Effect of OTX-101, a Novel Nanomicellar Formulation of Cyclosporine A, on Conjunctival Staining in Patients with Keratoconjunctivitis Sicca: A Pooled Analysis of Phase 2b/3 and 3 Clinical Trials

Selective Pharmacologic Therapies for Dry Eye Disease Treatment: Efficacy, Tolerability, and Safety Data Review from Preclinical Studies and Pivotal Trials

Keratoconjunctivitis sicca, also known as dry eye disease (DED), is a prevalent, multifactorial disease associated with compromised ocular lubrication, ocular surface inflammation and damage, and ocular symptoms. Several anti-inflammatory, topical ophthalmic therapies are available to treat clinical signs and symptoms of DED in the USA and Europe. Cyclosporine A (CsA)-based formulations include an ophthalmic emulsion of 0.05% CsA (CsA 0.05%), a cationic emulsion (CE) of CsA 0.1% (CsA CE), and an aqueous nanomicellar formulation of 0.09% CsA (OTX-101). Lifitegrast is a 5% ophthalmic solution of a lymphocyte function-associated antigen 1 antagonist that is believed to target T cell activation and recruitment to inhibit ocular inflammation. Here we provide a comprehensive review summarising preclinical studies and pivotal trial data for these treatments to provide a complete understanding of their efficacy and safety profile. Overall, data in the evaluated studies show a favourable risk-benefit profile for the use of targeted topical anti-inflammatory pharmacologic treatments in patients with DED. Pivotal trials for CsA 0.05%, CsA CE, OTX-101, and lifitegrast clearly demonstrate treatment efficacy compared to vehicle across treatments with no serious ocular treatment-emergent adverse events (TEAEs). Patients using ophthalmic treatments reported ocular TEAEs more frequently than those treated with vehicle; however, relatively few TEAEs led to treatment discontinuation. The specific signs and symptoms of DED that improve with treatment vary with the treatment prescribed. Long-term and direct comparative studies between treatments are needed to further understand treatment differences in efficacy and safety profiles.

Posaconazole micelles for ocular delivery: in vitro permeation, ocular irritation and antifungal activity studies

Posaconazole (PSC) is a triazole group anti-fungal agent with the widest spectrum. Although there is no commercially available ocular dosage form, its diluted oral suspension preparation (Noxafil®) is used as off-label in topical treatment of severe keratitis and sclerokeratitis in the clinic. However, ocular bioavailability of PSC suspension form is extremely low due to its highly lipophilic character. Thus, there is a clinical need to improve its ocular bioavailability and to develop novel delivery system for the treatment of ocular fungal infections. Herein, we studied ex vivo permeation, penetration, anti-fungal activity, and Hen's Egg Test-Chorioallantoic Membrane (HET-CAM) toxicity tests in order to assess ocular targeting of PSC micelles, which were optimized in our previous study. The results indicated that micellar carrier system increased the permeability of PSC to eye tissues. Micelles showed higher affinity to ocular tissues than that of commercial oral suspension of PSC (Noxafil®). In vitro anti-fungal activity data also confirmed the efficacy of PSC loaded micellar formulations against Candida. albicans strains. The relative safety of the optimized micelles on the ocular tissue was shown with the HET-CAM toxicity test. In conclusion, micellar systems could be a promising strategy for the effective and safe delivery of PSC in the treatment of ocular fungal infections.

Optimization of the Micellar-Based In Situ Gelling Systems Posaconazole with Quality by Design (QbD) Approach and Characterization by In Vitro Studies

Background: Fungal ocular infections can cause serious consequences, despite their low incidence. It has been reported that Posaconazole (PSC) is used in the treatment of fungal infections in different ocular tissues by diluting the oral suspension, and successful results were obtained despite low ocular permeation. Therefore, we optimized PSC-loaded ocular micelles and demonstrated that the permeation/penetration of PSC in ocular tissues was enhanced. Methods: The micellar-based in situ gels based on the QbD approach to increase the ocular bioavailability of PSC were developed. Different ratios of Poloxamer 407 and Poloxamer 188 were chosen as CMAs. Tsol/gel, gelling capacity and rheological behavior were chosen as CQA parameters. The data were evaluated by Minitab 18, and the formulations were optimized with the QbD approach. The in vitro release study, ocular toxicity, and anti-fungal activity of the optimized formulation were performed. Results: Optimized in situ gel shows viscoelastic property and becomes gel form at physiological temperatures even when diluted with the tear film. In addition, it has been shown that the formulation had high anti-fungal activity and did not have any ocular toxicity. Conclusions: In our previous studies, PSC-loaded ocular micelles were developed and optimized for the first time in the literature. With this study, the in situ gels of PSC for ocular application were developed and optimized for the first time. The optimized micellar-based in situ gel is a promising drug delivery system that may increase the ocular permeation and bioavailability of PSC.

The Effect of OTX-101 on Tear Production in Patients with Severe Tear-deficient Dry Eye Disease: A Pooled Analysis of Phase 2b/3 and Phase 3 Studies

PURPOSE

Impaired tear production - a common sign of keratoconjunctivitis sicca (KCS) - is associated with qualitative or quantitative tear deficiency. OTX-101 0.09% is a novel, nanomicellar formulation of cyclosporine A approved in the US for increasing tear production in patients with KCS. We present a pooled analysis of the phase 2b/3 and phase 3 studies evaluating the effect of OTX-101 on tear production in a subgroup of patients with keratoconjunctivitis sicca with severely impaired tear production (Schirmer's score <5 mm in either eye at baseline).

METHODS

In these randomized, double-masked studies, patients instilled 1 drop OTX-101 or vehicle per eye twice daily for 84 days. Pooled efficacy endpoints included percent (%) of patients with ≥10 mm change from baseline and mean change from baseline in Schirmer's score at day 84. Pooled safety endpoints included adverse event monitoring.

RESULTS

Subgroup analyses included 133 and 113 patients receiving OTX-101 and vehicle, respectively. Mean baseline (BL) Schirmer's score ± standard deviation was 2.7 ± 1.2 for OTX-101 and 2.5 ± 1.1 mm for vehicle (P = .3203). On day 84, number (%) of patients with ≥10 mm Schirmer's score change from baseline was 30 (22.6%) and 12 (10.6%, P = .0168); mean change from baseline ± standard deviation was 5.5 ± 8.0 and 3.6 (6.0, P = .0405) mm for OTX-101 and vehicle, respectively. Adverse events were mostly mild and did not require treatment.

CONCLUSION

OTX-101 administered twice daily for 84 days significantly improved tear production vs vehicle in patients with severely impaired tear production, as evidenced by significantly larger proportion of patients with ≥10 mm increases from baseline and higher mean change from baseline in Schirmer's scores.

Phase 3 Efficacy (Worse-Eye Analysis) and Long-Term Safety Evaluation of OTX-101 in Patients with Keratoconjunctivitis Sicca

Background

OTX-101 is approved for treatment of keratoconjunctivitis sicca (KCS). We present results of a phase 3 worse-eye efficacy analysis and 1-year safety extension.

Methods

During the double-masked treatment phase, patients with bilateral KCS were randomized 1:1 to 12 weeks OTX-101 or vehicle 1 drop per eye twice daily. Efficacy assessments included Schirmer’s test and corneal and conjunctival staining. All patients who completed the treatment phase were eligible for enrollment in the open-label extension and received 1 drop OTX-101 twice daily for up to 52 weeks. Safety endpoints included adverse event (AE) monitoring, Snellen visual acuity (VA), intraocular pressure (IOP), slit-lamp examination (SLE), and dilated fundoscopy.

Results

Overall, 745 and 258 patients enrolled in the treatment and safety extension phases, respectively. At 12 weeks, number (%) of patients with Schirmer’s score increase of ≥10 mm from baseline was 76 (20.5%) vs. 42 (11.3%) for OTX-101 vs. vehicle (P=0.0005). OTX-101 significantly improved total conjunctival staining vs. vehicle at week 12 (least squares mean change from baseline −1.65 [0.12] vs. −1.12 [0.12], P=0.0013), and number (%) of patients with clear central corneas vs. vehicle at week 12 (222 [64.0%] vs. 199 [55.3%], P=0.0179). In the 1-year safety extension, AEs were mostly mild; instillation site pain was most common in 59 (22.9%) patients (17 [13.2%] vs. 42 [32.6%] patients receiving prior OTX-101 and vehicle). No safety concerns were raised by VA, IOP, SLE, and fundoscopy.

Conclusion

OTX-101 efficacy was confirmed in the eye with lower baseline Schirmer’s score. OTX-101 was well tolerated long term.

Clinical Trial

Registered at ClinicalTrials.gov on July 27, 2016. NCT02845674 https://clinicaltrials.gov/ct2/show/NCT02845674?term=OTX-101&draw=2&rank=1.

A Review of the Mechanism of Action of Cyclosporine A: The Role of Cyclosporine A in Dry Eye Disease and Recent Formulation Developments

Dry eye disease (DED) is a multifactorial disease of the ocular surface and tear film that has gained awareness as a public health problem. Characteristics of DED include tear film instability, hyperosmolarity, and ocular surface inflammation, which can occur independently or may be a sequela of numerous ocular diseases, ocular surgery or contact lens wear. Much has been learned about the impact of the disease to help affected individuals who report symptoms of poor vision, pain, and tearing. Recently, new research highlights the importance of the role of ocular surface inflammation and damage in DED-leading to a vicious cycle of inflammation as well as loss of tear film homeostasis. DED immunopathophysiology is characterized by four stages: initiation, amplification, recruitment, and re-initiation. Cyclosporine is proven to be a valuable ophthalmic therapeutic for DED through its immunomodulatory actions and regulation of the adaptive immune response. Cyclosporine mechanism of action is well described in the published literature and the myriad of benefits in all four stages lend a broad-based immunomodulatory function particularly suitable for addressing DED. Furthermore, cyclosporine has unique goblet cell density improvement capabilities as well as anti-apoptotic properties. Topical formulations of cyclosporine are centered around addressing the highly lipophilic nature of the molecule. The poor aqueous solubility of cyclosporine traditionally presented technical challenges in drug delivery to the ocular surface. Newer formulations such as cationic emulsions and nanomicellar aqueous solutions address formulation, tissue concentration, and drug delivery challenges.

Prodrugs and nanomicelles to overcome ocular barriers for drug penetration

INTRODUCTION

Ocular barriers hinder drug delivery and reduce drug bioavailability. This article focuses on enhancing drug absorption across the corneal and conjunctival epithelium. Both, transporter targeted prodrug formulations and nanomicellar strategy is proven to enhance the drug permeation of therapeutic agents across various ocular barriers. These strategies can increase aqueous drug solubility and stability of many hydrophobic drugs for topical ophthalmic formulations.

AREAS COVERED

The article discusses various ocular barriers, ocular influx, and efflux transporters. It elaborates various prodrug strategies used for enhancing drug absorption. Along with this, the article also describes nanomicellar formulation, its characteristic and advantages, and applications in for anterior and posterior segment drug delivery.

EXPERT OPINION

Prodrugs and nanomicellar formulations provide an effective strategy for improving drug absorption and drug bioavailability across various ocular barriers. It will be exciting to see the efficacy of nanomicelles for treating back of the eye disorders after their topical application. This is considered as a holy grail of ocular drug delivery due to the dynamic and static ocular barriers, restricting posterior entry of topically applied drug formulations.

Micelles: Promising Ocular Drug Carriers for Anterior and Posterior Segment Diseases

Micelles have been studied in the targeting of drug substances to different tissues as a nano-sized delivery system for many years. Sustained drug release, ease of production, increased solubility, and bioavailability of drugs with low water solubility are the most important superiorites of micellar carriers. These advantages paved the way for the use of micelles as a drug delivery system in the ocular tissues. The unique anatomical structure of the eye as well as its natural barriers and physiology affect ocular bioavailability of the drugs negatively. Conventional dosage forms can only reach the anterior segment of the eye and are used for the treatment of diseases of this segment. In the treatment of posterior segment diseases, conventional dosage forms are administered sclerally, via an intravitreal injection, or systemically. However, ocular irritation, low patient compliance, and high side effects are also observed. Micellar ocular drug delivery systems have significant promise for the treatment of ocular diseases. The potential of micellar systems ocular drug delivery has been demonstrated by in vivo animal experiments and clinical studies, and they are continuing extensively. In this review, the recent research studies, in which the positive outcomes of micelles for ocular targeting of drugs for both anterior and posterior segment diseases as well as glaucoma has been demonstrated by in vitro, ex vivo, or in vivo studies, are highlighted.

A Review of Topical Cyclosporine A Formulations-A Disease-Modifying Agent for Keratoconjunctivitis Sicca

Keratoconjunctivitis sicca (KCS) is a multifactorial disease characterized by tear hyperosmolarity, inflammation, and ocular surface damage. Cyclosporine A (CsA) is used as an effective disease-modifying agent to improve the signs and symptoms of KCS by reducing inflammation, which interferes with tear production. This review provides an overview of efficacy, safety, and limitations of currently marketed topical CsA formulations—including CsA ophthalmic emulsion, cationic nanoemulsion, and aqueous nanomicelles—and highlights newer technologies for controlled ocular delivery of CsA and their clinical implications. Long available emulsion formulations of CsA are oil-based and have several limitations, including slow onset of efficacy and low intraocular penetration and bioavailability. Aqueous CsA nanomicelle carriers produce rapid improvement in objective signs of KCS such as corneal and conjunctival staining as early as 4 weeks and have acceptable safety profiles. CsA formulations using semifluorinated alkanes or polyaphrons are currently in clinical development, having recently completed Phase 2 studies. Other carriers for CsA currently in the preclinical phase include microemulsions, polymeric aqueous and lyophilized micelles, and hydrogels; these novel formulations have yet to undergo clinical trials. Formulations that improve tissue availability of CsA may be beneficial in clinical practice by providing faster onset of relief and improving patient adherence.