Review of clinical outcomes of a cationic emulsion tear substitute in patients with dry eye disease

First-line options for the treatment of dry eye disease (DED) rely on artificial tears (ATs), among which cationic emulsion (CE)-based ATs have been developed in order to mimic the healthy tear film for an improved restoration of the ocular surface homeostasis. In this review, we describe the outcomes reported in several studies, assessing the mode of action, ocular tolerance and clinical performance of a CE-based AT. Pilot studies have revealed that CE-based ATs can increase the volume and stability of the tear film while limiting its evaporation rate. Larger studies have demonstrated that CE-based ATs play a significant role in the improvement of both objective and subjective DED parameters, including superior efficacy on DED symptoms compared to several other available AT formulation types. Concomitantly, CE-based ATs have been shown to help patients to prevent or recover from corneal defects associated with refractive surgery. These positive outcomes on ocular surface epithelia are likely due to the combination of unique rheological behaviour and intrinsic anti-inflammatory properties. Based on all clinical findings, CE-based ATs represent a valuable treatment option for patients with various etiologies of DED including evaporative forms and would deserve evaluation of benefits in other surgical intervention types triggering DED.

Use of a Cationic Emulsion of Latanoprost to Treat Glaucoma Patients with Ocular Surface Disease: A Preclinical Review

Prostaglandin analogue topical medications are one of the most effective therapeutic approaches for the chronic management of glaucoma and ocular hypertension, through the reduction of elevated intra ocular pressure (IOP). While many of the first generations of anti-glaucoma eye drops were preserved with benzalkonium chloride, their repeated use may induce chronic ocular surface toxicity that leads to ocular surface disease (OSD) signs and symptoms. As a result, soft-preservatives and preservative-free formulations have been developed with the goal to avoid the long-term iatrogenic toxicity of the preservative agents. In addition, it has been suggested that OSD and its associated inflammation may negatively impact the efficacy of the IOP-lowering medications, including treatment adherence and compliance. Hence, it may be particularly interesting that glaucoma medications can concomitantly protect and "heal" the ocular surface and its environment while lowering elevated IOP, for the greater benefit of glaucoma patients. The objective of the present review is to briefly present the preclinical data of the cationic oil-in-water emulsion of latanoprost (latanoprost-CE) to shed some light on its mechanisms of action. It overall supports the following hypothesis: the restoration of a healthy ocular surface environment and treatment of the OSD signs and symptoms will allow for an improved elevated IOP reduction and glaucoma management. This would be achieved with a once daily dosing regimen to preserve glaucoma patients' vision, ocular surface, and quality-of-life and wellness.

Assessment of the efficacy of 0.1% cyclosporine A cationic emulsion in the treatment of dry eye disease during COVID-19 pandemic

Objective: To assess the efficacy of 0.1% cyclosporine A (CsA) cationic emulsion (CE) in the treatment of dry eye disease (DED) in terms of ocular surface disease index (OSDI). Methods: DED patients with corneal fluorescein staining grade (CFS) ≤ 3 on the Oxford scale and Schirmer test score < 10 mm/ 5 min were enrolled for once-daily CsA use in this observational, prospective, one-center study. Efficacy of CE at 30, 60, and 90-day follow-up visit was evaluated using OSDI questionnaire. Both the overall OSDI score and the outcomes for all subscales - ocular symptoms (OS), vision-related function (VRF) and environmental triggers (ET) were considered. Results: Twelve patients (10 women and 2 men), whose baseline OSDI ranged between 27.08 and 70.03 mm (48.2 ± 11.8), were included. Their achieved mean scores for subscales such OS, VRF and ET were 66.6 ± 16.8, 42.2 ± 12.0 and 42.2 ± 12.5, respectively. Statistically significant results were obtained after 30 days for OSDI (45.5 ± 10.0; p=0.011), whereas after 90 days for both OSDI (35.4 ± 7.4; p=0.003) and OS (47.2 ± 10.9; p=0.005), VRF (30.5 ± 6.1; p=0.003) and ET (33.3 ± 11.2; p=0.008). Conclusions: CsA CE significantly reduced symptoms of patients with DED. Recovery was the most successful after 90 days of treatment and included OSDI, OS, VRF and ET. Abbreviations: CE = cationic emulsion, CFS = corneal fluorescein staining, CsA = cyclosporine A, DED = dry eye disease, ET = environmental triggers, OS = ocular symptoms, OSDI = ocular surface disease index, VRF = vision-related function.

Nonclinical Safety Assessment of Lipid Nanoparticle-and Emulsion-Based Self-Amplifying mRNA Vaccines in Rats

Vaccines containing mRNA with the capacity to self-amplify represent an alternative to the mRNA vaccines that came to prominence during the COVID-19 pandemic. To gain further insights on the safety profile of self-amplifying mRNA- (SAM-) vaccines, this preclinical toxicology study in rats evaluated the effect of (i) the type of delivery system (lipid nanoparticle [LNP] vs cationic nano-emulsion [CNE]); (ii) antigen-encoding sequence (rabies glycoprotein G vs SARS-CoV-2 Spike); and (iii) RNA amplification. Further analyses also evaluated gene expression in peripheral blood after vaccination, and the biodistribution of vaccine RNA. The SAM vaccines administered as two doses 2-weeks apart had acceptable safety profiles in rats, with respect to clinical signs, blood biochemistry, and macroscopic and microscopic pathology. A transient increase in ALT/AST ratio occurred only in female rats and in the absence of muscle and liver damage was dependent on RNA amplification and appeared related to the greater quantities of vaccine RNA in the muscle and livers of female rats vs male rats. The RNA and delivery-vehicle components, but not the nature of the antigen-coding sequence or the requirement for RNA amplification, affected aspects of the stimulation of innate-immune activity, which was consistent with the transient activation of type I and type II interferon signaling. The delivery vehicle, LNP, differed from CNE as vaccine RNA in CNE compositions appeared independently to stimulate innate-immune activity at 4 hours after vaccination. Our analysis supports further studies to assess whether these differences in innate-immune activity affect safety and efficacy of the SAM vaccine.

Review of Preclinical Outcomes of a Topical Cationic Emulsion of Cyclosporine A for the Treatment of Ocular Surface Diseases

BACKGROUND

Cyclosporine A (CsA) has been used as a topical treatment for various ocular surface diseases including dry eye disease (DED). Several CsA formulations are available as solutions or emulsions.

PURPOSE

This review describes the development and the preclinical testing of a cationic oil-in-water emulsion of CsA (CE-CsA) in terms of pharmacodynamics, pharmacokinetics, and ocular tolerance. Due to the cationic charge, CE electrostatically interacts with the negatively-charged ocular surface, improving its residence time. Compared to other CsA formulations, CE-CsA and CE itself were found to reduce the signs and symptoms of DED, by restoring tear film stability and properties, and inhibiting the expression and secretion of pro-inflammatory factors. No delay in wound healing nor ocular toxicity were observed using CE formulations.

CONCLUSION

these findings indicate that the type of vehicle can significantly affect the performance of eye drops and play an ancillary role in DED treatment. CE appears as a promising strategy to deliver drugs to the ocular surface while maintaining its homeostasis.

Comparative analysis of 0.1% cyclosporin A cationic emulsion and 0.05% cyclosporin A emulsion in murine dry eye cases with different severities

Dry eye (DE), especially severe DE (SDE), can cause ocular surface defects and reduce the patient's quality of life. Several clinical studies have shown that 0.1% cyclosporin A cationic emulsion (CsA CE) could decrease corneal damage. However, no experimental study has reported the effect of 0.1% CsA CE on SDE. The present study aimed to compare the efficacy of 0.1% CsA CE with that of 0.05% CsA emulsion for ocular surface damage and inflammation in the cases of murine DE with different severities. Following exposure to desiccating stress and subcutaneous injection of scopolamine for 5 days, C57BL/6 female mice were divided into SDE and non-SDE (NSDE) groups based on corneal fluorescein staining scores (CFSs). Mice from both groups were topically treated with 0.05% CsA emulsion or 0.1% CsA CE for 10 days. The results demonstrated that 0.1% CsA CE-treated mice in the SDE and NSDE groups exhibited significant improvements in all the clinical and experimental parameters. Furthermore, the CFS of 0.1% CsA CE-treated mice in the SDE group was lower compared with that of the 0.05% CsA-treated mice. In addition, in the SDE group, 0.1% CsA CE-treated mice had significantly lower levels of nuclear factor-κB activation, inflammatory infiltrations and apoptosis on the ocular surface, and they also exhibited higher conjunctival goblet cell density compared with the 0.05% CsA-treated mice. In summary, these findings indicated that 0.1% CsA CE was more effective than topical 0.05% CsA emulsion at improving corneal epithelial injury and decreasing the levels of inflammatory cytokines and T cells in mice with SDE.

Efficacy of Switching from Cyclosporine A 0.05% Anionic Emulsion to Cyclosporine A 0.1% Cationic Emulsion in Patients with Dry Eye Associated with Sjögren's Syndrome

Purpose: To evaluate the clinical efficacy of switching from cyclosporine A (CsA) 0.05% anionic emulsion (CsA AE) to CsA 0.1% cationic emulsion (CsA CE) in patients with dry eye (DE) associated with Sjögren's syndrome (SS). Methods: Forty patients with SS-associated DE who were unresponsive to CsA AE for 6 months were enrolled. After baseline measurements, the CsA AE was switched to CsA CE. The ocular surface disease index (OSDI), Sjögren's International Collaborative Clinical Alliance (SICCA), and Schirmer's test scores and tear film breakup time (TBUT) were evaluated at baseline and 1 and 3 months after switching. Results: Two patients dropped out, and 38 were analyzed. OSDI and SICCA ocular staining scores were significantly reduced at 1 and 3 months after switching, compared with the baseline scores (all P < 0.01). Although no significant changes were noted in the corneal staining scores (CSSs), patients with higher baseline CSS (≥4) showed an improvement in the scores at 1 month (P = 0.03) and 3 months (P = 0.01) after switching. There were no significant changes in TBUT and Schirmer's test scores during the follow-up periods. Conclusions: In patients with SS-associated DE, switching from CsA AE to CsA CE was effective in improving ocular symptoms and conjunctival staining. In addition, corneal staining was decreased in patients with severe keratitis.

Assessment of a Cationic Emulsion to Control the Tear Film Evaporation Rate

PURPOSE

To investigate the effect of a single application of cationic emulsion in controlling tear film evaporation and improving tear quality and quantity.

MATERIALS A METHODS

Twenty male subjects diagnosed with DE were enrolled in the study with an average age of 45.8 ± 6.37 years. The tear film parameters were observed at several time points post-instillation of the cationic emulsion (10, 20, 30, and 60 min). The tear evaporation rate (TER) was measured with a VapoMeter. Noninvasive tear break-up time and meniscus height were assessed using OCULUS Keratograph.

RESULTS

TER decreased by more than 20% at 20, 30, and 60 minutes time points after instillation of single drop of cationic emulsion. Also, a significant improvement in tear film stability was found at all time points following the instillation of cationic emulsion eye drops. The mean tear break-up time increased from 5.55 ± 2.87 to 6.6 ± 4.2 sec at 60 minutes. The maximum increase in tear break-up time occurred at 30 minutes time point. The TMH was also significantly higher post-instillation of oil emulsion eye drops. There was a significant increase in the TMH post-therapy with oil drop at all time points.

CONCLUSION

The overall study findings of this study illustrate that the single application of a cationic emulsion effectively controls tear film evaporation in patients with mild to moderate DEs. The cationic emulsion efficiently enhanced both the tear film stability and the tear meniscus volume.

Ocular surface response of two preservative-free cylcosporine A emulsion eye drops in a mouse model of dry eye

PURPOSE/AIM

Dry eye (DE) disease is a multifactorial disease in which uncontrolled inflammation can lead to corneal epithelium lesions and symptoms of discomfort. The aim of the present study was to evaluate the efficacy of two cyclosporine emulsions in a mouse model of DE with corneal epithelium lesions.

MATERIALS AND METHODS

Six- to 9-week-old female C57BL/6 N mice were housed in a controlled-environment room to induce DE. Following DE development, mice were instilled with: QD 0.1%CsA cationic emulsion (CaEm), BID 0.05%CsA anionic emulsion (AEm), or left untreated. Aqueous tear production and corneal epithelium lesions were assessed throughout the experiment. At the end of the treatment period, left eyes were sampled, fixed, and stained for histology, while the cornea, conjunctiva, and lacrimal gland of right eyes were sampled for transcriptomic analysis.

RESULTS

Corneal lesion scores were reduced by 10.4%, 18.4%, and 10.9% at day 6, 10, and 14, respectively, with CaEm (QD), and by 2.6%, 3.0%, and 5.5% at day 6, 10, and 14, respectively, with AEm (BID). Histology demonstrated that 7 out of 10 DE mice presented moderate to severe ocular lesions, while only 2 and 5 out of 10 mice presented slight to moderate ocular lesions when treated with the CaEm (QD) and AEm (BID), respectively. The transcriptomic profile analysis suggests that a different set of inflammatory genes are modulated in the cornea, conjunctiva, and lacrimal gland upon DE development. In addition, the two emulsions distinctively modulate the gene expression profile.

CONCLUSIONS

This study demonstrates that both emulsions were effective at reducing corneal lesions, with the CaEm (QD) being slightly better than the AEm (BID). Interestingly, this study suggests that ocular tissues may not respond similarly to a dry environment and that a different set of genes is modulated by the two formulations in the ocular tissues.

Cationic Emulsion-Based Artificial Tears as a Mimic of Functional Healthy Tear Film for Restoration of Ocular Surface Homeostasis in Dry Eye Disease

Dry eye disease (DED) is a complex multifactorial disease that affects an increasing number of patients worldwide. Close to 30% of the population has experienced dry eye (DE) symptoms and presented with some signs of the disease during their lifetime. The significant heterogeneity in the medical background of patients with DEs and in their sensitivity to symptoms renders a clear understanding of DED complicated. It has become evident over the past few years that DED results from an impairment of the ocular surface homeostasis. Hence, a holistic treatment approach that concomitantly addresses the different mechanisms that result in the destabilization of the tear film (TF) and the ocular surface would be appropriate. The goal of the present review is to compile the different types of scientific evidence (from in silico modeling to clinical trials) that help explain the mechanism of action of cationic emulsion (CE)-based eye drop technology for the treatment of both the signs and the symptoms of DED. These CE-based artificial tear (AT) eye drops designed to mimic, from a functional point of view, a healthy TF contribute to the restoration of a healthy ocular surface environment and TF that leads to a better management of DE patients. The CE-based AT eye drops help restore the ocular surface homeostasis in patients who have unstable TF or no tears.

Persistence of Efficacy of 0.1% Cyclosporin A Cationic Emulsion in Subjects with Severe Keratitis Due to Dry Eye Disease: A Nonrandomized, Open-label Extension of the SANSIKA Study

PURPOSE

Results from a 6-month double-masked and a 6-month open-label study (SANSIKA) established the efficacy and safety of once-daily 0.1% cyclosporin A cationic emulsion (CsA CE) in severe keratitis due to dry eye disease (DED). This article presents results from the Post-SANSIKA study, a 24-month extension of SANSIKA assessing the sustained efficacy of CsA CE after treatment discontinuation.

METHODS

Time to relapse (corneal fluorescein staining [CFS] score ≥4 [modified Oxford scale]) was assessed after treatment discontinuation in patients from the SANSIKA study who had CFS improvement from a score of 4 to ≤2 after 6 or 12 months of treatment with CsA CE.

FINDINGS

Of 62 patients who achieved a CFS score ≤2 at the end of the SANSIKA study, 38 did not relapse and 24 (39%) relapsed during the 24-month period after CsA CE discontinuation; the latter (relapse) group comprised 35% of patients initially treated with CsA CE for 12 months in SANSIKA versus 47% of those treated for 6 months only. Patients spent the most time during the extension study at CFS scores of 1 or 2 (median duration of 8.5 weeks and 14.7 weeks per year, respectively), indicating marked improvement, and less time at scores of 3, 4, or 5 (median time, 2.0 weeks, 0 weeks, and 0 weeks per year). Of 23 patients eligible for safety analysis (ie, patients who received the study treatment at least once), 12 (52.2%) reported a total of 26 ocular adverse events (AEs). Among these, 5 ocular AEs, reported in 5 patients (21.7%), were considered related to study treatment: 3 events of mild instillation site pain in 3 patients (13.0%) and eye discharge and foreign body sensation, each reported in 1 patient (4.3%). Only 1 systemic AE (nasal congestion), reported in 1 patient (4.3%), was considered related to study treatment. None of the AEs led to treatment discontinuation.

IMPLICATIONS

The majority of patients who discontinued CsA CE after experiencing DED improvement in the SANSIKA study did not experience a relapse in this 24-month follow-up study; these patients spent the most time at CFS scores consistent with marked improvement. CsA CE had a favorable safety/tolerability profile over 2 years. Treatment for up to 12 months with CsA CE provides sustained improvements in patients with severe keratitis due to DED. EudraCT registration no. 2012-002066-12.

Topical ocular 0.1% cyclosporine A cationic emulsion in dry eye disease patients with severe keratitis: experience through the French early-access program

Purpose

The objective of this study was to report the evaluation of efficacy and safety of cyclosporine A cationic emulsion (CsA CE) 0.1% for the treatment of severe keratitis in adults with dry eye disease (DED) in a French early-access program.

Methods

Patients with DED and severe keratitis (corneal fluorescein staining [CFS] score of 3-5 on the Oxford scale and/or the presence of corneal lesions [filaments or ulcers]) were enrolled in a compassionate use program (Authorization for Temporary Use [ATU]) for once-daily CsA CE, which was approved by French health authorities prior to its registration. Efficacy and safety at 1, 3, 6, and 12-month follow-up visits were evaluated.

Results

The ATU cohort (n=1,212; mean age =60.5 years; 79.5% female; 98.1% with severe keratitis; 74.5% with corneal lesions) consisted of 601 CsA-naïve patients and 611 patients treated previously with other CsA formulations. The primary DED etiology was Sjögren's syndrome (48.7%). Clinical benefit could be discerned among 548 evaluable patients from months 1 to 12: keratitis improvement, 44.8% at month 1 and 42.1% at month 12; keratitis stabilization, 47.2% and 45.7%, respectively; symptom improvement, 47.2% and 48.6%; and symptom stabilization, 44.8% and 45.0%. Corneal clearing (CFS score =0) increased from 4.8% (month 1) to 11.4% (month 12). No unexpected safety concerns were identified; instillation site pain (10.2%) and eye irritation (7.8%) were the most common adverse events.

Conclusion

The French ATU cohort provides supportive data on the clinical benefit of CsA CE in improving/stabilizing symptoms and corneal damage in DED patients with severe keratitis in real-world clinical practice.

A comparative review of Haute Autorité de Santé and National Institute for Health and Care Excellence health technology assessments of Ikervis® to treat severe keratitis in adult patients with dry eye disease which has not improved despite treatment with tear substitutes

Background: In 2015, Ikervis® became the only EMA-approved cyclosporine A (CsA) eye-drop for the treatment of severe keratitis in adult patients with dry eye disease, which has not improved despite treatment with tear substitutes. Since the 1980s, CsA has been used empirically for ocular conditions in veterinary medicine then in humans. However, its extremely low aqueous solubility led to its administration in vegetable oils, which is characterized by low ocular availability, poor intraocular penetration, poor tolerability and short shelf-life. Concentrations from 0.05% to 2% are compounded on an industrial scale and reimbursed throughout Europe. In France, Ikervis® has been granted an ASMR score of 5 by HAS, whereas in UK NICE endorsed its use. Objective: To review the dry eye disease environment, its challenges and available treatment options, and compare the NICE and HAS assessments to question HAS' decision to maintain full reimbursement of compounded CsA formulations in the absence of evidence, while reimbursing the EMA-approved drug at 15%.

METHOD

extensive search on PubMED. Results: Comparator selection, composite score assessment and use of CE model are key differentiators. Conclusion: In topical formulations, improvements to the vehicle are key innovations that can bring significant benefits. After the USA, a Compounding Act is needed in Europe.

Cationorm shows good tolerability on human HCE-2 corneal epithelial cell cultures

Preservatives have been for a long time known to cause detrimental effects on ocular surface. Cationorm, a preservative-free compound with electrostatic properties is a novel way to solve the problems encountered with traditional benzalkonium chloride (BAK)-containing eye drops. The aim of this study was to evaluate tolerability of the preservative-free cationic emulsion Cationorm in vitro on corneal epithelial cells. The human corneal epithelial cell (HCE-2) culture line was used to study cellular morphology, cytotoxicity and inflammatory responses after Cationorm diluted 1/10 exposure for 5, 15 and 30 min. Exposures to Systane diluted 1/10 with polyquaternium-1/polidronium chloride 0.001% as preservative, BAK 0.001% or C16 (0.0002%) and normal cell culture medium served as positive and negative references. Cell viability was determined by measuring the release of lactate dehydrogenase (LDH) and mitochondrial dehydrogenase activity was evaluated using 3-(4,5-dimethyldiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The possible induction of apoptosis was analyzed by measuring the activity of caspase-3, and Cell Counting Kit-8 (CCK-8) was used to evaluate the number of viable cells after the exposure to test compounds. Furthermore, the tendency of the test compounds to produce inflammatory reaction was determined by analyzing the production of proinflammatory cytokines IL-6 and IL-8, and DNA binding of the p65 subunit of transcription factor NF-κB was measured from cell lysates. HCE-2 cells showed no morphological changes after the exposure to Cationorm, but in cells exposed to BAK, clear cytoplasm vacuolization and loose cell-cell contacts were observed in transmission (TEM) or scanning (SEM) electron microscopic analyses. Cell viability, as measured with the release of LDH, indicated a time dependent increase in LDH expression after exposure to all test compounds but especially with BAK. Moreover, Cationorm and BAK time-dependently decreased the mitochondrial metabolism to 73% with Cationorm and 53% with BAK from that of the control cells after 30 min exposure in MTT assay. BAK was the only test compound having clear adverse effects on the cell number and metabolism in CCK-8 assay. The activity of caspase-3 did not show significant differences between the groups. Inflammatory response after exposure to Cationorm was significantly lower than after exposure to BAK. There were no significant differences in NF-κB activity between the groups. Diluted Cationorm and Systane with polyquaternium-1/polidronium chloride 0.001% showed good tolerability on HCE-2 cells and thereby provide a clear improvement when compared to BAK-containing eye drop formulations.