial, enrolling 11 participants with bilateral GA; eight participants completed 24 months of follow-up. Sirolimus (440 μg) was administered every 3 months as a subconjunctival injection in only one randomly assigned eye in each participant for 24 months. Fellow eyes served as untreated controls. The primary efficacy outcome measure was the change in the total GA area at 24 months. Secondary outcomes included changes in visual acuity, macular sensitivity, central retinal thickness, and total drusen area.

RESULTS

The study drug was well tolerated with few symptoms and related adverse events. Study treatment in study eyes was not associated with structural or functional benefits relative to the control fellow eyes. At month 24, mean GA area increased by 54.5% and 39.7% in study and fellow eyes, respectively (P = 0.41), whereas mean visual acuity decreased by 21.0 letters and 3.0 letters in study and fellow eyes, respectively (P = 0.03). Substantial differences in mean changes in drusen area, central retinal thickness, and macular sensitivity were not detected for all analysis time points up to 24 months.

CONCLUSIONS

Repeated subconjunctival sirolimus was well-tolerated in patients with GA, although no positive anatomic or functional effects were identified. Subconjunctival sirolimus may not be beneficial in the prevention of GA progression, and may potentially be associated with effects detrimental to visual acuity. (ClinicalTrials.gov number, NCT00766649.).

Ocular tolerability and efficacy of intravitreal and subconjunctival injections of sirolimus in patients with non-infectious uveitis: primary 6-month results of the SAVE Study

BACKGROUND

The purpose of this study is to evaluate the ocular tolerability and efficacy of sirolimus administered as subconjunctival or intravitreal injections in patients with non-infectious uveitis. Sirolimus as a Therapeutic Approach for Uveitis (SAVE) is a prospective, randomized, open-label, interventional study. Thirty patients were enrolled and randomized in 1:1 ratio to receive either intravitreal injections of 352 μg sirolimus or subconjunctival injections of 1,320 μg at days 0, 60, and 120, with primary endpoint at month 6.

RESULTS

At month 6, all subjects with active uveitis at baseline showed reduction in vitreous haze of one or more steps. Forty percent of subjects showed reduction of two steps or more of vitreous haze (four in each group), and 60% showed a reduction of one-step vitreous haze (seven in group 1 and five in group 2). Changes in the inflammatory indices were statistically significant (p < 0.05) in both study groups. Thirty percent of patients gained one or more lines of visual acuity, 20% lost one or more lines, and 50% maintained the same visual acuity. There were no statistically significant differences between the two study groups at month 6. No serious adverse events were found to be related to the study drug.

CONCLUSION

Local administration of sirolimus, either intravitreally or subconjunctivally, appears to be safe and tolerable. No drug-related systemic adverse events or serious adverse events were noted. Sirolimus delivered as either an intravitreal or subconjunctival injection has demonstrated bioactivity as an immunomodulatory and corticosteroid-sparing agent in reducing vitreous haze and cells, improving visual acuity, and in decreasing the need for systemic corticosteroids.

Think global--act local: intravitreal drug delivery systems in chronic noninfectious uveitis

The eye is probably the most attractive site of the body for treatment using locally delivered therapeutic agents. An ideal indication for such an approach is noninfectious posterior uveitis. Since intraocular structures of the posterior segment are difficult to reach and are otherwise accessible only by systemic treatment, current interest is focused on the pros and cons of intravitreal drug delivery. Because of its chronic and recurrent nature, the long-term release of anti-inflammatory agents is a major treatment goal. Intravitreal injections, intravitreal implants and biodegradable devices are the most commonly used and approved approaches to deliver various agents to the vitreous. Because of their broad and potent effects, corticosteroids (CS) have been the first-line candidates for intraocular delivery. An increasing spectrum of CS preparations including nondegradable and biodegradable devices is currently available. Since repeated and long-term applications bear the risk of steroid-related complications such as increased intraocular pressure and cataract, alternative agents are currently being tested. Intravitreal injection of methotrexate, anti-VEGF (vascular endothelial growth factor), anti-TNFα (tumor necrosis factor α) and sirolimus have also been applied in patients with conflicting results. Intravitreal treatment has significantly reduced the incidence of adverse effects compared to systemic application, but due to greater ocular side effects there are still some limitations.

Everolimus for the treatment of uveitis refractory to cyclosporine A: a pilot study

BACKGROUND

This study investigated the efficacy of everolimus, a potent inhibitor of T lymphocyte proliferation, for treating noninfectious uveitis. The study design was an open-label prospective trial.

METHODS

Twelve patients with severe chronic uveitis (anterior and intermediate n = 9, panuveitis n = 3) refractive to cyclosporine A (CsA) received additional everolimus.

MAIN OUTCOME MEASURE

the primary outcome measure was uveitis inactivity at 3 months. Secondary outcome measures were uveitis recurrence, visual acuity (BCVA), laser flare photometry values, cystoid macular edema, and tapering of concomitant corticosteroids and/or immunosuppressive drugs in 12 months with the addition of everolimus and after withdrawing everolimus. Percentages of peripheral blood CD3(+)CD4(+)CD25(+)Foxp3(+) cells were studied.

RESULTS

At month 3 with everolimus, uveitis was inactive in all patients. By 12 months, uveitis had recurred in four patients after tapering (n = 2) or withdrawing (n = 2) CsA. BCVA remained stable in all patients, mean foveal thickness (OCT) was slightly reduced from 308 μm at baseline to 255 μm (p = 0.1), and mean flare values were slightly reduced from 27.8 to 19.3 photons/msec (p = 0.1). It was possible to achieve a 50 % dose reduction of systemic prednisone (n = 8) or CsA (n = 8). After withdrawing everolimus, uveitis recurred in 50 % within 1 month; by 6 months, BCVA dropped ≥2 lines in five patients, and prednisone use increased ≥50 % in four patients. The percentage of peripheral blood CD3(+)CD4(+)CD25(+)FoxP3(+) T cells increased during the everolimus treatment, and dropped after withdrawal.

CONCLUSIONS

Uveitis inactivity was achieved with the addition of everolimus in patients with chronic, CsA-refractive anterior and intermediate uveitis, or panuveitis.

Systemic treatment of vitreous inflammation

Non infectious vitreous inflammation is often vision threatening and can be associated with potentially life-threatening systemic conditions. Treatment is often challenging as it involves systemic medications that can be associated with adverse effects. The classes of drugs are ever expanding and include corticosteroids, antimetabolites, alkylating agents, T-cell and calcineurin agents, biologic agents, and interferons. Each class of systemic therapy for non-infectious vitreous inflammation is reviewed. We discuss the mechanisms of action, usual clinical dosages, the specific conditions that are treated, the adverse effects, and usual course of treatment for each class of therapy.

Subconjunctival sirolimus for the treatment of chronic active anterior uveitis: results of a pilot trial

PURPOSE

To evaluate the safety and possible efficacy of subconjunctival sirolimus for the treatment of chronic active anterior uveitis.

DESIGN

Prospective, nonrandomized, open-label clinical trial.

METHODS

This single-center pilot trial enrolled 5 patients with chronic active anterior uveitis. The study drug was administered as a single subconjunctival injection of 30 μL (1320 μg) sirolimus in the study eye at the baseline visit. Study visits were performed at baseline, at 2 weeks, at 4 weeks, and monthly until 4 months, and included a complete ophthalmic examination, review of systems, adverse event assessment at each visit, physical examination, and ancillary ophthalmic testing at some visits. The primary outcome measure was a 2-step reduction in the anterior chamber inflammation within 4 weeks of injection of the study drug.

RESULTS

There were 3 female and 2 male patients; 4 patients had idiopathic anterior uveitis and 1 had psoriatic arthritis-associated anterior uveitis. Three of the 5 patients met the primary outcome criteria by showing at least a 2-step decrease in inflammation within 4 weeks; 2 patients showed a 1-step decrease in inflammation within the same time frame. No recurrence was encountered during a 4-month follow-up. There were no serious adverse events.

CONCLUSIONS

Subconjunctival sirolimus appears to be well tolerated in this pilot trial and shows promise as a treatment for active inflammation in patients with chronic anterior uveitis. Larger studies are needed to assess its usefulness in uveitis.

Recent Patents on Emerging Therapeutics for the Treatment of Glaucoma, Age Related Macular Degeneration and Uveitis

Advancements in the field and rising interest among pharmaceutical researchers have led to the development of new molecules with enhanced therapeutic activity. Design of new drugs which can target a particular pathway and/or explore novel targets is of immense interest to ocular pharmacologists worldwide. Delivery of suitable pharmacologically active agents at proper dose (within the therapeutic window) to the target tissues without any toxicity to the healthy ocular tissues still remain an elusive task. Moreover, the presence of static and dynamic barriers to drug absorption including the corneal epithelium (lipophilic), corneal and scleral stroma (hydrophilic), conjunctival lymphatics, choroidal vasculature and the blood-ocular barriers also pose a significant challenge for achieving therapeutic drug concentrations at the target site. Although many agents are currently available, new compounds are being introduced for treating various ocular diseases. Deeper understanding of the etiology and complex mechanisms associated with the disease condition would aid in the development of potential therapeutic candidates. Novel small molecules as well as complex biotechnology derived macromolecules with superior efficacy, safety and tolerability are being developed. Therefore, this review article provides an overview of existing drugs, treatment options, advances in emerging therapeutics and related recent patents for the treatment of ocular disorders such as glaucoma, age related macular degeneration (AMD) and uveitis.

Road to remission: a comprehensive review of therapy in uveitis

INTRODUCTION

Although uveitis remains the third leading cause of preventable blindness in the US, the care and management of patients with uveitis and ocular inflammatory disease sit poised to make evolutionary if not revolutionary changes in the years ahead. This review serves to highlight important advances in the pharmacologic options available for the treatment of uveitis and ocular inflammation.

AREAS COVERED

Advances in steroid therapy (both topical and extended delivery), updates in the clinical safety of systemic immune modulation, and the emerging therapies for uveitis and ocular inflammatory disease are some of the areas covered in this review.

EXPERT OPINION

Corticosteroids have been the mainstay in the care of patients with ocular inflammatory disorders for many years. Indeed, some physicians still use only steroids for treating inflamed eyes. However, the mission is remission of all corticosteroids in order to prevent the complications associated with long-term corticosteroid use. The goal is to achieve quiescence through aggressive use of corticosteroids to extinguish the fire and then move along to achieve steroid-free remission through immunosuppressant agents.

Emerging drugs for uveitis

INTRODUCTION

Uveitis is a challenging disease covering both infectious and noninfectious conditions. The current treatment strategies are hampered by the paucity of randomized controlled trials and trials comparing the efficacy of different agents.

AREAS COVERED

This review describes the current and future treatments of uveitis. A literature search was performed in PUBMED from 1965 to 2010 on drugs treating ocular inflammation with emphasis placed on more recent, larger studies. Readers should gain a basic understanding of current treatment strategies beginning with corticosteroids and transitioning to steroid sparing agents. Steroid sparing agents include antimetabolites such as methotrexate, azathioprine and mycophenolate mofetil; calcineurin inhibitors which include cyclosporine, tacrolimus; alkylating agents which include cyclophosphamide and chlorambucil; and biologics which include the TNF-α inhibitors infliximab, adalimumab and etanercept and daclizumab, IFN-α(2a) and rituximab.

EXPERT OPINION

Newer agents are typically formulated from existing drugs or developed based on new advances in immunology. Future treatment will require a better understanding of the mechanisms involved in autoimmune diseases and better delivery systems in order to provide targeted treatment with minimal side effects.