Efficacy of HL036 versus Cyclosporine A in the Treatment of Naturally Occurring Canine Keratoconjunctivitis Sicca

Inflammation in Dry Eye Disease-Pathogenesis, Preclinical Animal Models, and Treatments

Dry eye disease (DED) is a rapidly growing ocular surface disease with a significant socioeconomic impact that affects the patients' visual function and, thus, their quality of life. It is distinguished by a loss of tear film homeostasis, leading to tear film instability, hyperosmolarity, ocular surface inflammation, and neurosensory abnormalities, with all of these playing etiological roles in the propagation of the vicious DED circle. While current treatments primarily focus on reducing tear film instability and hyperosmolarity, increasingly more attention is being placed on tackling the underlying inflammation that propagates and potentiates these factors. As such, preclinical models are crucial to further elucidate the DED pathophysiology and develop novel therapeutic strategies. This review outlines the role of inflammation in DED, highlighting related signs and diagnostic tools before focusing on relevant preclinical animal models and potential therapeutic strategies to tackle DED-associated inflammation.

Novel treatments for dry eye syndrome

Dry eye syndrome (DES) is a prevalent and multifactorial disease that leads to a self-perpetuating cycle of inflammation and damage to the ocular surface. This results in symptoms such as redness, burning, and blurred vision, which can negatively affect a patient's quality of life. While treatments are available to manage DES, they only temporarily relieve symptoms. Furthermore, long-term use of certain medications can cause harm to the ocular surface. Therefore, there is a need for safer and effective treatments for DES. This review highlights the latest advancements in DES therapy, providing valuable insights into ongoing efforts to improve patient outcomes.

Treatment of Dry Eye Disease (DED) in Asia: Strategies for Short Tear Film Breakup Time-Type DED

Dry eye disease (DED) is a multifactorial disorder in which tear fluid homeostasis is lost, resulting in increased tear film osmolarity and ocular surface irritation. In Asia, the short tear film breakup time-type DED, which has become a global problem in recent years, is common. While the mainstay of DED treatment in the West is the suppression of inflammation, the first goal of treatment is the stabilization of the tear film in Asia. To date, artificial tears and steroid eye drops have been the main treatment for DED. However, artificial tears require frequent administration of eye drops and thus pose adherence problems, while steroids have problems with side-effects (cataracts, increased intraocular pressure). This review evaluates the new generation therapies in Asia based on what is known about them and demonstrates that they are more effective for DED than traditional therapies such as artificial tears and steroids. Based on considerations, it is proposed that the optimal treatment for the short tear film breakup time-type DED is the initial application of mucin-secretion-enhancing eye drops (long-acting diquafosol) and oral supplements; and if additional treatment is needed, cyclosporine eye drops and the adjunctive therapies presented in this review are added.

Recent advances in drug treatments for dry eye disease

INTRODUCTION

Dry eye disease (DED) is a common ocular condition with a significant impact on patients' quality of life. Conventional treatments include behavioral changes, tear substitutes, and anti-inflammatory agents; however, recent advances in the understanding of DED pathogenesis have opened the way to the development of novel treatment strategies able to target several pathways involved in the onset and persistence of DED.

AREAS COVERED

Literature search was conducted on PubMed and Scopus around the term 'dry eye disease' and others involving its pathophysiology and therapeutic strategy. The primary focus was on recent drugs approved by FDA or under investigation in phase 3 clinical trials. Google and ClinicalTrials.gov were used for obtaining information about the status of FDA approval and ongoing clinical trials.

EXPERT OPINION

Due to its multifaced pathogenesis, DED management is often challenging, and patients' needs are frequently unmet. Recently, several novel treatments have been either FDA-approved or studied in late-phase trials. These novel drugs target-specific biological components of the ocular surface and reduce inflammation and ocular pain. Additionally, new drug delivery systems allow for increased bioavailability, improve effective dosing, and minimize ocular side effects. These advances in drug therapies show real promise for better management of DED patients.

TNF-α inhibitor tanfanercept (HBM9036) improves signs and symptoms of dry eye in a phase 2 trial in the controlled adverse environment in China

Purpose

This study evaluated the clinical safety and efficacy of tanfanercept (HBM9036) ophthalmic solution as a novel treatment for dry eye disease (DED) in a controlled adverse environment (CAE) study conducted in China.

Methods

In a single-center, double-masked, randomized, placebo-controlled study, 100 patients received 0.25% tanfanercept, or placebo, twice daily for eight weeks. A mobile international CAE^® DE Model was used for patient selection with a standardized challenge endpoint. Primary efficacy endpoint was fluorescein inferior corneal staining score (ICSS) pre- to post-CAE challenge from baseline. Secondary endpoints included Schirmer’s Tear Test, Tear-Film Break-Up Time, Ocular Discomfort Score, Ora Calibra^® Ocular Discomfort and 4-Symptom Questionnaire, total corneal staining score (TCSS), and drop comfort. Signs and symptoms were assessed both pre- and post-CAE to evaluate the efficacy of tanfanercept on both environmental and CAE endpoints.

Results

The tanfanercept treatment group showed improvement in ICSS pre- to post-CAE change from baseline scores when compared to placebo (− 0.61 ± 0.11 and − 0.54 ± 0.11, respectively; mean difference = 0.07, p = 0.65). TCSS pre–post-CAE change from baseline scores was also in favor of active when compared to placebo (− 1.03 ± 0.21 and − 0.67 ± 0.21, respectively; mean difference = 0.37, p = 0.23). Schirmer’s score improvement was demonstrated in favor of active (1.87 ± 0.62 mm) as compared to placebo (1.28 ± 0.62 mm; mean difference = 0.59 mm, p = 0.50). Change from baseline in mean Tear-Film Break-up Time favored active treatment over placebo (mean difference = 1.21 s, p = 0.45). Notably, the tanfanercept showed more obvious benefits for each DED sign in a subgroup of subjects ≥ 35 years of age. Tanfanercept was well tolerated with no serious adverse events occurring during the study.

Conclusion

Tanfanercept demonstrated improvements in favor of active as compared to placebo in the signs of DED, being safe and well tolerated. These data support further evaluation of tanfanercept for the treatment of DED in China.

Trial registration

This study was retrospectively registered at ClinicalTrials.gov (NCT04092907) on September 17, 2019.

Oral mucosa transplantation may improve tear film osmolarity in dogs with keratoconjunctivitis sicca - a preliminary study

ABSTRACT The objective of this study was to evaluate the use of cyclosporine 1% alone or associated with oral mucosa transplantation (OMT) in dogs with dry keratoconjunctivitis (KCS). Schirmer Tear Test (STT-1) and Tear Film Osmolarity (TFO) were measured in both eyes of 30 adult dogs (before and 45 days after treatment. The animals were divided into three groups (10 dogs for group): control (normal dogs), group I (GI, treated with 1% cyclosporine alone), and group II (GII, treated with 1% cyclosporine and OMT). All STT-1 and TFO values were subjected to the Shapiro-Wilk normality test, and all were normally distributed. STT-1 and TFO values before and after treatment were subjected to the T-Student Test. The STT‐1 and TFO values of the right eye were subjected to Repeated Measures ANOVA followed by a Tukey Test for comparison between groups I and II. Means with a value of p≤0.05 were considered significant. There was a decreased osmolarity in both groups after treatment. Mean osmolarity in GII (322.60±16.56 mOsm/L) was significantly lower than GI (336.40±5.66 mOsm/L). The OMT associated with cyclosporine 1% improved the osmolarity of the tear film in dogs with KCS with a seeming synergism between the clinical and surgical treatments.

Emerging therapies for dry eye disease

INTRODUCTION

Dry Eye Disease (DED) is defined as a multifactorial disease of the ocular surface characterized by a loss of homeostasis of the tear film, and a vicious cycle of inflammation on the ocular surface. Despite its high prevalence and standing as one of the most common eye conditions seen by practitioners, the current treatment options available to patients have not proven adequate.

AREAS COVERED

This review will discuss the burden of DED, its pathophysiology, as well as emerging therapies. These therapies include immunosuppressants, immunomodulators, anti-inflammatory drugs, and corticosteroids. The mechanisms of these drugs will be discussed, as well as their phase of development and results from recent clinical trials. The literature search was performed using PubMed, Cochrane Library, Web of Science, ClinicalTrials.gov, and the Springer AdisInsight database.

EXPERT OPINION

The optimal therapy for DED is associated with improved bioavailability, minimal ocular side effects, and effective dosing. The ideal treatment has not yet been established, but this paper outlines a number of promising therapies. Continued development of therapies targeting the inflammation cascade, as well as the establishment of objective markers to quantify DED severity, are important aspects in the progression of treatment.