Anti-brolucizumab immune response as one prerequisite for rare retinal vasculitis/retinal vascular occlusion adverse events

Flare levels after intravitreal injection of brolucizumab for diabetic macular edema

PURPOSE

This study aimed to evaluate anterior flare intensity (AFI) after intravitreal injection of brolucizumab (IVBr) in patients with diabetic macular edema (DME), and to identify the factors associated with the change of AFI after IVBr.

METHODS

This prospective multicenter study was conducted at five sites in Japan for patients with DME who underwent a single IVBr. AFI and central retinal thickness (CRT) were measured using a laser flare meter and spectral-domain optical coherence tomography, respectively, at weeks 0 and 6.

RESULTS

Sixty-five patients (phakia, 37 eyes; pseudophakia, 28 eyes) were enrolled. Six weeks after IVBr, CRT and best-corrected visual acuity significantly improved (p < 0.0001). AFI (p = 0.0003) and age (p = 0.0054) were significantly higher in patients with pseudophakic eyes than those with phakic eyes. The AFI of the phakic eyes decreased after IVBr (p = 0.043). As the AFI before injection is higher (p = 0.0363) and the age is lower (p = 0.0016), the AFI decreases after IVBr. There was a significant positive correlation between the rates of change in CRT and AFI (p = 0.024).

CONCLUSION

After IVBr, AFI decreases in phakic eyes but not in pseudophakic eyes. The age, AFI and CRT before injection and changes of CRT are involved in the change in AFI after IVBr.

KESTREL and KITE Phase 3 Studies: 100-Week Results With Brolucizumab in Patients With Diabetic Macular Edema

PURPOSE

To report the 100-week outcomes from the KESTREL and KITE trials.

DESIGN

Two phase 3, double-masked, active-controlled, randomized trials.

METHODS

Patients with diabetic macular edema (DME) were randomized 1:1:1 to brolucizumab 3 mg/6 mg (BRO3/BRO6) or aflibercept 2 mg (AFL) in KESTREL (N = 566) or 1:1 to BRO6 or AFL in KITE (N = 360). BRO3/BRO6 arms received 5 loading doses every 6 weeks (q6w) followed by q12w dosing, with an option to adjust to q8w at predefined disease activity assessment visits. In KITE, at week 72, based on the disease stability assessment, treatment intervals could be extended by 4 weeks in the BRO6 arm. AFL arms received 5 monthly loading doses followed by fixed q8w dosing.

RESULTS

At week 100, change from baseline in BCVA (letters) was +8.8 for BRO6 and +10.6 for AFL in KESTREL; and +10.9 for BRO6 and +8.4 for AFL in KITE. In both studies, fewer BRO6 subjects had intraretinal fluid and/or subretinal fluid than AFL subjects. Results were achieved with 32.9% (KESTREL) and 47.5% (KITE) of BRO6 subjects maintained on q12w and q12w/q16w dosing, respectively. Intraocular inflammation rates for BRO6 vs AFL were 4.2% vs 1.1% (KESTREL) and 2.2% vs 1.7% (KITE), of which retinal vasculitis rates were 0.5% vs 0% in KESTREL, with no cases in KITE. Retinal vascular occlusion rates were 1.6% vs 0.5% (KESTREL) and 0.6% in both treatment arms in KITE.

CONCLUSIONS

Results show the long-term efficacy and durability of brolucizumab in improving visual and anatomical outcomes in DME; the overall safety profile of brolucizumab remained unchanged through year 2.

Reducing Immunogenicity by Design: Approaches to Minimize Immunogenicity of Monoclonal Antibodies

Monoclonal antibodies (mAbs) have transformed therapeutic strategies for various diseases. Their high specificity to target antigens makes them ideal therapeutic agents for certain diseases. However, a challenge to their application in clinical practice is their potential risk to induce unwanted immune response, termed immunogenicity. This challenge drives the continued efforts to deimmunize these protein therapeutics while maintaining their pharmacokinetic properties and therapeutic efficacy. Because mAbs hold a central position in therapeutic strategies against an array of diseases, the importance of conducting comprehensive immunogenicity risk assessment during the drug development process cannot be overstated. Such assessment necessitates the employment of in silico, in vitro, and in vivo strategies to evaluate the immunogenicity risk of mAbs. Understanding the intricacies of the mechanisms that drive mAb immunogenicity is crucial to improving their therapeutic efficacy and safety and developing the most effective strategies to determine and mitigate their immunogenic risk. This review highlights recent advances in immunogenicity prediction strategies, with a focus on protein engineering strategies used throughout development to reduce immunogenicity.

Factors Associated With Intraocular Inflammation in Neovascular Age-Related Macular Degeneration Patients Treated With Brolucizumab

Purpose

To identify factors associated with intraocular inflammation (IOI) in patients with neovascular age-related macular degeneration (nAMD) treated with brolucizumab.

Methods

In this prospective observational study, we collected aqueous humor samples from 96 eyes of 96 patients receiving treatment with brolucizumab; IOI subsequently developed in 19 eyes of 19 patients. To identify cytokines upregulated in eyes with subsequent development of IOI, we compared the aqueous humor cytokine levels between the IOI and non-IOI groups. We also collected plasma from 20 patients who developed IOI and 20 age- and sex-matched controls to identify differences in plasma biomarkers and the subfraction of CD4+ cells. Using stepwise variable selection and multivariate binary regression analysis, we developed an algorithm that accurately assessed the likelihood of IOI occurrence.

Results

The IOI group showed elevated aqueous humor levels of P-selectin (584 vs. 324 pg/mL, P = 0.013), TNF-α (0.89 vs. 0.60 pg/mL, P = 0.018), and IL-1α (2.0 vs. 1.4 pg/mL, P = 0.035) compared with the non-IOI group. Serum MMP-9 concentrations were higher in the IOI group than the non-IOI group (18,310 vs. 13,450 pg/mL, P = 0.029). Furthermore, the percentage of Th2 cells was significantly decreased in the IOI compared with the non-IOI group (3.1% vs. 4.2%, P = 0.013). The receiver operating characteristic curves for the optimal models showed an area under the curve ranging from 0.71 to 0.89, indicating good performance.

Conclusions

The combination of elevated concentrations of multiple aqueous humor cytokines and of serum MMP-9 and a lower number of plasma Th2 cells is associated with brolucizumab-related IOI in patients with nAMD.

Proceedings of the 14th European immunogenicity platform open symposium on immunogenicity of biopharmaceuticals

Biologics have revolutionized disease management in many therapeutic areas by addressing unmet medical needs and overcoming resistance to standard-of-care treatment in numerous patients. However, the development of unwanted immune responses directed against these drugs, humoral and/or cellular, can hinder their efficacy and have safety consequences with various degrees of severity. Health authorities ask that a thorough immunogenicity risk assessment be conducted during drug development to incorporate an appropriate monitoring and mitigation plan in clinical studies. With the rapid diversification and complexification of biologics, which today include modalities such as multi-domain antibodies, cell-based products, AAV delivery vectors, and nucleic acids, developers are faced with the challenge of establishing a risk assessment strategy sometimes in the absence of specific regulatory guidelines. The European Immunogenicity Platform (EIP) Open Symposium on Immunogenicity of Biopharmaceuticals and its one-day training course gives experts and newcomers across academia, industry, and regulatory agencies an opportunity to share experience and knowledge to overcome these challenges. Here, we report the discussions that took place at the EIP's 14th Symposium, held in April 2023. The topics covered included immunogenicity monitoring and clinical relevance, non-clinical immunogenicity risk assessment, regulatory aspects of immunogenicity assessment and reporting, and the challenges associated with new modalities, which were discussed in a dedicated session.

Gains in the current understanding of managing neovascular AMD with brolucizumab

BACKGROUND

Unresolved retinal fluid and high injection burden are major challenges for patients with neovascular age-related macular degeneration. Brolucizumab addresses these challenges by providing robust vision gains and superior fluid resolution, with the potential for longer treatment intervals. Brolucizumab has been associated with adverse events of retinal vasculitis and retinal vascular occlusion typically in the presence of intraocular inflammation (IOI). To define the incidence of the adverse events, Novartis convened an external safety review committee, which found a rate of 4.6% for definite or probable IOI, 3.3% for retinal vasculitis, and 2.1% for retinal vascular occlusion in the HAWK and HARRIER trials. Novartis also established a coalition to explore 4 areas regarding the adverse events: root cause, patient characterization, event mitigation and vigilance, and treatment protocols for the adverse events. Based on the coalition findings, a risk mitigation framework was developed. Prior to initiating treatment with brolucizumab, it is important to weigh the potential benefit against risk of adverse events and to consider patient risk factors such as prior history of IOI and/or retinal vascular occlusion. To mitigate the potential for IOI-related adverse events, it is important to conduct a thorough dilated eye examination before each injection and closely monitor patients throughout treatment. Patients should be educated on symptoms of IOI to monitor for. Brolucizumab should not be injected in the presence of active IOI. If an adverse event is identified, prompt and intensive treatment should be considered.

CONCLUSION

Progress has been made in understanding how to mitigate IOI-related adverse events following treatment with brolucizumab.

Biology and therapeutic targeting of vascular endothelial growth factor A

The formation of new blood vessels, called angiogenesis, is an essential pathophysiological process in which several families of regulators have been implicated. Among these, vascular endothelial growth factor A (VEGFA; also known as VEGF) and its two tyrosine kinase receptors, VEGFR1 and VEGFR2, represent a key signalling pathway mediating physiological angiogenesis and are also major therapeutic targets. VEGFA is a member of the gene family that includes VEGFB, VEGFC, VEGFD and placental growth factor (PLGF). Three decades after its initial isolation and cloning, VEGFA is arguably the most extensively investigated signalling system in angiogenesis. Although many mediators of angiogenesis have been identified, including members of the FGF family, angiopoietins, TGFβ and sphingosine 1-phosphate, all current FDA-approved anti-angiogenic drugs target the VEGF pathway. Anti-VEGF agents are widely used in oncology and, in combination with chemotherapy or immunotherapy, are now the standard of care in multiple malignancies. Anti-VEGF drugs have also revolutionized the treatment of neovascular eye disorders such as age-related macular degeneration and ischaemic retinal disorders. In this Review, we emphasize the molecular, structural and cellular basis of VEGFA action as well as recent findings illustrating unexpected interactions with other pathways and provocative reports on the role of VEGFA in regenerative medicine. We also discuss clinical and translational aspects of VEGFA. Given the crucial role that VEGFA plays in regulating angiogenesis in health and disease, this molecule is largely the focus of this Review.

Detection and Management of Intraocular Inflammation after Brolucizumab Treatment for Neovascular Age-Related Macular Degeneration

PURPOSE

To present interim descriptive insights from the OCTOPUS and SWIFT studies on incidence, clinical features, management, and outcomes of intraocular inflammation (IOI), vasculitis, and occlusive vasculitis with brolucizumab treatment (Beovu, Novartis) in patients with neovascular age-related macular degeneration (nAMD) who were anti-VEGF naive or pretreated with anti-VEGFs (ranibizumab or aflibercept).

DESIGN

OCTOPUS (NCT04239027) and SWIFT (NCT04264819) studies are prospective phase IIIb single-arm, open-label, multicenter studies assessing brolucizumab.

SUBJECTS

Anti-VEGF naive (OCTOPUS) and pretreated (SWIFT) patients with nAMD.

METHODS

Interim prespecified analysis on the efficacy end point provided an opportunity to analyze IOI-related safety. Reports of IOI-related adverse events (AEs) were reviewed, and AE images and clinical features and outcomes of each case were analyzed by a review committee.

RESULTS

Of 505 brolucizumab-treated eyes/patients with median brolucizumab treatment of 8.8 months, 53 eyes demonstrated at least 1 IOI-related AE. The incidence of overall IOI-related AEs was 10.5%; among these events, the incidence was 7.1% for IOI only without retinal involvement and 3.4% for IOI with retinal involvement (2.0% with vasculitis, 1.4% with vascular occlusion with or without vasculitis). Incidence was similar in naive and pretreated patients. Before the onset of the first IOI-related AE, eyes received a median of 2 brolucizumab injections; 81.1% of IOI-related AEs occurred during the loading phase (median, 25.0 days from the last brolucizumab injection). At AE onset, most frequently reported symptoms were floaters (52.8%) and blurred or decreased vision (37.8%). Of the 86.8% of AEs that were treated, most were treated with topical corticosteroids (75.5%), 28.3% by systemic corticosteroids, and 26.8% by intraocular corticosteroids. No severe vision loss was reported for the 7 nontreated AEs. Overall, the median best-corrected visual acuity (BCVA) change at IOI-related AEs resolution from baseline was 1 letter (range, -74 to +32 letters), and 2 patients with occlusive vasculitis had BCVA loss ≥ 15 letters due to IOI-related AEs. All eyes permanently discontinued brolucizumab after the first IOI-related AE.

CONCLUSIONS

This analysis highlights the need for monitoring and education of patients to report any signs of IOI-related events immediately when being treated with brolucizumab. IOI should be treated promptly and intensely with corticosteroids.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Twenty Years of Anti-Vascular Endothelial Growth Factor Therapeutics in Neovascular Age-Related Macular Degeneration Treatment

Neovascular age-related macular degeneration (nAMD) is the primary disastrous retinal disease that leads to blindness in the elderly population. In the early 2000s, nAMD resulted in irreversible vision loss and blindness with no available treatment options. However, there have been breakthrough advances in the drug development of anti-angiogenic biological agents over the last two decades. The primary target molecule for treating nAMD is the vascular endothelial growth factor (VEGF), and there are currently several anti-VEGF drugs such as bevacizumab, ranibizumab, and aflibercept, which have made nAMD more manageable than before, thus preventing vision loss. Nevertheless, it should be noted that these anti-VEGF drugs for nAMD treatment are not effective in more than half of the patients, and even those who initially gain visual improvements lose their vision over time, along with potential deterioration in the geography of atrophy. As a result, there have been continuous endeavors to improve anti-VEGF agents through better efficacy, fewer doses, expanded intervals, and additional targets. This review describes past and current anti-VEGF therapeutics used to treat nAMD and outlines future directions to improve the effectiveness and safety of anti-VEGF agents.

2022 White Paper on Recent Issues in Bioanalysis: FDA Draft Guidance on Immunogenicity Information in Prescription Drug Labeling, LNP & Viral Vectors Therapeutics/Vaccines Immunogenicity, Prolongation Effect, ADA Affinity, Risk-based Approaches, NGS, qPCR, ddPCR Assays (Part 3 - Recommendations on Gene Therapy, Cell Therapy, Vaccines Immunogenicity & Technologies; Immunogenicity & Risk Assessment of Biotherapeutics and Novel Modalities; NAb Assays Integrated Approach)

The 2022 16th Workshop on Recent Issues in Bioanalysis (WRIB) took place in Atlanta, GA, USA on September 26-30, 2022. Over 1000 professionals representing pharma/biotech companies, CROs, and multiple regulatory agencies convened to actively discuss the most current topics of interest in bioanalysis. The 16th WRIB included 3 Main Workshops and 7 Specialized Workshops that together spanned 1 week in order to allow exhaustive and thorough coverage of all major issues in bioanalysis, biomarkers, immunogenicity, gene therapy, cell therapy and vaccines. Moreover, in-depth workshops on ICH M10 BMV final guideline (focused on this guideline training, interpretation, adoption and transition); mass spectrometry innovation (focused on novel technologies, novel modalities, and novel challenges); and flow cytometry bioanalysis (rising of the 3rd most common/important technology in bioanalytical labs) were the special features of the 16th edition. As in previous years, WRIB continued to gather a wide diversity of international, industry opinion leaders and regulatory authority experts working on both small and large molecules as well as gene, cell therapies and vaccines to facilitate sharing and discussions focused on improving quality, increasing regulatory compliance, and achieving scientific excellence on bioanalytical issues. This 2022 White Paper encompasses recommendations emerging from the extensive discussions held during the workshop and is aimed to provide the bioanalytical community with key information and practical solutions on topics and issues addressed, in an effort to enable advances in scientific excellence, improved quality and better regulatory compliance. Due to its length, the 2022 edition of this comprehensive White Paper has been divided into three parts for editorial reasons. This publication (Part 3) covers the recommendations on Gene Therapy, Cell therapy, Vaccines and Biotherapeutics Immunogenicity. Part 1 (Mass Spectrometry and ICH M10) and Part 2 (LBA, Biomarkers/CDx and Cytometry) are published in volume 15 of Bioanalysis, issues 16 and 15 (2023), respectively.

Inflammatory Processes in Alzheimer's Disease-Pathomechanism, Diagnosis and Treatment: A Review

Alzheimer's disease is one of the most commonly diagnosed cases of senile dementia in the world. It is an incurable process, most often leading to death. This disease is multifactorial, and one factor of this is inflammation. Numerous mediators secreted by inflammatory cells can cause neuronal degeneration. Neuritis may coexist with other mechanisms of Alzheimer's disease, contributing to disease progression, and may also directly underlie AD. Although much has been established about the inflammatory processes in the pathogenesis of AD, many aspects remain unexplained. The work is devoted in particular to the pathomechanism of inflammation and its role in diagnosis and treatment. An in-depth and detailed understanding of the pathomechanism of neuroinflammation in Alzheimer's disease may help in the development of diagnostic methods for early diagnosis and may contribute to the development of new therapeutic strategies for the disease.

A root cause analysis to identify the mechanistic drivers of immunogenicity against the anti-VEGF biotherapeutic brolucizumab

Immunogenicity against intravitreally administered brolucizumab has been previously described and associated with cases of severe intraocular inflammation, including retinal vasculitis/retinal vascular occlusion (RV/RO). The presence of antidrug antibodies (ADAs) in these patients led to the initial hypothesis that immune complexes could be key mediators. Although the formation of ADAs and immune complexes may be a prerequisite, other factors likely contribute to some patients having RV/RO, whereas the vast majority do not. To identify and characterize the mechanistic drivers underlying the immunogenicity of brolucizumab and the consequence of subsequent ADA-induced immune complex formation, a translational approach was performed to bridge physicochemical characterization, structural modeling, sequence analysis, immunological assays, and a quantitative systems pharmacology model that mimics physiological conditions within the eye. This approach revealed that multiple factors contributed to the increased immunogenic potential of brolucizumab, including a linear epitope shared with bacteria, non-natural surfaces due to the single-chain variable fragment format, and non-native drug species that may form over prolonged time in the eye. Consideration of intraocular drug pharmacology and disease state in a quantitative systems pharmacology model suggested that immune complexes could form at immunologically relevant concentrations modulated by dose intensity. Assays using circulating immune cells from treated patients or treatment-naïve healthy volunteers revealed the capacity of immune complexes to trigger cellular responses such as enhanced antigen presentation, platelet aggregation, endothelial cell activation, and cytokine release. Together, these studies informed a mechanistic understanding of the clinically observed immunogenicity of brolucizumab and associated cases of RV/RO.