Biosimilars for Retinal Diseases: An Update

Biosimilars of anti-vascular endothelial growth factor for ophthalmic diseases: A review

The development of intravitreally injected biologic medicines (biologics) acting against vascular endothelial growth factor (VEGF) substantially improved the clinical outcomes of patients with common VEGF-driven retinal diseases. The relatively high cost of branded agents, however, represents a financial burden for most healthcare systems and patients, likely resulting in impaired access to treatment and poorer clinical outcomes for some patients. Biosimilar medicines (biosimilars) are clinically equivalent, potentially economic alternatives to reference products. Biosimilars approved by leading health authorities have been demonstrated to be similar to the reference product in a comprehensive comparability exercise, generating the totality of evidence necessary to support analytical, pre-clinical, and clinical biosimilarity. Anti-VEGF biosimilars have been entering the field of ophthalmology in the US since 2022. We review regulatory and scientific concepts of biosimilars, the biosimilar development landscape in ophthalmology, with a specific focus on anti-VEGF biosimilars, and discuss opportunities and challenges facing the uptake of biosimilars.

Visual Outcome and Fluid Changes Between Eyes With Polypoidal Choroidal Vasculopathy Receiving Biosimilar CKD-701 or Reference Ranibizumab Therapy: A Post Hoc Analysis of a Phase 3 Randomized Clinical Trial

PURPOSE

To compare the visual outcome and fluid features of a proposed biosimilar, CKD-701, versus the reference ranibizumab in eyes with polypoidal choroidal vasculopathy (PCV).

METHODS

This was a post hoc analysis of a phase 3 randomized clinical trial assessing the efficacy and safety of CKD-701 and ranibizumab. A total of 73 PCV eyes were assigned randomly to either CKD-701 (36 eyes) or ranibizumab (37 eyes). The mean changes in best-corrected visual acuity (BCVA), central retinal thickness (CRT), pigment epithelial detachment (PED) volume, and fluid features were compared.

RESULTS

After three loading injections, the mean change in BCVA (letters) was +7.50 in the CKD-701 group and +6.32 in the ranibizumab group (p = .447). The changes in CRT and PED volume of the CKD-701 group (-107.25 ± 102.66 μm and -0.22 ± 0.46 mm3) were similar to those of the ranibizumab group (-96.78 ± 105.00 μm and -0.23 ± 0.54 mm3) (p = .668 and p = .943, respectively). Proportions of eyes with subretinal, intraretinal and sub-retinal pigment epithelium (RPE) fluids after three loading injections were not different between CKD-701 group (33.3%, 13.9% and 42.9%) and ranibizumab group (51.4%, 16.2% and 40.0%) (p = .071, p = 1.000 and p = .808). The visual and anatomical changes were similar between two groups at month 6 and 12 (all, p > .05).

CONCLUSION

Biosimilar CKD-701 monotherapy resulted in comparable visual and anatomical changes to those achieved with reference ranibizumab in PCV eyes.

Biosimilars for retinal diseases: United States-Europe awareness survey (Bio-USER - survey)

PURPOSE

To assess the awareness of biosimilar intravitreal anti-VEGF agents among retina specialists practicing in the United States (US) and Europe.

METHODS

A 16-question online survey was created in English and distributed between Dec 01, 2021 and Jan 31, 2022. A total of 112 respondents (retinal physicians) from the US and Europe participated.

RESULTS

The majority of the physicians (56.3%) were familiar with anti-VEGF biosimilars. A significant number of physicians needed more information (18.75%) and real world data (25%) before switching to a biosimilar. About one half of the physicians were concerned about biosimilar safety (50%), efficacy (58.9 %), immunogenicity (50%), and their efficacy with extrapolated indications (67.8 %). Retinal physicians from the US were less inclined to shift from off-label bevacizumab to biosimilar ranibizumab or on-label bevacizumab (if approved) compared to physicians from Europe (p=0.0001). Furthermore, physicians from the US were more concerned about biosimilar safety (p=0.0371) and efficacy compared to Europe (p= 0.0078).

CONCLUSIONS

The Bio-USER survey revealed that while the majority of retinal physicians need additional information regarding the safety, efficacy and immunogenicity when making clinical decisions regarding their use. Retinal physicians from US are more comfortable in continuing to use off-label bevacizumab compared to physicians from Europe.

Systematic review of efficacy and meta-analysis of safety of ranibizumab biosimilars relative to reference ranibizumab anti-VEGF therapy for nAMD treatment

TOPIC

This systematic review and meta-analysis provides a summary of the efficacy and safety of ranibizumab biosimilars relative to reference ranibizumab anti-vascular endothelial growth factor (VEGF) therapy for the treatment of neovascular age-related macular degeneration (nAMD).

METHODS

We conducted systematic searches from January 2003 to August 2022 on Ovid MEDLINE, EMBASE and the Cochrane Controlled Register of Trials. We included studies reporting changes in early treatment diabetic retinopathy study-measured best-corrected visual acuity (BCVA), number of patients who lost or gained more than 15 letters in BCVA from baseline, changes in retinal thickness and adverse events between treatment arms. The following studies were excluded: studies that did not report visual outcomes following biosimilar and reference ranibizumab intravitreal injections, study arms combining anti-VEGF agents with laser or steroid injections, sham injections as a control comparator, studies without English full texts and non-comparative, observational study design.

RESULTS

Five studies reported on four randomised controlled trials (RCTs) and 1544 eyes at baseline were included in this systematic review and meta-analysis. The studies in our systematic review found no significant differences between reference ranibizumab and ranibizumab biosimilar medications (FYB201, SB11, RanizuRel and Lupin's ranibizumab) for visual and anatomical outcomes. No significant differences were detected between biosimilar and reference ranibizumab for treatment emergent adverse events (risk ratio, RR 1.06, 95% CI (0.91 to 1.23), p=0.45, I²=52%) or IOP-related adverse events with significant heterogeneity (RR 2.59, 95% CI (0.11 to 62.25), p=0.56, I²=76%).

CONCLUSION

This systematic review of four RCTs demonstrated no significant difference in visual outcomes, retinal thickness outcomes, as well as meta-analysis of adverse events between biosimilar and reference ranibizumab therapies for nAMD treatment.

Suppressing Inflammation for the Treatment of Diabetic Retinopathy and Age-Related Macular Degeneration: Dazdotuftide as a Potential New Multitarget Therapeutic Candidate

Diabetic retinopathy (DR) and age-related macular degeneration (AMD) are major causes of blindness globally. The primary treatment option for DME and neovascular AMD (nAMD) is anti-vascular endothelial growth factor (VEGF) compounds, but this treatment modality often yields insufficient results, and monthly injections can place a burden on the health system and patients. Although various inflammatory pathways and mediators have been recognized as key players in the development of DR and AMD, there are limited treatment options targeting these pathways. Molecular pathways that are interlinked, or triggers of multiple inflammatory pathways, could be promising targets for drug development. This review focuses on the role of inflammation in the pathogenesis of DME and AMD and presents current anti-inflammatory compounds, as well as a potential multitarget anti-inflammatory compound (dazdotuftide) that could be a candidate treatment option for the management of DME and AMD.

The state-of-the-art pharmacotherapeutic management of neovascular age-related macular degeneration

INTRODUCTION

Age-related macular degeneration (AMD) is a major cause of central visual loss in the developed world. Although the pathogenesis is not fully understood, vascular endothelial growth factor (VEGF) is considered the most important growth factor involved in angiogenesis and exudation in neovascular AMD eyes. Advances in anti-VEGF agents have changed the treatment approach for wet AMD, allowing better outcomes in visual acuity and retinal anatomy.

AREAS COVERED

The present review describes the main pharmacological and clinical characteristics of anti-VEGF drugs, focusing firstly on the molecules commonly in use and then on the new candidate therapies. We performed a comprehensive literature search using the PubMed database from 1 January 1993 to 1 June 2022, with search terms including anti-VEGF, biosimilar, neovascular macular degeneration, AMD, and safety.

EXPERT OPINION

The management of AMD is still onerous for both the physician and patient due to the great number of required injections. Current research is underway to resolve not only the economic burden but also the discomfort of patients, aiming to develop a drug with a different or a multiple target, increasing the potency whilst maintaining a good safety profile. Furthermore, clinical research is currently investigating different forms of drug administration.

Efficacy and safety of a new ranibizumab biosimilar CKD-701 using a pro re nata treatment regimen in neovascular age-related macular degeneration: A phase 3 randomized clinical trial

PURPOSE

This study aimed to establish the efficacy, safety, and immunogenicity equivalence of the proposed biosimilar CKD-701 with the reference ranibizumab in patients with treatment-naïve neovascular age-related macular degeneration (nAMD).

PATIENTS AND METHODS

A total of 312 participants with active subfoveal choroidal neovascularization were randomly assigned to either the CKD-701 (n = 156) or reference ranibizumab (n = 156) arms. The initial 3-month loading intraocular injections were followed by pro re nata (PRN) dosing for 9 months. The primary outcome was the proportion of patients with less than 15-letters of corrected visual acuity (BCVA) loss at 3 months visit (one month after last loading injection) compared to the baseline time point. The presence of retinal fluid, and changes in BCVA and central retinal thickness (CRT) were assessed as secondary efficacy outcomes. Immunogenicity and safety were evaluated in both treatment arms.

RESULTS

In the CKD-701 arm, 143 (97.95%) patients lost <15 letters in the BCVA at 3 months compared to 143 (98.62%) in the reference arm (P = 0.67). The BCVA improved with a mean improvement of +7.0 (CKD-701) and +6.2 (ranibizumab) letters at 3 months (P = 0.43). The least-squares mean (SE) changes in CRT at 3 months from the baseline were -119.3 (12.0) μm and -124.5 (11.9) μm in the CKD-701 and ranibizumab groups, respectively (P = 0.74). The proportion of participants with subretinal or intraretinal fluid at 3, 6, and 12 months was similar between the study arms. The number (SE) of injections were 8.36 (3.13) in the CKD-701 and 8.26 (2.92) in ranibizumab (P = 0.62). The occurrence of adverse events and antidrug antibody in the study arms were also not statistically different.

CONCLUSION

CKD-701 is a biosimilar to the reference ranibizumab in terms of efficacy, safety, and immunogenicity for the treatment of patients with nAMD. Moreover, improvement and maintenance of visual outcome were achieved through PRN regimen.

Diabetic Macular Edema: Current Understanding, Molecular Mechanisms and Therapeutic Implications

Diabetic retinopathy (DR), with increasing incidence, is the major cause of vision loss and blindness worldwide in working-age adults. Diabetic macular edema (DME) remains the main cause of vision impairment in diabetic patients, with its pathogenesis still not completely elucidated. Vascular endothelial growth factor (VEGF) plays a pivotal role in the pathogenesis of DR and DME. Currently, intravitreal injection of anti-VEGF agents remains as the first-line therapy in DME treatment due to the superior anatomic and functional outcomes. However, some patients do not respond satisfactorily to anti-VEGF injections. More than 30% patients still exist with persistent DME even after regular intravitreal injection for at least 4 injections within 24 weeks, suggesting other pathogenic factors, beyond VEGF, might contribute to the pathogenesis of DME. Recent advances showed nearly all the retinal cells are involved in DR and DME, including breakdown of blood-retinal barrier (BRB), drainage dysfunction of Müller glia and retinal pigment epithelium (RPE), involvement of inflammation, oxidative stress, and neurodegeneration, all complicating the pathogenesis of DME. The profound understanding of the changes in proteomics and metabolomics helps improve the elucidation of the pathogenesis of DR and DME and leads to the identification of novel targets, biomarkers and potential therapeutic strategies for DME treatment. The present review aimed to summarize the current understanding of DME, the involved molecular mechanisms, and the changes in proteomics and metabolomics, thus to propose the potential therapeutic recommendations for personalized treatment of DME.

Effects of Flow Hydrodynamics and Eye Movements on Intraocular Drug Clearance

New in vitro prototypes (PK-Eye™) were tested with and without eye movement to understand diffusion and convection effects on intraocular clearance. Port placement in front ((i) ciliary inflow model) and behind the model lens ((ii) posterior inflow model) was used to study bevacizumab (1.25 mg/50 µL) and dexamethasone (0.1 mg/100 µL) in phosphate-buffered saline (PBS, pH 7.4) and simulated vitreal fluid (SVF). Dexamethasone was studied in a (iii) retinal-choroid-sclera (RCS) outflow model (with ciliary inflow and two outflow pathways). Ciliary vs. posterior inflow placement did not affect the half-life for dexamethasone at 2.0 µL/min using PBS (4.7 days vs. 4.8 days) and SVF (4.9 days with ciliary inflow), but it did decrease the half-life for bevacizumab in PBS (20.4 days vs. 2.4 days) and SVF (19.2 days vs. 10.8 days). Eye movement only affected the half-life of dexamethasone in both media. Dexamethasone in the RCS model showed approximately 20% and 75% clearance from the RCS and anterior outflows, respectively. The half-life of the protein was comparable to human data in the posterior inflow model. Shorter half-life values for a protein in a ciliary inflow model can be achieved with other eye movements. The RCS flow model with eye movement was comparable to human half-life data for dexamethasone.

miR-125a-5p attenuates macrophage-mediated vascular dysfunction by targeting Ninjurin1

Ninjurin1 (Ninj1), an adhesion molecule, regulates macrophage function in hyaloid regression, multiple sclerosis, and atherosclerosis. However, its biological relevance and the mechanism underlying its function in vascular network integrity have not been studied. In this study, we investigated the role of Ninj1 in physiological (postnatal vessel formation) and pathological (endotoxin-mediated inflammation and diabetes) conditions and developed a strategy to regulate Ninj1 using specific micro (mi)RNAs under pathological conditions. Ninj1-deficient mice exhibited decreased hyaloid regression, tip cell formation, retinal vascularized area, recruitment of macrophages, and endothelial apoptosis during postnatal development, resulting in delayed formation of the vascular network. Five putative miRNAs targeting Ninj1 were selected using the miRanda algorithm and comparison of expression patterns. Among them, miR-125a-5p showed a profound inhibitory effect on Ninj1 expression, and miR-125a-5p mimic suppressed the cell-to-cell and cell-to-matrix adhesion of macrophages and expression of pro-inflammatory factors mediated by Ninj1. Furthermore, miR-125a-5p mimic inhibited the recruitment of macrophages into inflamed retinas in endotoxin-induced inflammation and streptozotocin-induced diabetes in vivo. In particular, miR-125a-5p mimic significantly attenuated vascular leakage in diabetic retinopathy. Taken together, these findings suggest that Ninj1 plays a pivotal role in macrophage-mediated vascular integrity and that miR-125a-5p acts as a novel regulator of Ninj1 in the management of inflammatory diseases and diabetic retinopathy.

An Introduction to Biosimilars for the Treatment of Retinal Diseases: A Narrative Review

Biological therapies have revolutionized the treatment of disease across a number of therapeutic areas including retinal diseases. However, on occasion, such treatments may be relatively more expensive compared to small molecule therapies. This can restrict patient access and treatment length leading to suboptimal clinical outcomes. Several biosimilar candidates of ranibizumab and aflibercept are currently in development and the first biosimilar of ranibizumab received EMA approval in August and FDA approval in September 2021. Biosimilars are biological medicines that are highly similar to an already-approved biological medicine (reference product). The physicochemical and clinical similarity of a biosimilar is determined by a rigorous analytical and clinical program, including extensive pharmacokinetic and pharmacodynamic analysis with phase III equivalence studies where appropriate. These phase III studies are carried out in a patient population that is representative of all of the potential approved therapeutic indications of the originator product and the most sensitive for detecting potential differences between the biosimilar and the reference product. Biosimilars have been used successfully across a wide range of therapeutic areas for the past 15 years where they have achieved substantial cost savings that can be reinvested into healthcare systems without affecting the quality of patient care. The current review provides an introduction to biosimilars with the aim of preparing retinal specialists for discussing these products with their patients.

Ranizurel safety evaluation in real-world -(RaSER) study

PURPOSE

To assess the early real-world clinical outcomes regarding safety and efficacy after ranizurel administration.

METHODS

A retrospective, consecutive, interventional, uncontrolled, multi-centre study was conducted incorporating data from four centres in India. 22 eyes with variable indications were included and all patients were treated with at least one intravitreal injection of ranizurel 0.5 mg between January 2021 and April 2021. Each patient underwent best-corrected visual acuity (BCVA) measurement with a Snellen chart (converted to LogMAR for analysis), central subfield thickness (CST) analysis with spectral-domain optical coherence tomography (SD-OCT) and intraocular pressure (IOP) measurement along with complete ophthalmic examination at baseline and the last follow-up for evaluation of adverse events after ranizurel injection.

RESULTS

- None of the sites reported any signs of inflammation, vasculitis or any other ocular or systemic adverse effects in any of the cases. Mean BCVA at baseline was 0.48 ± 0.26 LogMAR (20/63) which improved significantly 0.26 ± 0.28 (20/40) at the last follow-up. (p = 0.001) Mean CST at baseline was 448.4 ± 122.9 μm which improved significantly to 328.3 ± 89.9 μm. (p = 0.001).

CONCLUSION

- The early real-world data from this limited series indicates that ranizurel is a safe alternative biologic for patients who were treatment-naive and in those who had undergone prior treatment with other anti-VEGF agents.

Deliver protein across bio-barriers via hexa-histidine metal assemblies for therapy: a case in corneal neovascularization model

Because of their high specificity and low side effects, protein drugs possess a substantial global market. However, the low bioavailability of protein is still a major obstacle to their expanded applications, which is expected to be answered with proper protein formulations. Taking corneal neovascularization (CNV) as an example, we demonstrated a co-assembled system of hexa-histidine and Ava (Avastin) with metal ions (HmA@Ava) could cross the cornea, the most important bio-barrier during the treatment of most diseases of the anterior segment in clinics. We found that the nanosized HmA@Ava efficiently encapsulated Ava with impressive loading capacity without destroying the bioactivity of Ava and assisted Ava penetration through the corneal barriers to effectively inhibit CNV development in an alkali burn rat model with sustained and pH-dependent Ava release. Our results suggested that the co-assembled strategy of protein and HmA is a proper formulation to protein drugs, with promising penetration ability to deliver protein across bio-barriers, which could open a path for topical administration of protein drugs for treatment of various ocular diseases and hold enormous potential for delivery of therapeutic proteins not only for ocular diseases but also for other diseases that require protein treatment.

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HmA@Ava can bring protein drug, Ava, across over the primary bio-barrier of the anterior segment ​and efficiently treat CNV.

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HmA@Ava was nanoparticles, with impressive loading capacity without destroying bioactivity of Ava ​and strong pH-dependent release.

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HmA can open a path for the treatment of eye diseases and hold huge potential to protein drugs to other diseases.

Novel Treatments for Diabetic Macular Edema and Proliferative Diabetic Retinopathy

PURPOSE OF REVIEW

Diabetic retinopathy (DR), a common cause of vision loss, is projected to increase worldwide, and is associated with significant morbidity. The current standard-of-care treatments can preserve and significantly improve vision in many patients affected by DR. However, challenges such as heavy treatment burden and refractory disease remain. The purpose of this review is to highlight and discuss investigative agents in development for the treatment of DR.

RECENT FINDINGS

There are several novel agents with unique mechanisms that may offer greater durability and efficacy compared to existing drugs. Some target new pathways, others leverage a slow-release delivery system, and some modify gene expression through a single-dose treatment. While unfavorable adverse events, such as intraocular inflammation, have been observed with longer-durability agents, many investigational products show excellent efficacy and safety profiles. The outcomes of ongoing and future trials may revolutionize the current treatment paradigm for DR.

Anti-VEGF and Other Novel Therapies for Neovascular Age-Related Macular Degeneration: An Update

Age-related macular degeneration (AMD) is a leading cause of visual impairment and blindness in older adults. The prognosis for the neovascular type of advanced AMD improved with the introduction of biological drugs with antiangiogenic properties, beginning with off-label bevacizumab, which was first used intravitreally in 2006. These drugs target newly formed vessels that grow beneath the center of the retina, causing loss of central vision, and they can help to maintain or improve vision. Repeated intravitreal injections are needed to achieve prolonged inhibition of proangiogenic cytokines, primarily vascular endothelial growth factor (VEGF). Major regulatory agencies have approved several molecules for AMD treatment, including ranibizumab, aflibercept, and brolucizumab. The development of further drugs was mainly targeted at prolonging anti-VEGF inhibition-thus reducing the frequency of injections-and expanding the biological targets of proangiogenic cytokine inhibition. Finally, biosimilars are already being marketed in some countries, allowing the containment of costs of AMD treatment, which are growing steadily in many settings because of the need for long-term treatment. This review summarizes the properties and clinical profiles of anti-VEGF biological drugs that are approved to treat neovascular AMD as well as ongoing research on molecules that may be marketed in the near future.

Recent trends in drug-delivery systems for the treatment of diabetic retinopathy and associated fibrosis

Diabetic retinopathy is a frequent microvascular complication of diabetes and a major cause of visual impairment. In advanced stages, the abnormal neovascularization can lead to fibrosis and subsequent tractional retinal detachment and blindness. The low bioavailability of the drugs at the target site imposed by the anatomic and physiologic barriers within the eye, requires long term treatments with frequent injections that often compromise patient's compliance and increase the risk of developing more complications. In recent years, much effort has been put towards the development of new drug delivery platforms aiming to enhance their permeation, to prolong their retention time at the target site and to provide a sustained release with reduced toxicity and improved efficacy. This review provides an overview of the etiology and pathophysiology of diabetic retinopathy and current treatments. It addresses the specific challenges associated to the different ocular delivery routes and provides a critical review of the most recent developments made in the drug delivery field.