Ophthalmic biosimilars and biologics-role of endotoxins

Intravitreal Anti-Vascular Endothelial Growth Factor Therapies for Retinal Disorders

Vascular endothelial growth factors (VEGFs) are key mediator of retinal and choroidal neovascularization as well as retinal vascular leakage leading to macular edema. As such, VEGF plays an important role in mediating visually significant complications associated with common retinal disorders such as diabetic retinopathy, retinal vein occlusion, and age-related macular degeneration. Various drugs that inhibit vascular endothelial growth factors (anti-VEGF therapies) have been developed to minimize vision loss associated with these disorders. These drugs are injected into the vitreous cavity in a clinic setting at regular intervals. This article provides an overview of the various anti-VEGF drugs used in ophthalmology and the common retinal conditions that benefit from this therapy.

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.

Immunogenicity With Ranibizumab Biosimilar SB11 (Byooviz) and Reference Product Lucentis and Association With Efficacy, Safety, and Pharmacokinetics: A Post Hoc Analysis of a Phase 3 Randomized Clinical Trial

Importance

SB11 and reference ranibizumab (RBZ) are monoclonal anti-vascular endothelial growth factor (VEGF)-A antibodies approved for the treatment of neovascular age-related macular degeneration (nAMD) and other retinal diseases. The association of ranibizumab immunogenicity and treatment outcomes in patients with nAMD is unclear but relevant regarding concerns about immunogenicity of anti-VEGF biological products.

Objective

To examine the association of immunogenicity to ranibizumab products (SB11 and RBZ) with efficacy, safety, and pharmacokinetics.

Design, Setting, and Participants

This was a post hoc analysis of a randomized, double-masked, parallel-group phase 3 equivalence study with participants from 75 centers in 9 countries conducted from March 14, 2018, to December 9, 2019. Included were participants 50 years or older with nAMD and active subfoveal choroidal neovascularization lesions.

Interventions

Intravitreal injection of SB11 or RBZ, 0.5 mg, every 4 weeks through week 48.

Main Outcomes and Measures

Serum antidrug antibodies (ADAs) were analyzed during the study period until week 52 to measure immunogenicity. Analyses were performed on immunogenicity (overall ADA positivity) with best-corrected visual acuity (BCVA) and central subfield thickness (CST). Adverse events associated with intraocular inflammation (IOI) and serum ranibizumab levels were compared between overall ADA-positive and ADA-negative participants.

Results

A total of 705 participants (mean [SD] age, 74.1 [8.5] years; 403 female individuals [57.2%]) were included in the study. The overall incidence of ADA-positivity was 32 of 657 (4.9%) at week 52. The least-squares mean (SE) differences between overall ADA-positive and ADA-negative participants up to week 52 for BCVA and CST, respectively, were 1.6 (2.2) letters (95% CI, -2.7 to 5.8; P = .46) and 3 (13) μm (95% CI, -23 to 29; P = .83). IOI-related events occurred in 1 of 32 overall ADA-positive participants (3.1%) and 4 of 620 overall ADA-negative participants (0.6%). Mean (SD) serum ranibizumab concentrations over time were slightly lower in overall ADA-positive participants compared with those of ADA-negative participants, with a maximum value of 1389.3 (875.4) pg/mL at week 16 vs 1665.4 (1124.0) pg/mL at week 36, respectively.

Conclusions and Relevance

Results of this post hoc analysis of an equivalence trial suggest that immunogenicity was not associated with efficacy and safety of SB11 and RBZ in participants with nAMD. With a low overall ADA incidence, no clear association was identified between overall ADA positivity and pharmacokinetics. These findings support the biosimilarity of SB11 and RBZ, with no safety concern identified for SB11 vs RBZ associated with immunogenicity.

Trial Registration

ClinicalTrials.gov Identifier: NCT03150589.

Biosimilars for Retinal Diseases: An Update

PURPOSE

To review the biosimilars of anti-vascular endothelial growth factor agents for retinal diseases and provide an update about their development.

DESIGN

Literature review.

METHODS

A comprehensive literature review was performed for scientific articles, clinical trials, and press releases for the development of biosimilars in ophthalmology.

RESULTS

To date, Razumab (Intas Pharmaceuticals Ltd, Ahmedabad, GJ, India) is the only approved biosimilar for ophthalmic use, but the landscape will rapidly change in the future with multiple biosimilar candidates, which are currently in phase 3 trials, showing promising early results.

CONCLUSION

Biosimilars hold the potential to reduce the financial burden of the highly efficacious biologic therapy in retinal pathologies. However, the off-label bevacizumab may differentiate the success of biosimilars in different geographic regions.

Inflammatory Complications of Intravitreal Anti-VEGF Injections

Intravitreal injection of anti-vascular endothelial growth factor (anti-VEGF) agents is a commonly used therapy for numerous retinal diseases. The most commonly used of these medications are bevacizumab, ranibizumab, aflibercept, and brolucizumab. However, intravitreal administration of these agents is also associated with several inflammatory and non-inflammatory adverse events. The three inflammatory adverse events are sterile intraocular inflammation, brolucizumab-associated retinal vasculitis, and post-injection endophthalmitis. This narrative review summarizes the current literature regarding these conditions, including their epidemiology, presentation, management, outcomes, and pathogenesis. The inflammatory adverse events also share a number of overlapping features, which can make them difficult to discern from one another in a clinical context. This review discusses certain distinguishing features of these conditions that may aid providers in discerning between them and establishing the correct diagnosis.

Selected Aspects of Ocular Toxicity Studies With a Focus on High-Quality Pathology Reports: A Pathology/Toxicology Consultant's Perspective

Ocular toxicity studies are the bedrock of nonclinical ocular drug and drug-device development, and there has been an evolution in experience, technologies, and challenges to address that ensures safe clinical trials and marketing authorization. The expectations of a well-designed ocular toxicity study and the generation of a coherent, integrative ocular toxicology report and subreports are high, and this article provides a pathology/toxicology consultant's perspective on achieving that goal. The first objective is to cover selected aspects of study designs for ocular toxicity studies including considerations for contract research organization selection, minipig species selection, unilateral versus bilateral dosing, and in-life parameters based on fit-for-purpose study objectives. The main objective is a focus on a high-quality ocular pathology report that includes ocular histology procedures to meet regulatory expectations and a report narrative and tables that correlate microscopic findings with key ophthalmic findings and presents a clear interpretation of test article-, vehicle-, and procedure-related ocular and extraocular findings with identification of adversity and a pathology peer review. The last objective covers considerations for a high-quality ophthalmology report, which in concert with a high-quality pathology report, will pave the way for a best quality toxicology report for an ocular toxicity study.