Latanoprostene Bunod Ophthalmic Solution 0.024%: A Review in Open-Angle Glaucoma and Ocular Hypertension

Effect of Bromfenac on Reducing Neuroinflammation in an Ischemia-Reperfusion Glaucoma Model

In the context of glaucoma, intraocular pressure (IOP) and age are recognized as the primary factors contributing to its onset and progression. However, significant reductions in IOP fail to completely halt its advancement. An emerging body of literature highlights the role of neuroinflammation in glaucoma. This study aimed to explore Bromfenac's anti-inflammatory properties in mitigating neuroinflammation associated with glaucoma using an ischemia-reperfusion (IR) glaucoma model. Bromfenac's impact on microglia and astrocytes under pressure was assessed via Western blotting and an enzyme-linked immunosorbent assay. Immunohistochemical staining was used to evaluate glial activation and changes in inflammatory marker expression in the IR model. Bromfenac led to the downregulation of inflammatory markers, which were elevated in the conditions of elevated pressure, and necroptosis markers were downregulated in astrocytes. In the IR model, elevated levels of GFAP and Iba-1 indicated glial activation. Following Bromfenac administration, levels of iNOS, COX-2, and PGE2-R were reduced, suggesting a decrease in neuroinflammation. Furthermore, Bromfenac administration in the IR model resulted in the improved survival of retinal ganglion cells (RGCs) and preservation of retinal function, as demonstrated by immunohistochemical staining and electroretinography. In summary, Bromfenac proved effective in diminishing neuroinflammation and resulted in enhanced RGC survival.

Prodrugs as empowering tools in drug discovery and development: recent strategic applications of drug delivery solutions to mitigate challenges associated with lead compounds and drug candidates

The delivery of a drug to a specific organ or tissue at an efficacious concentration is the pharmacokinetic (PK) hallmark of promoting effective pharmacological action at a target site with an acceptable safety profile. Sub-optimal pharmaceutical or ADME profiles of drug candidates, which can often be a function of inherently poor physicochemical properties, pose significant challenges to drug discovery and development teams and may contribute to high compound attrition rates. Medicinal chemists have exploited prodrugs as an informed strategy to productively enhance the profiles of new chemical entities by optimizing the physicochemical, biopharmaceutical, and pharmacokinetic properties as well as selectively delivering a molecule to the site of action as a means of addressing a range of limitations. While discovery scientists have traditionally employed prodrugs to improve solubility and membrane permeability, the growing sophistication of prodrug technologies has enabled a significant expansion of their scope and applications as an empowering tool to mitigate a broad range of drug delivery challenges. Prodrugs have emerged as successful solutions to resolve non-linear exposure, inadequate exposure to support toxicological studies, pH-dependent absorption, high pill burden, formulation challenges, lack of feasibility of developing solid and liquid dosage forms, first-pass metabolism, high dosing frequency translating to reduced patient compliance and poor site-specific drug delivery. During the period 2012-2022, the US Food and Drug Administration (FDA) approved 50 prodrugs, which amounts to 13% of approved small molecule drugs, reflecting both the importance and success of implementing prodrug approaches in the pursuit of developing safe and effective drugs to address unmet medical needs.

Chemical Insights into Topical Agents in Intraocular Pressure Management: From Glaucoma Etiopathology to Therapeutic Approaches

Glaucoma encompasses a group of optic neuropathies characterized by complex and often elusive etiopathology, involvihttng neurodegeneration of the optic nerve in conjunction with abnormal intraocular pressure (IOP). Currently, there is no cure for glaucoma, and treatment strategies primarily aim to halt disease progression by managing IOP. This review delves into the etiopathology, diagnostic methods, and treatment approaches for glaucoma, with a special focus on IOP management. We discuss a range of active pharmaceutical ingredients used in glaucoma therapy, emphasizing their chemical structure, pharmacological action, therapeutic effectiveness, and safety/tolerability profiles. Notably, most of these therapeutic agents are administered as topical formulations, a critical aspect considering patient compliance and drug delivery efficiency. The classes of glaucoma therapeutics covered in this review include prostaglandin analogs, beta blockers, alpha agonists, carbonic anhydrase inhibitors, Rho kinase inhibitors, and miotic (cholinergic) agents. This comprehensive overview highlights the importance of topical administration in glaucoma treatment, offering insights into the current state and future directions of pharmacological management in glaucoma.

Therapeutic strategies for glaucoma and optic neuropathies

Glaucoma is a neurodegenerative eye disease that causes permanent vision impairment. The main pathological characteristics of glaucoma are retinal ganglion cell (RGC) loss and optic nerve degeneration. Glaucoma can be caused by elevated intraocular pressure (IOP), although some cases are congenital or occur in patients with normal IOP. Current glaucoma treatments rely on medicine and surgery to lower IOP, which only delays disease progression. First-line glaucoma medicines are supported by pharmacotherapy advancements such as Rho kinase inhibitors and innovative drug delivery systems. Glaucoma surgery has shifted to safer minimally invasive (or microinvasive) glaucoma surgery, but further trials are needed to validate long-term efficacy. Further, growing evidence shows that adeno-associated virus gene transduction and stem cell-based RGC replacement therapy hold potential to treat optic nerve fiber degeneration and glaucoma. However, better understanding of the regulatory mechanisms of RGC development is needed to provide insight into RGC differentiation from stem cells and help choose target genes for viral therapy. In this review, we overview current progress in RGC development research, optic nerve fiber regeneration, and human stem cell-derived RGC differentiation and transplantation. We also provide an outlook on perspectives and challenges in the field.

Therapeutic Potential of Antioxidants and Hybrid TEMPOL Derivatives in Ocular Neurodegenerative Diseases: A Glimpse into the Future

Reactive oxygen species play a significant role in the pathogenesis of various ocular neurodegenerative diseases especially glaucoma, age-related macular degeneration (AMD), and ocular ischemic stroke. Increased oxidative stress and the accumulation of ROS have been implicated in the progression of these diseases. As a result, there has been growing interest in exploring potential therapeutic and prophylactic strategies involving exogenous antioxidants. In recent years, there have been significant advancements in the development of synthetic therapeutic antioxidants for targeting reactive oxygen species (ROS) in neurodegenerative diseases. One area of focus has been the development of hybrid TEMPOL derivatives. In the context of ocular diseases, the application of next-generation hybrid TEMPOL antioxidants may offer new avenues for neuroprotection. By targeting ROS and reducing oxidative stress in the retina and optic nerve, these compounds have the potential to preserve retinal ganglion cells and trabecular meshwork and protect against optic nerve damage, mitigating irreversible blindness associated with these diseases. This review seeks to highlight the potential impact of hybrid TEMPOL antioxidants and their derivatives on ocular neurodegenerative disorders.

Nitric oxide: an old drug but with new horizons in ophthalmology-a narrative review

Background and Objective

Based on basic knowledge and prior research on nitric oxide (NO), the potential of NO for treating eye diseases is reviewed, and the possibility of NO-based eye drops in clinical practice and the future potential of NO in ophthalmology are discussed.

Methods

A PubMed search was performed for English-language original reports and reviews using the following key words: nitric oxide, eye, ocular, and drug.

Key Content and Findings

NO is synthesized in the human body by NO synthase (NOS) from L-arginine or through enzyme-dependent reduction of dietary nitrate. Three types of NOS (eNOS, nNOS, and iNOS) are abundantly expressed in the eye under normal physiologic or pathologic conditions. The biological effect of NO in the eye is dose dependent. Low intraocular NO concentrations, produced by eNOS or nNOS, have various cellular effects, including vasodilation, intraocular pressure (IOP) regulation, and neuroprotection. iNOS induced under pathologic ocular conditions produces high NO concentrations in the local environment and mediates tissue inflammation, ocular cell apoptosis, and neurodegeneration. In particular, increased iNOS has been reported in glaucoma and retinal ischemic or degenerative diseases. NO plays a vital role in ocular injury. NO can facilitate ocular surface wound healing while eradicating pathogens such as bacteria and Acanthamoeba in chemical burns or infectious keratitis. Furthermore, NO has antifibrotic activity via the cyclic guanosine monophosphate (cGMP) signaling pathway. NO causes smooth muscle relaxation, which can be used to inhibit myopia progression in children. NO can be a stem cell modulator and may help in treating ocular stem cell disorders.

Conclusions

Because of its diverse biologic effects, NO can be a key player in regulating ocular inflammation in various ocular diseases, aiding ocular surface wound healing, controlling IOP in glaucoma, alleviating retinal disease, and suppressing myopia progression. Although there remain limitations to the effective use of highly unstable state, gaseous NO, the role of NO in the field of ophthalmology can be greatly expanded through the development of novel NO donors and effective delivery platforms.

Recently Approved Drugs for Lowering and Controlling Intraocular Pressure to Reduce Vision Loss in Ocular Hypertensive and Glaucoma Patients

Serious vision loss occurs in patients affected by chronically raised intraocular pressure (IOP), a characteristic of many forms of glaucoma where damage to the optic nerve components causes progressive degeneration of retinal and brain neurons involved in visual perception. While many risk factors abound and have been validated for this glaucomatous optic neuropathy (GON), the major one is ocular hypertension (OHT), which results from the accumulation of excess aqueous humor (AQH) fluid in the anterior chamber of the eye. Millions around the world suffer from this asymptomatic and progressive degenerative eye disease. Since clinical evidence has revealed a strong correlation between the reduction in elevated IOP/OHT and GON progression, many drugs, devices, and surgical techniques have been developed to lower and control IOP. The constant quest for new pharmaceuticals and other modalities with superior therapeutic indices has recently yielded health authority-approved novel drugs with unique pharmacological signatures and mechanism(s) of action and AQH drainage microdevices for effectively and durably treating OHT. A unique nitric oxide-donating conjugate of latanoprost, an FP-receptor prostaglandin (PG; latanoprostene bunod), new rho kinase inhibitors (ripasudil; netarsudil), a novel non-PG EP2-receptor-selective agonist (omidenepag isopropyl), and a form of FP-receptor PG in a slow-release intracameral implant (Durysta) represent the additions to the pharmaceutical toolchest to mitigate the ravages of OHT. Despite these advances, early diagnosis of OHT and glaucoma still lags behind and would benefit from further concerted effort and attention.

FP and EP2 prostanoid receptor agonist drugs and aqueous humor outflow devices for treating ocular hypertension and glaucoma

Prostaglandin (PG) receptors represent important druggable targets due to the many diverse actions of PGs in the body. From an ocular perspective, the discovery, development, and health agency approvals of prostaglandin F (FP) receptor agonists (FPAs) have revolutionized the medical treatment of ocular hypertension (OHT) and glaucoma. FPAs, such as latanoprost, travoprost, bimatoprost, and tafluprost, powerfully lower and control intraocular pressure (IOP), and became first-line therapeutics to treat this leading cause of blindness in the late 1990s to early 2000s. More recently, a latanoprost-nitric oxide (NO) donor conjugate, latanoprostene bunod, and a novel FP/EP3 receptor dual agonist, sepetaprost (ONO-9054 or DE-126), have also demonstrated robust IOP-reducing activity. Moreover, a selective non-PG prostanoid EP2 receptor agonist, omidenepag isopropyl (OMDI), was discovered, characterized, and has been approved in the United States, Japan and several other Asian countries for treating OHT/glaucoma. FPAs primarily enhance uveoscleral (UVSC) outflow of aqueous humor (AQH) to reduce IOP, but cause darkening of the iris and periorbital skin, uneven thickening and elongation of eyelashes, and deepening of the upper eyelid sulcus during chronic treatment. In contrast, OMDI lowers and controls IOP by activation of both the UVSC and trabecular meshwork outflow pathways, and it has a lower propensity to induce the aforementioned FPA-induced ocular side effects. Another means to address OHT is to physically promote the drainage of the AQH from the anterior chamber of the eye of patients with OHT/glaucoma. This has successfully been achieved by the recent approval and introduction of miniature devices into the anterior chamber by minimally invasive glaucoma surgeries. This review covers the three major aspects mentioned above to highlight the etiology of OHT/glaucoma, and the pharmacotherapeutics and devices that can be used to combat this blinding ocular disease.

Selective laser trabeculoplasty is safe and effective in patients previously treated with prostaglandin analogs: An evidence-based review

PURPOSE

Prostaglandin analogs (PGAs) are first-line treatments for ocular hypertension (OHT) and open-angle glaucoma (OAG). However, frequent side effects and high costs hinder patient's compliance resulting in disease progression. Evidence suggests selective laser trabeculoplasty (SLT) may be considered a first-line treatment for OHT and OAG due to its safety profile, minor side effects, and reduced costs. Considering that PGAs and SLT share action mechanisms, it is hypothesized that previous PGA therapy may affect subsequent SLT efficacy. Therefore, we analyzed if PGAs reduce SLT efficacy.

METHODS

An evidence-based review was performed to assess the safety and efficacy of SLT in patients previously treated with PGAs. For this purpose, we performed an extensive literature search using the National Library of Medicine's PubMed and Google Scholar database for all English language articles published until May 2021.

RESULTS

There is evidence of non-superiority of PGAs therapy versus SLT for OHT and OAG. A multicenter, randomized, observer-masked clinical trial (RCT) of untreated OHT and OAG patients concluded that SLT should be offered as the first-line treatment for these patients. This study was supported by a meta-analysis of RCTs, comparing SLT efficacy versus antiglaucoma drugs only, with the advantage of an SLT lower rate of adverse effects.

CONCLUSIONS

Cost-effectiveness, patient compliance, and antiglaucoma drugs' side effects, including higher surgical failure, favor consideration of SLT as first-line therapy for OAG and OHT. Furthermore, SLT efficacy does not seem to be affected by prior PGA administration; however, larger cohort, comparative, multicenter RCTs are necessary to answer this question.

Trends in development and quality assessment of pharmaceutical formulations - F2α analogues in the glaucoma treatment

The ocular delivery route presents a number of challenges in terms of drug administration and bioavailability. The low bioavailability following topical ophthalmic administration shows that there is a clear need for in-depth research aimed at finding both more efficacious molecules and formulations precisely targeted at the site of action. Continuous technological development will eventually result in improved bioavailability, lower dosages, reduced toxicity, fewer adverse effects, and thus better patient compliance and treatment efficacy. Technological development, as well as increasingly stringent quality requirements, help stimulate analytical progress. This is also clearly evident in the case of medicinal products used in the treatment of glaucoma, which are the subject of this review. Impurity profiling of PGF2α analogues, either in the pure substance or in the finished formulation, is a crucial step in assessing their quality. The development of specific, accurate and precise stability-indicating analytical methods for determining the content and related substances seems to be an important issue in relation to this tasks. A total of 27 official and in-house analytical methods are presented that are used for the analysis of latanoprost, travoprost and bimatoprost. The conditions for chromatographic separation with UV or MS/MS detection and the available results obtained during method validation are described. In addition, several aspects are discussed, with particular emphasis on the instability of the analogues in aqueous solution and the phenomenon of isomerism, which affects a potentially large number of degradation products.

Newer advances in medical management of glaucoma

The burden of irreversible vision loss from Glaucoma continues to rise. While the disease pathogenesis is not well understood, intraocular pressure (IOP) is the only modifiable risk factor identified to prevent glaucomatous vision loss. Medical management remains the first-line of treatment in most adult glaucomas and the evolution of medical therapy for glaucoma has followed an exponential curve. This review tracks the rapid development of new medications and drug delivery systems in the recent years. Introduction of Rho kinase inhibitors with an entirely new mechanism of action from that of the currently used anti glaucoma medications has been a significant milestone. Latanoprostene Bunod is a novel, single molecule which provides two active metabolites that work through two different pathways for reducing intra ocular pressure. Bimatoprost implants and travoprost punctum plugs attempt to ease chronic medication use in glaucoma patients. Nanotechnology is an evolving route of drug delivery. Role of cannabinoids in medical management of glaucoma remain equivocal. The relatively short term effect on IOP, the risks of developing tolerance and side effects impacting patients' neurocognitive health greatly outweigh the potential benefit. Research on Latrunculin B, Adenosine receptor agonists, Specific gene silencing and Stem cell therapy are poised to make an impact on glaucoma treatment. While there is some evidence to support the role of Brimonidine in neuroprotection, further research is needed to clarify the role of Memantine and Neurotrophins. Evidence for benefit from dietary supplementation with Alpha lipoic acid, Forskolin , and Ginko Biloba is limited.

Glucocorticoids Preferentially Influence Expression of Nucleoskeletal Actin Network and Cell Adhesive Proteins in Human Trabecular Meshwork Cells

Clinical use of glucocorticoids is associated with increased intraocular pressure (IOP), a major risk factor for glaucoma. Glucocorticoids have been reported to induce changes in actin cytoskeletal organization, cell adhesion, extracellular matrix, fibrogenic activity, and mechanical properties of trabecular meshwork (TM) tissue, which plays a crucial role in aqueous humor dynamics and IOP homeostasis. However, we have a limited understanding of the molecular underpinnings regulating these myriad processes in TM cells. To understand how proteins, including cytoskeletal and cell adhesion proteins that are recognized to shuttle between the cytosolic and nuclear regions, influence gene expression and other cellular activities, we used proteomic analysis to characterize the nuclear protein fraction of dexamethasone (Dex) treated human TM cells. Treatment of human TM cells with Dex for 1, 5, or 7 days led to consistent increases (by ≥ two-fold) in the levels of various actin cytoskeletal regulatory, cell adhesive, and vesicle trafficking proteins. Increases (≥two-fold) were also observed in levels of Wnt signaling regulator (glypican-4), actin-binding chromatin modulator (BRG1) and nuclear actin filament depolymerizing protein (MICAL2; microtubule-associated monooxygenase, calponin and LIM domain containing), together with a decrease in tissue plasminogen activator. These changes were independently further confirmed by immunoblotting analysis. Interestingly, deficiency of BRG1 expression blunted the Dex-induced increases in the levels of some of these proteins in TM cells. In summary, these findings indicate that the widely recognized changes in actin cytoskeletal and cell adhesive attributes of TM cells by glucocorticoids involve actin regulated BRG1 chromatin remodeling, nuclear MICAL2, and glypican-4 regulated Wnt signaling upstream of the serum response factor/myocardin controlled transcriptional activity.

Medical therapy for glaucoma: A review

A number of pharmacological targets are exploited to modify the parameters in the Goldmann equation and reduce the intraocular pressure (IOP). This strategy constitutes the foundation for the medical management of glaucoma, the evolution of which, until only recently, has been in relative stagnation. A burst of innovation has produced new ocular hypotensive drugs and long-acting delivery methods, including intracameral delivery, which are expanding the clinician's medical armamentarium. A number of IOP-independent neuroprotection strategies have shown strong potential in animal models of glaucoma, but translational attempts have been surprisingly limited. However, while pharmacological options are expanding, the traditional role of topical medical therapy is being challenged by selective laser trabeculoplasty, micro-invasive glaucoma surgery, and sustained delivery methods. A scientifically rigorous assessment of new treatments will be critical to empower clinicians with evidence-based information to optimise vision preservation and quality of life outcomes for their patients.

Topical Medication Therapy for Glaucoma and Ocular Hypertension

Glaucoma is one of the most common causes of blindness, thus seriously affecting people’s health and quality of life. The topical medical therapy is as the first line treatment in the management of glaucoma since it is inexpensive, convenient, effective, and safe. This review summarizes and compares extensive clinical trials on the topical medications for the treatment of glaucoma, including topical monotherapy agents, topical fixed-combination agents, topical non-fixed combination agents, and their composition, mechanism of action, efficacy, and adverse effects, which will provide reference for optimal choice of clinical medication. Fixed-combination therapeutics offer greater efficacy, reliable security, clinical compliance, and tolerance than non-fixed combination agents and monotherapy agents, which will become a prefer option for the treatment of glaucoma. Meanwhile, we also discuss new trends in the field of new fixed combinations of medications, which may better control IOP and treat glaucoma.

Minimally Invasive Glaucoma Surgery-to Remove or Preserve the Trabecular Meshwork: That is the Question?

How to cite this article: Dada T, Mahalingam K, Bhartiya S. Minimally Invasive Glaucoma Surgery—to Remove or Preserve the Trabecular Meshwork: That is the Question? J Curr Glaucoma Pract 2021;15(2):47–51.

Drugs for the treatment of glaucoma: Targets, structure-activity relationships and clinical research

Glaucoma is the third leading cause of blindness and impairment of vision worldwide, after refractive errors and cataracts. According to the survey, the number of people with glaucoma is more than 76 million, with projections increasing to 112 million by 2040. With the coming of an aging society, the number of people suffering from glaucoma will increase day by day. Glaucoma is a heterogeneous disease characterized by damage to the head of the optic nerve and visual field. High intraocular pressure is a major risk and cause of glaucoma optic neuropathy. Therefore, drug lowering intraocular pressure therapy is still the first-line therapy in clinical practice. Here, the targets, structure-activity relationship, and clinical progress of drugs for the treatment of glaucoma are reviewed.

Two-Year Experience With Latanoprostene Bunod in Clinical Practice

PRECIS

We retrospectively reviewed records of patients prescribed latanoprostene bunod 0.024% (LBN) to assess its efficacy and safety in a real-world clinical setting. LBN was efficacious in lowering intraocular pressure (IOP) and had a favorable safety profile.

PURPOSE

The aim of this study was to evaluate the usage of LBN, the first topical nitric oxide-donating prostaglandin analog (PGA) for reducing IOP, in clinical practice.

PATIENTS AND METHODS

Retrospective review identified patients prescribed LBN by 5 glaucoma specialists at an academic center from January 2018 to November 2019. Fifty-six patients (102 eyes) met inclusion criteria of an IOP measured at the visit LBN was prescribed and at 2 visits ≥7 days after beginning treatment, with no surgeries, lasers or medication changes during follow-up. Main outcome measures were IOP, number of ocular medications, and adverse effects.

RESULTS

IOP (mean±SD, mm Hg) at the visit LBN was prescribed was 16.2±4.3 on 3.2±1.5 glaucoma medications. IOP at most recent visit was 13.7±3.8 on 3.2±1.6 medications. Mean IOP reduction was 2.1±3.5 (P<0.0001) at first follow-up, after 38.7±36.5 days, and 2.5±3.3 (P<0.0001) at last follow-up, after 235.9±160.8 days. Pressure decreased ≥2 mm Hg in 60%, ≥3 mm Hg in 46%, and ≥4 mm Hg in 34% of eyes. All patients received LBN as replacement for a PGA or latanoprost/netarsudil fixed-dose combination. Forty-three patients remained on LBN throughout the follow-up period. Seven were discontinued for insufficient pressure control, 4 for adverse effects including pain and itching, and 2 for financial reasons.

CONCLUSIONS

In 2 years of clinical use of LBN, patients exhibited IOP reductions that were statistically significant overall and clinically meaningful in 60% of patients. LBN was well-tolerated and may be more efficacious than traditional PGAs.

Recent advances on endogenous gasotransmitters in inflammatory dermatological disorders

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Endogenous gasotransmitters nitric oxide (NO), carbon monoxide (CO), hydrogen sulfide (H₂S), and potential candidates sulfur dioxide (SO₂), methane (CH₄), hydrogen gas (H₂), ammonia (NH₃) and carbon dioxide (CO₂), are generated within the human body.

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Endogenous and potential gasotransmitters regulate inflammation, vasodilation, and oxidation in inflammatory dermatological disorders.

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Endogenous and potential gasotransmitters play potential roles in psoriasis, atopic dermatitis, acne, and chronic skin ulcers.

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Further research should explore the function of these gases and gas donors and inhibitors in inflammatory dermatological disorders.

Background

Endogenous gasotransmitters are small gaseous mediators that can be generated endogenously by mammalian organisms. The dysregulation of the gasotransmitter system is associated with numerous disorders ranging from inflammatory diseases to cancers. However, the relevance of these endogenous gasotransmitters, prodrug donors and inhibitors in inflammatory dermatological disorders has not yet been thoroughly reviewed and discussed.

Aim of review

This review discusses the recent progress and will provide perspectives on endogenous gasotransmitters in the context of inflammatory dermatological disorders.

Key scientific concepts of review

Endogenous gasotransmitters nitric oxide (NO), carbon monoxide (CO) and hydrogen sulfide (H₂S) are signaling molecules that regulate several physiological and pathological processes. In addition, sulfur dioxide (SO₂), methane (CH₄), hydrogen gas (H₂), ammonia (NH₃), and carbon dioxide (CO₂) can also be generated endogenously and may take part in physiological and pathological processes. These signaling molecules regulate inflammation, vasodilation, and oxidative stress, offering therapeutic potential and attracting interest in the field of inflammatory dermatological disorders including psoriasis, atopic dermatitis, acne, rosacea, and chronic skin ulcers. The development of effective gas donors and inhibitors is a promising alternative to treat inflammatory dermatological disorders with controllable and precise delivery in the future.

Myocilin-associated Glaucoma: A Historical Perspective and Recent Research Progress

Glaucoma a debilitating disease, is globally the second most common kind of permanent blindness. Primary open-angle glaucoma (POAG) is its most prevalent form and is often linked with alterations in the myocilin gene (MYOC). MYOC encodes the myocilin protein, which is expressed throughout the body, but primarily in trabecular meshwork (TM) tissue in the eyes. TM is principally involved in regulating intraocular pressure (IOP), and elevated IOP is the main risk factor associated with glaucoma. The myocilin protein's function remains unknown; however, mutations compromise its folding and processing inside TM cells, contributing to the glaucoma phenotype. While glaucoma is a complex disease with various molecules and factors as contributing causes, the role played by myocilin has been the most widely studied. The current review describes the present understanding of myocilin and its association with glaucoma and aims to shift the focus toward developing targeted therapies for treating glaucoma patients with variations in MYOC.

Xeno- and Feeder-Free Differentiation of Human iPSCs to Trabecular Meshwork-Like Cells by Recombinant Cytokines

Purpose

Stem cell-based therapy has the potential to become one approach to regenerate the damaged trabecular meshwork (TM) in glaucoma. Co-culture of induced pluripotent stem cells (iPSCs) with human TM cells has been a successful approach to generate autologous TM resembling cells. However, the differentiated cells generated using this approach are still problematic for clinical usage. This study aimed to develop a clinically applicable strategy for generating TM-like cells from iPSCs.

Methods

Highly expressed receptors during iPSC differentiation were identified by AutoSOME, Gene Ontology, and reverse transcription polymerase chain reaction (RT-PCR) analysis. The recombinant cytokines that bind to these receptors were used to generate a new differentiation protocol. The resultant TM-like cells were characterized morphologically, immunohistochemically, and transcriptionally.

Results

We first determined two stages of iPSC differentiation and identified highly expressed receptors associated with the differentiation at each stage. The expression of these receptors was further confirmed by RT-PCR analysis. Exposure to the recombinant cytokines that bind to these receptors, including transforming growth factor beta 1, nerve growth factor beta, erythropoietin, prostaglandin F2 alpha, and epidermal growth factor, can efficiently differentiate iPSCs into TM-like cells, which express TM biomarkers and can form dexamethasone-inducible CLANs.

Conclusions

We successfully generated a xeno- and feeder-free differentiation protocol with recombinant cytokines to generate the TM progenitor and TM-like cells from human iPSCs.

Translational Relevance

The new approach minimizes the risks from contamination and also improves the differentiation efficiency and consistency, which are particularly crucial for clinical use of stem cells in glaucoma treatment.

Recent advances in prodrug-based nanoparticle therapeutics

Extensive research into prodrug modification of active pharmaceutical ingredients and nanoparticle drug delivery systems has led to unprecedented levels of control over the pharmacological properties of drugs and resulted in the approval of many prodrug or nanoparticle-based therapies. In recent years, the combination of these two strategies into prodrug-based nanoparticle drug delivery systems (PNDDS) has been explored as a way to further advance nanomedicine and identify novel therapies for difficult-to-treat indications. Many of the PNDDS currently in the clinical development pipeline are expected to enter the market in the coming years, making the rapidly evolving field of PNDDS highly relevant to pharmaceutical scientists. This review paper is intended to introduce PNDDS to the novice reader while also updating those working in the field with a comprehensive summary of recent efforts. To that end, first, an overview of FDA-approved prodrugs is provided to familiarize the reader with their advantages over traditional small molecule drugs and to describe the chemistries that can be used to create them. Because this article is part of a themed issue on nanoparticles, only a brief introduction to nanoparticle-based drug delivery systems is provided summarizing their successful application and unfulfilled opportunities. Finally, the review's centerpiece is a detailed discussion of rationally designed PNDDS formulations in development that successfully leverage the strengths of prodrug and nanoparticle approaches to yield highly effective therapeutic options for the treatment of many diseases.

Experience with netarsudil 0.02% and latanoprostene bunod 0.024% as adjunctive therapy for glaucoma

PURPOSE

To assess the effectiveness and safety of adjunctive topical netarsudil 0.02% and latanoprostene bunod 0.024% in patients with glaucoma.

METHODS

A retrospective, multi-center, cohort study of patients with glaucoma treated with netarsudil 0.02% or latanoprostene bunod from five tertiary care centers. Inclusion criteria included patients with glaucoma treated with either medication as adjunctive therapy. Outcomes included mean absolute intraocular pressure (IOP) reduction and relative IOP reduction from baseline. Adverse reactions and reasons for discontinuation were reported. One-way analysis of variance, Kruskal-Wallis rank sum test, and Mann Whitney U test compared the outcomes.

RESULTS

A total of 95 eyes (95 patients) on netarsudil and 41 eyes (41 patients) on latanoprostene bunod were analyzed. Mean duration of use was 54.3 ± 28 days for netarsudil and 82.9 ± 51.2 days for latanoprostene bunod. At the final visit, mean IOP reduction was 3.9 ± 4.6 mmHg (17.5 ± 6.0%) (p < 0.0001) with netarsudil and 2.9 ± 3.7 mmHg (13.6 ± 16.3%) (p < 0.0001) with latanoprostene bunod. IOP lowering did not depend on baseline number of IOP-lowering medications. The most common reason for discontinuation was non-effectiveness in both groups.

CONCLUSION

Similar to monotherapy, netarsudil and latanoprostene bunod demonstrated efficacy in lowering IOP when used as adjunctive therapy.

U.S. FDA Approved Drugs from 2015-June 2020: A Perspective

In the present work, we report compilation and analysis of 245 drugs, including small and macromolecules approved by the U.S. FDA from 2015 until June 2020. Nearly 29% of the drugs were approved for the treatment of various types of cancers. Other major therapeutic areas of focus were infectious diseases (14%); neurological conditions (12%); and genetic, metabolic, and cardiovascular disorders (7-8% each). Itemization of the approved drugs according to the year of approval, sponsor, target, chemical class, major drug-metabolizing enzyme(s), route of administration/elimination, and drug-drug interaction liability (perpetrator or/and victim) is presented and discussed. An effort has been made to analyze the pharmacophores to identify the structural (e.g., aromatic, heterocycle, and aliphatic), elemental (e.g., boron, sulfur, fluorine, phosphorus, and deuterium), and functional group (e.g., nitro drugs) diversity among the approved drugs. Further, descriptor-based chemical space analysis of FDA approved drugs and several strategies utilized for optimizing metabolism leading to their discoveries have been emphasized. Finally, an analysis of drug-likeness for the approved drugs is presented.

Management of glaucoma in pregnancy - balancing safety with efficacy

Glaucoma and pregnancy is an uncommon combination, but it constitutes a very challenging situation for the treating doctor. The challenge is not only controlling the intraocular pressure and preventing glaucoma progression in the mother, but also having to deal with her mental stress and anxiety regarding the safety of her child. The situation is further worsened by the lack of definite guidelines as to how to deal with such patients. Relative rarity of glaucoma in this population restricts any large prospective randomized clinical trials or any large systematic studies. Moreover, none of the existing anti-glaucoma medications is absolutely safe in pregnancy. Current practice patterns depend on some case reports, a few observational studies and a few animal studies that attempt at determining the safety and efficacy of the available medicines. These are then prescribed on the basis of their relative safety in any particular stage of pregnancy or lactation. Newer medications that were released recently in 2018, such as Vyzulta and Rhopressa, presently have limited data to support their safety for use during pregnancy. Laser trabeculoplasty, conventional filtration surgery (of course without anti-metabolites), and minimally invasive glaucoma surgery represent a few non-pharmacological management options. Surgical procedures such as trabeculectomy and tube-shunts or collagen matrix implants, and newer minimally invasive glaucoma surgery procedures such as the gelatin stents are currently being explored and may prove to be viable solutions for severe glaucoma during pregnancy, although they too have their own inherent drawbacks. Management of glaucoma during pregnancy and lactation requires careful consideration of the disease status, gestational stage, US Food and Drug Administration classification and guidelines, and potential benefits and limitations of the various therapeutic modalities. This review focuses on the importance of a multidisciplinary team approach, starting with preconception planning and counseling, determining the treatment options depending on the stage of glaucoma and of pregnancy, and emphasizes the involvement of the patients, their obstetrician, and pediatrician through active discussion regarding the various medical, laser, or surgical modalities currently available or under exploration for use during pregnancy and lactation. The ultimate aim is to achieve an optimal balance between the risks and benefits of any type of intervention, and to customize treatment on an individual basis in order to achieve the best outcomes for both mother and fetus.

Prolonged use of nitric oxide donor sodium nitroprusside induces ocular hypertension in mice

Nitric oxide (NO) donors are promising therapeutic candidates for treating intraocular hypertension (IOP) and glaucoma. This study aims to investigate the effect of prolonged use of NO donor sodium nitroprusside (SNP) on IOP. Since SNP has a short biological half-life, a nanoparticle drug delivery system (mesoporous silica nanoparticles) has been used to deliver SNP to the target tissues (trabecular meshwork and Schlemm's canal). We find that the sustained use of NO donor initially reduced IOP followed, surprisingly, by IOP elevation, which could not recover by drug withdraw but could be reversed by the antioxidant MnTMPyP application. The IOP elevation and normalization coincide with increased and reduced protein nitration in the mouse conventional outflow tissue. These findings suggest that the prolonged use of NO donor SNP may be problematic as it can cause outflow tissue damage by protein nitration. MnTMPyP is protective of the nitrative damage which could be considered to be co-applied with NO donors.

Retrospective Chart Review on Real-World Use of Latanoprostene Bunod 0.024% in Treatment-Naïve Patients with Open-Angle Glaucoma

Introduction

The objective of this study was to evaluate real-world effectiveness of latanoprostene bunod (LBN) ophthalmic solution 0.024% in treatment-naïve patients newly diagnosed with open-angle glaucoma (OAG) or ocular hypertension.

Methods

This multicenter retrospective chart review included patients aged ≥ 18 years, with no history of medical, laser, or surgical intraocular pressure (IOP)-lowering intervention and at least two follow-up visits (spanning ≥ 2 months) following initiation of LBN treatment. Extracted data included age, sex, race, cup-to-disk ratio, central corneal thickness, IOP, visual acuity (VA), concomitant medications, and adverse events. In patients treated bilaterally, the eye with the higher baseline IOP was the study eye.

Results

Medical charts for 65 patients (mean [SD] age, 59 [14] years; 53.8% female) encompassing 125 eyes treated with LBN were reviewed across nine clinical sites. Mean (SD) IOP at baseline was 21.7 (5.9) mmHg. Mean days to first and second follow-up visit were 43 and 141, respectively. LBN use resulted in a mean (SD) reduction from baseline of 7.1 (4.7) and 7.3 (5.1) mmHg at the first and second follow-up visits, respectively (P < 0.0001 for both). Reductions among patients with IOP > 21 mmHg (n = 30) at baseline were 10.0 (4.5) and 11.1 (4.6) mmHg at the first and second follow-up visits (P < 0.0001 for both). There were no meaningful changes in VA. Adverse events appeared infrequent, with only one report of ocular redness.

Conclusion

In this real-world, retrospective chart review, LBN 0.024% use resulted in robust IOP lowering in newly diagnosed OAG patients new to treatment, and appeared well tolerated.

Current and new pharmacotherapeutic approaches for glaucoma

INTRODUCTION

Glaucoma is the leading cause of irreversible blindness worldwide. Medical therapy is the main line of treatment of open-angle glaucoma (OAG) and ocular hypertension. Despite the expansion of the glaucoma lineup with the newly approved medication classes, many barriers and issues still exist with topical therapy. Novel non-topical drug delivery may address such issues, adding more options to glaucoma pharmacotherapy.

AREAS COVERED

This review outlines current topical therapies for glaucoma, in addition to new medications under trials. The issues with topical therapy, in general, are discussed, as well as the new non-topical drug delivery systems. The authors performed a comprehensive search for published studies on glaucoma medical therapy using the electronic database of PubMed and manual search for each medication and non-topical delivery options. The extra- and intraocular delivery methods and the new topical glaucoma medications under research are covered.

EXPERT OPINION

Medical management of glaucoma represents a challenge for both patients and clinicians. Noncompliance (e.g. difficulty with administering the eye drops), cost, side effects, and intraocular pressure fluctuation are the major problems with topical therapy. To overcome such barriers, research should continue in developing new medications and innovation of non-topical drug delivery systems.

Prostaglandin Total Synthesis Enabled by the Organocatalytic Dimerization of Succinaldehyde

Prostaglandins have been attractive targets in total synthesis for over 50 years, resulting in the development of new synthetic strategies and methodologies that have served the broader chemical community. However, these molecules are not just of academic interest, a number of prostaglandin analogues are used in the clinic, and some are even on the WHO list of essential medicines. In this personal account, we describe our own approach to the family of prostaglandins, which centers around the synthesis of a key enal intermediate, formed from the l-proline catalysed dimerization of succinaldehyde. We highlight the discovery and further optimization of this key reaction, its scale up, and subsequent application to a range of prostaglandins.

Management of Glaucoma in Pregnancy

Management of glaucoma during pregnancy represents a challenge for the physician. Important disease and patients' health decisions begin even before conception and continue throughout pregnancy and breastfeeding. The data on this topic is limited due to ethical and legal constraints and challenges of conducting large, prospective, and randomized clinical trials on this patient population. Our review suggests that individually, intraocular pressure is lower in a pregnant woman when compared with a nonpregnant woman. Importantly, the medical management of glaucoma during pregnancy poses special challenges due to the possibility of adverse effects of medications on the fetus and newborn. Laser trabeculoplasty and traditional filtration surgery, and minimally invasive glaucoma surgery, represent nondrug management options. Thus, managing glaucoma in pregnancy is a delicate balance between treatment to prevent damage to the optic nerve in the mother and avoidance of interventions potentially harmful to the fetus. This literature review of published individual and population-based studies was performed to explore current knowledge and guidelines in the management of glaucoma in pregnancy.

Newly Developed Prodrugs and Prodrugs in Development; an Insight of the Recent Years

BACKGROUND

The design and development of prodrugs is the most common and effective strategy to overcome pharmacokinetic and pharmacodynamic drawbacks of active drugs. A respected number of prodrugs have been reached the drugs market throughout history and the recent years have witnessed a significant increase in the use of prodrugs as a replacement of their parent drugs for an efficient treatment of various ailment.

METHODS

A Scan conducted to find recent approved prodrugs and prodrugs in development.

RESULTS

Selected prodrugs were reported and categorized in accordance to their target systems.

CONCLUSIONS

the prodrug approach has shown many successes and still remains a viable and effective approach to deliver new active agents. This conclusion is supported by the recent approved prodrugs and the scan of clinical trials conducted between 2013-2018.

Comparative evaluation of Latanoprostene Bunod, Timolol Maleate, and latanoprost Ophthalmic Solutions to assess their safety and efficacy in lowering intraocular pressure for the management of Open-Angle Glaucoma

OBJECTIVES

Timolol maleate has been reported to be a safer intraocular pressure (IOP) lowering treatment than latanoprost. The United States Food and Drug Administration approved latanoprostene bunod, a nitric oxide-donating prodrug of latanoprost, for lowering IOP. This study compared the safety and efficacy of latanoprost, latanoprostene bunod, and timolol maleate in patients with open-angle glaucoma.

METHODS

Patients who received latanoprost eye drops once daily in the evening were included in the latanoprost Ophthalmic Solutions (LP) cohort (n=104). Those who received latanoprostene bunod eye drops once daily in the evening were included in the Latanoprostene Bunod (LB) cohort (n=94). Those who received timolol eye drops twice daily were included in the Timolol Maleate (TM) cohort (n=115). All treatments were administered to the affected eye(s) for 3 months. Informed Consent has been taken from each participant before the trial.

RESULTS

At the end of 3 months of treatment, latanoprost, latanoprostene bunod, and timolol were all successful in reducing IOP. The LB cohort had the highest reduction in IOP, compared to the LP and TM cohorts. All treatments had some common adverse ocular effects.

CONCLUSION

Latanoprostene bunod was superior to latanoprost and timolol for the treatment of open-angle glaucoma.

New glaucoma medications: latanoprostene bunod, netarsudil, and fixed combination netarsudil-latanoprost

Reduction of intraocular pressure is the only proven method to treat glaucoma. Initial treatment of glaucoma commonly involves using anti-glaucoma medications either as monotherapy or combination therapy. Studies on aqueous humour dynamics have contributed to our understanding of aqueous outflow mechanisms that have led to the discovery of new drugs. Three new drugs (latanoprostene bunod 0.24%, netarsudil 0.02%, and fixed combination netarsudil 0.02% -latanoprost 0.005%) have been introduced recently in the market with novel mechanisms of action. Latanoprostene bunod 0.024% is a nitric oxide-donating prostaglandin F2α analogue which increases the aqueous outflow both by uveoscleral and trabecular pathways. Netarsudil 0.02% is a potent Rho kinase/norepinephrine transporter inhibitor acting by increasing the trabecular outflow, decreasing the aqueous production, and possibly decreasing the episcleral venous pressure. This review highlights the role of these drugs in the management of glaucoma, with an overview of the major clinical trials on their efficacy, safety, and tolerability.

Causative glaucoma treatment: promising targets and delivery systems

Glaucoma is one of the most common causes of blindness worldwide. Elevated intraocular pressure (IOP) is the major modifiable risk factor of the disease. Conventional therapy suffers from poor compliance, low bioavailability, and the lack of causative treatment options. To improve therapeutic success, it is crucial to identify major mediators of pathological changes associated with elevated IOP and to intervene at the molecular level. Here, we discuss relevant key functions of transforming growth factor-β2 (TGF-β2), connective tissue growth factor (CTGF), integrins, Rho-associated kinase (ROCK), and nitric oxide (NO) with regard to the onset of glaucoma, highlighting new drug delivery approaches for causative treatment.

Latanoprostene bunod ophthalmic solution 0.024% in the treatment of open-angle glaucoma: design, development, and place in therapy

Latanoprostene bunod (LBN) 0.024%, a modified prostaglandin analog, was approved on November 2, 2017, for the reduction of IOP in patients with open-angle glaucoma (OAG) or ocular hypertension (OHT). LBN works by combining the IOP-lowering effects of the prostaglandin analogs (through the uveoscleral pathway) with nitric oxide-induced relaxation of the trabecular meshwork and Schlemm’s canal. Nitric oxide-induced relaxation of the trabecular meshwork and Schlemm’s canal leads to increased outflow through the trabecular meshwork and thus lowering of IOP. LBN has now been shown in multiple clinical studies to be effective and safe. In this article, we summarize the clinical trials that led to LBN’s approval as well as the comparative studies that have been done to evaluate the efficacy of this drug as compared to other US Food and Drug Administration (FDA)-approved therapies for OAG and OHT. We then review the side effects of treatment that were seen in each of these studies. Finally, we will attempt to discuss the place of this drug in therapy for patients with OAG.

Glaucoma - Next Generation Therapeutics: Impossible to Possible

The future of next generation therapeutics for glaucoma is strong. The recent approval of two novel intraocular pressure (IOP)-lowering drugs with distinct mechanisms of action is the first in over 20 years. However, these are still being administered as topical drops. Efforts are underway to increase patient compliance and greater therapeutic benefits with the development of sustained delivery technologies. Furthermore, innovations from biologics- and gene therapy-based therapeutics are being developed in the context of disease modification, which are expected to lead to more permanent therapies for patients. Neuroprotection, including the preservation of retinal ganglion cells (RGCs) and optic nerve is another area that is actively being explored for therapeutic options. With improvements in imaging technologies and determination of new surrogate clinical endpoints, the therapeutic potential for translation of neuroprotectants is coming close to clinical realization. This review summarizes the aforementioned topics and other related aspects.

Local Delivery and Sustained-Release of Nitric Oxide Donor Loaded in Mesoporous Silica Particles for Efficient Treatment of Primary Open-Angle Glaucoma

Nitric oxide (NO) donors are ideal drug candidates for reducing intraocular pressure in the treatment of glaucoma. However, poor cornea penetration, short duration of efficacy, and narrow therapeutic index of most NO donors obstruct their clinical applications in glaucoma treatment. This study reports a novel NO donor delivery system based on mesoporous silica nanoparticles that can readily overcome the above difficulties and deliver the NO-donating drug sodium nitroprusside to the target tissues (trabecular meshwork and Schlemm's canal). Mesoporous silica nanoparticles loaded with sodium nitroprusside can produce more exogenous NO and sustain higher NO concentration in animal eye models, which significantly extend the duration of intraocular pressure reduction from 3 to 48 h with only 1/40 of the dose of sodium nitroprusside solution. These findings open up the possibility of mesoporous silica nanoparticles loading sodium nitroprusside for effective management of ocular hypertension.

Investigational drugs targeting prostaglandin receptors for the treatment of glaucoma

INTRODUCTION

Prostaglandin F2α analogs were the first prostaglandin agonists introduced for glaucoma treatment. Thanks to their efficacy and favorable tolerability they set a high bar in competition, with a resultant paucity in new hypotensive drug development for many years. However, the scientific community has shown recently a new interest in exploring new options for glaucoma treatment, generating a remarkable incentive in the marketplace for new drugs.

AREAS COVERED

This article reviews agents targeting prostaglandin receptors that are currently being investigated for glaucoma treatment. We searched published literature for agonists targeting all subtypes of prostaglandin receptors found in ocular tissues. EP and FP receptor agonists are currently in the spotlight of clinical research, while less attention is paid in DP receptor agonists.

EXPERT OPINION

Prostaglandin analogs, targeting different and combinations of receptor subtypes and compounds that exhibit additivity to commonly prescribed medications seem to be highly promising options. New treatments need to be safe, more effective, superior to existing therapies, tolerable and cost-effective. New generation compounds with multiple mechanisms of action or multiagent formulations are vigorously being investigated and generated in laboratories around the world.