Safety and efficacy of twice daily administration of KPI-121 1% for ocular inflammation and pain following cataract surgery

Recent advances in nanocrystal-based technologies applied for ocular drug delivery

INTRODUCTION

The intricate physiological barriers of the eye and the limited volume of eye drops impede efficient delivery of poorly water-soluble drugs. In the last decade, nanocrystals have emerged as versatile drug delivery systems in various administration routes from bench to bedside. The unique superiorities of nanocrystals, mainly embodied in high drug-loading capacity, good mucosal adhesion and penetration, and greatly improved drug solubility, reveal a promising prospect for ocular delivery of poorly water-soluble drugs.

AREAS COVERED

This article focuses on the ophthalmic nanocrystal technologies and products that are in the literature, clinical trials, and even on the market. The recent research progress in the preparation, ocular application, and absorption of nanocrystals are highlighted, and the pros and cons of nanocrystals in overcoming the physiological barriers of the eye are also summarized.

EXPERT OPINION

Nanocrystals have demonstrated success as glucocorticoid eye drops in the treatment of anterior segment diseases. However, the thermodynamic stability of nanocrystals remains the major challenge in product development. New technologies for efficiently optimizing stabilizers and sterilization processes are still expected. Strategies to confer more diverse functions via surface modification are also worth exploration to improve the potential of nanocrystals in delivering poorly water-soluble drugs to posterior segment of the eye.

Progress in Ocular Drug Delivery: Challenges and Constraints

The eye has several dynamic and static barriers in place to limit the entry of foreign substances including therapeutics. As such, efficient drug delivery, especially to posterior segment tissues, has been challenging. This chapter describes the anatomical and physiological challenges associated with ocular drug delivery before discussing constraints with regard to formulation parameters. Finally, it gives an overview of advanced drug delivery technologies with a specific focus on recently marketed and late-stage clinical trial products.

0.2% Betamethasone Sodium Phosphate: A Multicenter, Randomized, Double-Masked Study to Compare Its Ocular Safety, Tolerability, and Efficacy to Vehicle in Cataract Surgery Subjects

Purpose

To compare the preservative-free corticosteroid 0.2% betamethasone sodium phosphate BID (SURF-201) to vehicle BID in patients undergoing routine cataract surgery.

Methods

Phase 2, multicenter, randomized (1:1 ratio), double-masked, vehicle-controlled, parallel-group study in patients scheduled for uncomplicated cataract surgery without the aid of a femtosecond laser. Subjects instilled topical medications for 16 days beginning the day before cataract surgery (Day -1), 1 dose administered at least 1 hour prior to cataract surgery (on Day 0) and 1 dose on the evening after cataract surgery, and then 2 doses administered each day through Day 15; patients were re-evaluated on Days 22 and 32 to ensure no rebound inflammation. Primary outcome was the difference in the proportion of subjects with anterior chamber cell (ACC) grade 0 between the two groups at Day 15. Secondary outcomes included pain scores and overall safety.

Results

There was a statistically significant difference (P=0.004) in the proportion of subjects in the SURF-201 treatment group with an ACC grade of 0 at Day 15 (n=22/39 [56.4%]) compared to subjects in the vehicle treatment group (n=9/43 [20.9%]). There was no statistically significant difference (P=0.528) in the proportion of subjects in the SURF-201 treatment group who had a visual analog scale pain score of 0 at Day 15 (n=35/38 [89.7%]) compared to subjects in the vehicle group (n=33/40 [82.5%]). A slightly higher incidence of adverse events occurred in subjects in the SURF-201 treatment group (n=27/40 [67.5%]) compared to the vehicle treatment group (n=23/43 [53.5%]).

Conclusion

SURF-201 is an effective topical, preservative-free corticosteroid when dosed BID for the treatment of postoperative inflammation and prevention of pain in a post-cataract population.

Nanotechnology-based ocular drug delivery systems: recent advances and future prospects

Ocular drug delivery has constantly challenged ophthalmologists and drug delivery scientists due to various anatomical and physiological barriers. Static and dynamic ocular barriers prevent the entry of exogenous substances and impede therapeutic agents' active absorption. This review elaborates on the anatomy of the eye and the associated constraints. Followed by an illustration of some common ocular diseases, including glaucoma and their current clinical therapies, emphasizing the significance of drug therapy in treating ocular diseases. Subsequently, advances in ocular drug delivery modalities, especially nanotechnology-based ocular drug delivery systems, are recommended, and some typical research is highlighted. Based on the related research, systematic and comprehensive characterizations of the nanocarriers are summarized, hoping to assist with future research. Besides, we summarize the nanotechnology-based ophthalmic drugs currently on the market or still in clinical trials and the recent patents of nanocarriers. Finally, inspired by current trends and therapeutic concepts, we provide an insight into the challenges faced by novel ocular drug delivery systems and further put forward directions for future research. We hope this review can provide inspiration and motivation for better design and development of novel ophthalmic formulations.

Dry Eye Disease Associated with Meibomian Gland Dysfunction: Focus on Tear Film Characteristics and the Therapeutic Landscape

Meibomian gland dysfunction (MGD) is highly prevalent and is the leading cause of evaporative dry eye disease (DED). MGD is characterized by a reduction in meibum secretion and/or a change in meibum composition that results in the disruption of the tear film lipid layer and an increase in the tear film evaporation rate. Excessive evaporation causes tear film instability, desiccation, tear hyperosmolarity, inflammation, and apoptosis of ocular surface cells, resulting in a continuous cycle of DED. The primary treatment goal for DED associated with MGD is to restore the tear film lipid layer and decrease evaporation, thereby reducing ocular signs and symptoms. The management of MGD includes home care options (eyelid hygiene, warming eye masks, ocular lubricants) and office-based treatments (manual expression, microblepharoexfoliation, thermal pulsation, intense pulsed light, intraductal probing). Topical ophthalmic prescription medications attempt to alter various factors that may contribute to DED (e.g., inflammation, bacterial growth, inadequate tear production). In this review, clinical evidence regarding available treatments and emerging therapies from randomized studies in patients with DED associated with MGD is summarized. Although some treatment modalities have been evaluated specifically for DED patients with MGD, large-scale randomized controlled trials are needed to confirm efficacy and safety in this patient population. Currently, there are no approved prescription pharmacologic treatments specifically indicated for DED associated with MGD, and those medications approved for the treatment of DED do not target the key driver of the disease (i.e., excessive evaporation). NOV03 (perfluorohexyloctane; under review with the US Food and Drug Administration) is the most advanced emerging therapy for DED associated with MGD and has demonstrated statistically significant improvements in both signs and symptoms in randomized controlled trials. Development of novel pharmacotherapies will improve therapeutic options and allow for a more individualized approach for patients with DED associated with MGD.

Topical phenylbutyrate antagonizes NF-κB signaling and resolves corneal inflammation

Chronic inflammation of the immune privileged cornea originating from viral or nonviral conditions results in significant vision loss. Topical corticosteroids are the common treatments for corneal inflammation, but the drugs cause serious and potentially blinding side effects in the long term. Therefore, new standalone and/or synergistic anti-inflammatory therapies with lower side effects are desperately needed. Here, we show that the aromatic fatty acid phenylbutyrate (PBA) acts as a potent inhibitor of inflammation in preclinical ocular-inflammation models. PBA prevents the transcription as well as translation of pro-inflammatory cytokines by LPS and poly(I:C) via persistent inhibition of NF-κB signaling. PBA quickens the resolution of ocular inflammation in mice by decreasing corneal thickness and immune cell infiltration. More importantly, PBA can synergize with the dexamethasone to antagonize NF-κB signaling at lower drug concentrations. Our results demonstrate that PBA therapy exerts previously unreported anti-inflammatory effects in the eye and facilitates corneal healing during persistent inflammation.

Ocular Nanomedicine

Intrinsic shortcomings associated with conventional therapeutic strategies often compromise treatment efficacy in clinical ophthalmology, prompting the rapid development of versatile alternatives for satisfactory diagnostics and therapeutics. Given advances in material science, nanochemistry, and nanobiotechnology, a broad spectrum of functional nanosystems has been explored to satisfy the extensive requirements of ophthalmologic applications. In the present review, the recent progress in nanosystems, both conventional and emerging nanomaterials in ophthalmology from state-of-the-art studies, are comprehensively examined and the role of their fundamental physicochemical properties in bioavailability, tissue penetration, biodistribution, and elimination after interacting with the ophthalmologic microenvironment emphasized. Furthermore, along with the development of surface engineering of nanomaterials, emerging theranostic methodologies are promoted as potential alternatives for multipurpose ocular applications, such as emerging biomimetic ophthalmology (e.g., smart electrochemical eye), thus provoking a holistic review of "ocular nanomedicine." By affording insight into challenges encountered by ocular nanomedicine and further highlighting the direction of future studies, this review provides an incentive for enriching ocular nanomedicine-based fundamental research and future clinical translation.

Practical Guidance for the Use of Loteprednol Etabonate Ophthalmic Suspension 0.25% in the Management of Dry Eye Disease

Dry eye disease (DED) is a prevalent ocular surface disease. Like with any chronic disease, patients with DED can experience episodic flares. There are many existing and upcoming treatments for the chronic treatment of DED, yet treatments for DED flares are limited. Loteprednol etabonate 0.25% is an FDA approved treatment modality for the short-term treatment of the signs and symptoms of DED. This medication is formulated with the customized mucus-penetrating particle (MPP) technology, which has a greater ability to penetrate the ocular surface and more effectively deliver the active steroid to the ocular surface tissues as compared with conventional steroid preparations. There is also increasing utility of loteprednol etabonate 0.25% in the treatment of DED before and/or after cataract or refractive surgery or as induction therapy prior to starting chronic immunomodulatory medication for DED.

Nanotechnology for Topical Drug Delivery to the Anterior Segment of the Eye

Topical drug delivery is one of the most challenging aspects of eye therapy. Eye drops are the most prevalent drug form, especially for widely distributed anterior segment eye diseases (cataracts, glaucoma, dry eye syndrome, inflammatory diseases, etc.), because they are convenient and easy to apply by patients. However, conventional drug formulations are usually characterized by short retention time in the tear film, insufficient contact with epithelium, fast elimination, and difficulties in overcoming ocular tissue barriers. Not more than 5% of the total drug dose administered in eye drops reaches the interior ocular tissues. To overcome the ocular drug delivery barriers and improve drug bioavailability, various conventional and novel drug delivery systems have been developed. Among these, nanosize carriers are the most attractive. The review is focused on the different drug carriers, such as synthetic and natural polymers, as well as inorganic carriers, with special attention to nanoparticles and nanomicelles. Studies in vitro and in vivo have demonstrated that new formulations could help to improve the bioavailability of the drugs, provide sustained drug release, enhance and prolong their therapeutic action. Promising results were obtained with drug-loaded nanoparticles included in in situ gel.

KPI-121 1% for pain and inflammation in ocular surgery

Pain and inflammation are common experiences following ocular surgery and, if uncontrolled, can compromise patients' vision, functioning and quality of life. Corticosteroid drugs are available to manage inflammation and discomfort but have limitations in penetrating the ocular mucus barrier to reach the target ocular tissues. KPI-121 1% (INVELTYS^®) is a novel formulation of loteprednol etabonate that employs innovative proprietary technology to deliver nanoparticle-sized mucus-penetrating particles to the cornea. Results from clinical trials demonstrate that KPI-121 1% is effective and well tolerated. KPI-121 1% uses mucopenetrative technology for ophthalmic use and is the only US FDA-approved twice-daily ocular corticosteroid indicated for the treatment of inflammation and pain after ocular surgery.

The role of KPI-121 0.25% in the treatment of dry eye disease: penetrating the mucus barrier to treat periodic flares

The tear film, which includes mucins that adhere to foreign particles, rapidly clears allergens and pathogens from the ocular surface, protecting the underlying tissues. However, the tear film’s ability to efficiently remove foreign particles during blinking can also pose challenges for topical drug delivery, as traditional eye drops (solutions and suspensions) are cleared from the ocular surface before the drug can penetrate into the conjunctival and corneal epithelium. In the past 15 years, there has been an increase in the development of nanoparticles with specialized coatings that have reduced affinity to mucins and are small enough in size to pass through the mucus barrier. These mucus-penetrating particles (MPPs) have been shown to efficiently penetrate the mucus barrier and reach the ocular surface tissues. Dry eye disease (DED) is a common inflammatory ocular surface disorder that often presents with periodic flares (exacerbations). However, currently approved immunomodulatory treatments for DED are intended for long-term use. Thus, there is a need for effective short-term treatments that can address intermittent flares of DED. Loteprednol etabonate, an ocular corticosteroid, was engineered to break down rapidly after administration to the ocular surface tissues and thereby reduce risks associated with other topical steroids. KPI-121 is an ophthalmic suspension that uses the MPP technology to deliver loteprednol etabonate more efficiently to the ocular tissues, achieving in animal models a 3.6-fold greater penetration of loteprednol etabonate to the cornea than traditional loteprednol etabonate ophthalmic suspensions. In clinical trials, short-term treatment with KPI-121 0.25% significantly reduced signs and symptoms of DED compared with its vehicle (placebo). Recently approved KPI-121 0.25%, with its novel drug delivery design and ease of use, has the potential to effectively treat periodic flares of DED experienced by many patients.

Avoiding a Sticky Situation: Bypassing the Mucus Barrier for Improved Local Drug Delivery

The efficacy of drugs administered by traditional routes is limited by numerous biological barriers that preclude reaching the intended site of action. Further, full body systemic exposure leads to dose-limiting, off-target side effects. Topical formulations may provide more efficacious drug and nucleic acid delivery for diseases and conditions affecting mucosal tissues, but the mucus protecting our epithelial surfaces is a formidable barrier. Here, we describe recent advances in mucus-penetrating approaches for drug and nucleic acid delivery to the ocular surface, the female reproductive tract, the gastrointestinal tract, and the airways.

Current and Future Pharmacological Therapies for the Management of Dry Eye

Dry eye disease (DED) is among the most common reasons for visiting eye care practitioners and represents a substantial health and cost burden. Disease prevalence ranges from 5% to 33% and is increasing in the younger population. The core mechanism of DED involves a vicious cycle where hyperosmolarity leads to an inflammatory cascade resulting in ocular surface damage. No cure is available for DED, and patients require ongoing disease management. Over-the-counter medications can provide temporary symptom relief but do not tackle the inflammatory pathophysiology of DED. A number of medications with anti-inflammatory activity are available, but there is a need for development of pharmacotherapies with novel delivery methods and targets to widen the variety of treatment options. This review discusses current anti-inflammatory pharmacotherapies approved in the United States and Europe for DED and highlights novel drugs that have been recently approved or are in development.

A review of the clinical applications of drug delivery systems for the treatment of ocular anterior segment inflammation

Ocular anterior segment inflammation is a medical problem that is seen in cases of cataract surgery and non-infectious anterior uveitis. Inadequately treated anterior segment inflammation can lead to sight-threatening conditions such as corneal oedema, glaucoma and cystoid macular oedema. The mainstay of treatment for anterior segment inflammation is topical steroid eye-drops. However, several drawbacks limit the critical value of this treatment, including low bioavailability, poor patient compliance, relatively difficult administration manner and risk of blurring of vision and ocular irritation. A drug delivery system (DDS) that can provide increased bioavailability and sustained delivery while being specifically targeted towards inflamed ocular tissue can potentially replace daily eye-drops as the gold standard for management of anterior segment inflammation. The various DDS for anti-inflammatory drugs for the treatment of anterior segment inflammation are listed and summarised in this review, with a focus on commercially available products and those in clinical trials. Dextenza, INVELTYS, Dexycu and Bromsite are examples of DDS that have enjoyed success in clinical trials leading to FDA approval. Nanoparticles and ocular iontophoresis form the next wave of DDS that have the potential to replace topical steroids eye-drops as the treatment of choice for anterior segment inflammation. With the current relentless pace of ophthalmic drug delivery research, the pursuit of a new standard of treatment that eliminates the problems of low bioavailability and patient compliance may soon be realised.

Emerging corticosteroid delivery platforms for treatment of diabetic macular edema

INTRODUCTION

Diabetic macular edema (DME) is a leading cause of vision impairment. Low-grade inflammation is thought to play a critical role in its pathogenesis. Although vascular endothelial growth factor inhibitors are used first-line, not all eyes with DME respond optimally and may respond better to corticosteroids. Currently corticosteroids for DME are given intravitreally and require regular monitoring. There is an unmet need for longer lasting therapies and/or effective noninvasive therapies such as those given via oral or topical routes.

AREAS COVERED

This review discusses emerging corticosteroid delivery platforms for DME treatment. A literature search of investigational novel therapeutic steroid delivery platform in DME was conducted. Results are presented from preclinical, phase 1,2 & 3 clinical trials of various drug delivery systems using new technologies such as Solubilizing Nanoparticle technology, Mucus Penetrating Particles technology and Particle Replication In Non-wetting Templates. These new platforms aim to deliver corticosteroids effectively via topical, episcleral, subtenon, oral, and intravitreal routes.

EXPERT OPINION

These novel drug delivery platforms have the potential to lead to noninvasive or minimally invasive therapies and may overcome the shortcomings of current pharmacotherapy. However, larger comparative trials are needed for these agents to be added to the current armamentarium in DME management.

Mucus-Penetrating Particles and the Role of Ocular Mucus as a Barrier to Micro- and Nanosuspensions

The ocular surface is naturally covered with a layer of mucus. Along with other functions, this mucus layer serves to trap and eliminate foreign substances, such as allergens, pathogens, and debris. In playing this pivotal role, mucus can also hinder topical delivery of therapeutics to the eye. Recent studies provide evidence that drugs formulated as traditional micro- or nanoparticles are susceptible to entrapment and rapid clearance by ocular mucus. Mucus-penetrating particles (MPPs) is a nanoparticle technology that emerged over the past decade. With a muco-inert surface and a particle size smaller than the mucus mesh size, MPPs can diffuse in ex vivo mucus essentially freely. Preclinical studies have shown that, compared with particles lacking the mucus-penetrating attributes, MPPs can improve the uniformity of drug particle distribution on mucosal surfaces and enhance drug delivery to ocular tissues.

Risk of intraocular pressure elevation after topical steroids in children and adults: A systematic review

Topical steroids may induce a rise in intraocular pressure. The risk may increase with prolonged use, high frequency of administration, young age, higher ocular penetrance and higher anti-inflammatory potency. We aimed to study this relationship by comparing published rates of intraocular pressure elevation following administration of topical steroids and compared the risk of higher versus lower dosage regimes, high- versus low-potency/penetration steroids and adults versus children. Data sources used were Ovid Embase, Ovid Medline, the Cochrane Central Register of Controlled Trials, Web of Science, Scopus, CINHAL Plus and LILACS. Eligible studies were randomised controlled trials of topical steroids versus any other topical steroid, nonsteroidal anti-inflammatory drugs, placebo or vehicle, or a different mode of administration administered for 7 days or longer that reported intraocular pressure elevation from baseline as >10, 6-15 or >15 mm Hg in adults or children. Risks of bias were reviewed using the GRADE quality approach. Data were extracted into the software package, RevMan, Version 5 (Cochrane Collaboration). In total, 43 studies were included. Meta-analysis was not possible. Topical steroids of lower anti-inflammatory potency, and with reduced intraocular penetration, are associated with reduced incidence of intraocular pressure elevation. A comparison of data in children and adults is limited by the use of different reporting systems. The principal obstacle to meta-analysis is the different reporting systems used to categorise intraocular pressure elevation. We recommend future studies should report intraocular pressure elevation >10 mm Hg from baseline to allow meta-analysis of data.

Loteprednol etabonate (submicron) ophthalmic gel 0.38% dosed three times daily following cataract surgery: integrated analysis of two Phase III clinical studies

Purpose

To evaluate the efficacy and safety of a submicron formulation of loteprednol etabonate (LE) gel 0.38% instilled three times daily (TID) compared with vehicle for the treatment of inflammation and pain following cataract surgery with intraocular lens implantation, integrated across two multicenter, double-masked, randomized, parallel-group, Phase III studies.

Patients and methods

Subjects ≥18 years of age with anterior chamber (AC) cells ≥grade 2 (6-15 cells) on day 1 after cataract surgery were randomized to receive 1 drop of LE gel 0.38% TID, twice daily (not reported/analyzed herein), or vehicle instilled in the study eye for 14 days. Primary endpoints were the proportion of subjects with resolution of AC cells and grade 0 (no) pain at postoperative day 8. Safety outcomes included adverse events (AEs), ocular signs, fundoscopy results, visual acuity, intraocular pressure (IOP), and tolerability (drop comfort and ocular symptoms).

Results

The integrated intent-to-treat population included 742 subjects (LE gel 0.38% TID, n=371; vehicle, n=371). Significantly more subjects in the LE gel 0.38% TID group compared with the vehicle group had complete resolution of AC cells (29.6% vs 15.1%) and grade 0 pain (74.4% vs 48.8%) at day 8 (P<0.0001 for both). LE gel 0.38% TID was safe and well tolerated, with only 1 LE-treated subject experiencing an IOP elevation ≥10 mm Hg. Most treatment-related AEs were mild and occurred less frequently with LE gel 0.38% than with vehicle. The majority (>75%) of subjects in each treatment group reported no drop discomfort. There were no reports of blurred vision with LE gel.

Conclusion

The results of this integrated analysis indicate that LE (submicron) gel 0.38% administered TID is safe and effective for the treatment of ocular inflammation and pain following cataract surgery, with minimal risk of IOP elevation.