Pharmacokinetics, pharmacodynamics and pre-clinical characteristics of ophthalmic drugs that bind VEGF

Comparison of the efficacy and safety of SCD411 and reference aflibercept in patients with neovascular age-related macular degeneration

To compare the efficacy and safety of the proposed aflibercept biosimilar SCD411 and reference aflibercept in patients with neovascular age-related macular degeneration, this randomized, double-masked, parallel-group, multicenter study was conducted in 14 countries from 13 August 2020 to 8 September 2022. Patients with neovascular age-related macular degeneration. With subfoveal, juxtafoveal, or extrafoveal choroidal neovascularization were aged 50 years or older. Intravitreal injection of SCD411 or aflibercept (2.0 mg) were administered every 4 weeks for the first three injections and every 8 weeks until week 48. The primary efficacy endpoint was the change in best-corrected visual acuity from baseline to week 8 with an adjusted equivalence margin of ± 3.0 letters. Patients were randomly assigned to receive either SCD411 (n = 288) or reference aflibercept (n = 288). A total of 566 participants (98.3%) completed week 8 of the study. The least-squares mean difference of change in best-corrected visual acuity from baseline to week 8 (SCD411-aflibercept) was - 0.4 letters (90% confidence interval =  - 1.6 to 0.9). The incidence of ocular (69 of 287 [24.0%] vs. 71 of 286 [24.8%]) and serious ocular (5 of 287 [1.7%] vs. 3 of 286 [1.0%]) treatment-emergent adverse effects were similar between the SCD411 and aflibercept groups. Immunogenicity analysis revealed a low incidence of neutralizing antibody formation in both groups. In conclusion, SCD411 has equivalent efficacy compared with reference aflibercept in patients with neovascular age-related macular degeneration and has a comparable safety profile. The results support the potential use of SCD411 for the treatment of neovascular age-related macular degeneration.

The role of mitochondrial genes on nuclear gene expression in neovascular age related macular degeneration: analysis of nuclear VEGF gene expression after ranibizumab treatment in cytoplasmic hybrid retinal pigment epithelial cell lines correlated with clinical evolution

PURPOSE

The present study tests the hypothesis that mitochondrial genes have retrograde signaling capacity that influences the expression of nuclear genes related to angiogenesis pathways. Cytoplasmic hybrid (cybrid) in vitro cell lines with patient specific mitochondria inserted into an immortalized retinal pigment epithelial cell line (ARPE-19) were used to test this hypothesis. This type of analysis can provide important information to identify the optimal regimen of anti-VEGF treatment, personalizing age-related macular degeneration (AMD) therapies.

METHODS

Mitochondria deficient ARPE-19 cells (Rho0) were fused with AMD donor's platelets to create individual cybrid cell lines containing mitochondria from patients with phenotypic AMD disease and nuclear DNA from the immortalized RPE cell line. The cybrids were treated with Ranibizumab (Lucentis, Genentech, San Francisco, CA), at 4 different concentrations for 24 h, and subsequently the levels of reactive oxygen species (ROS), gene expression for VEGF-A, hypoxia-inducible factor 1-alpha (HIF1-a) and manganese superoxide dismutase (SOD2) were measured. The clinical evolution of the two AMD-donors were correlated with the molecular findings found in their 'personalized' cybrids.

RESULTS

Cybrids from Patient-01 showed down-regulation of gene expression of VEGF-A and HIF-1a at both 1X and 4X Ranibizumab concentrations. Patient-01 AMD cybrid cultures had an increase in the ROS levels at 1X (P = 0.0317), no changes at 2X (P = 0.8350) and a decrease at 4X (P = 0.0015) and 10X (P = 0.0011) of Ranibizumab. Clinically, Patient-01 responded to anti-VEGF therapy but eventually developed geographic atrophy. Patient-02 cybrids demonstrated up-regulation of gene expression of VEGF-A and HIF-1a at Ranibizumab 1X and 4X concentrations. There was decreased ROS levels with Ranibizumab 1X (P = 0.1606), 2X (P = 0.0388), 4X (P = 0.0010) and 10X (P =  < 0.0001). Clinically, Patient-02 presented with a neovascular lesion associated with a prominent production of intraretinal fluid in clinical follow-up requiring regular and repeated intravitreal injections of Ranibizumab with recurrent subretinal fluid.

CONCLUSIONS

Our cybrid model has the potential to help personalize the treatment regimen with anti-VEGF drugs in patients with neovascular AMD. Further investigation is needed to better understand the role that the mitochondria play in the cellular response to anti-VEGF drugs. Future studies that focus on this model have the potential to help personalize anti-VEGF treatment.

Biomaterial Drug Delivery Systems for Prominent Ocular Diseases

Ocular diseases, such as age-related macular degeneration (AMD) and glaucoma, have had a profound impact on millions of patients. In the past couple of decades, these diseases have been treated using conventional techniques but have also presented certain challenges and limitations that affect patient experience and outcomes. To address this, biomaterials have been used for ocular drug delivery, and a wide range of systems have been developed. This review will discuss some of the major classes and examples of biomaterials used for the treatment of prominent ocular diseases, including ocular implants (biodegradable and non-biodegradable), nanocarriers (hydrogels, liposomes, nanomicelles, DNA-inspired nanoparticles, and dendrimers), microneedles, and drug-loaded contact lenses. We will also discuss the advantages of these biomaterials over conventional approaches with support from the results of clinical trials that demonstrate their efficacy.

Combined phacoemulsification surgery and intravitreal triamcinolone injection versus stand-alone surgery in patients with type 2 diabetes: a prospective randomized trial

Background

We would assess the efficacy of intravitreal injection of triamcinolone acetonide IVTA combined with standard phacoemulsification on the central subfield macular thickness (CSMT), the progression of diabetic retinopathy (DR), and the corrected distant visual acuity (CDVA) in type 2 diabetic patients.

Methods

In this prospective single-blinded randomized clinical trial we recruited patients with type 2 diabetes who were eligible for cataract surgery. The patients were randomly assigned to two groups. The case group received an intravitreal IVTA at the end of phacoemulsification, and the control group had routine surgery. CSMT, progression of DR, CDVA, IOP, and adverse events including endophthalmitis were compared between the groups preoperatively and at 1, 3, and 6 months postoperatively.

Results

Among a total of 66 patients that were treated within the study period, 50 patients were included in the final analysis. The case group comprised 21 eyes, and the control group included 29 eyes. Regression models and corrected ANOVA test for repeated measures showed a significant reduction in CSMT at 3 and 6 months postoperatively, which was most significant when the preoperative CSMT was ≥300 μm, with a cut-off value of 347.3 μm in the case group (p < 0.000). DR progression was halted in the case group at 6 months with 52.38% of patients having their DR classified as moderate (P = 0.012). CDVA was significantly improved from baseline 6/60 (logMAR 1.0) pre-op to 6/6 (logMAR 0.00) at 6 months post-op in the case group, and from baseline 6/120 (logMAR 1.3) pre-op to 6/12 (logMAR 0.3) at 6 months post-op in the control group. The gain in visual acuity was significantly higher in the case group at all study points (p < 0.001). No significant rise in IOP was observed at any study point in both groups (p = 0.23 > 0.05). No endophthalmitis was recorded.

Conclusions

Diabetic patients benefit significantly from cataract surgery. This study supports IVTA injection at the end of phacoemulsification in diabetic patients. Triamcinolone is an affordable (which is of particular importance in low-income countries as per our setting), and relatively safe “phaco-enhancer”.

Trial registration

NCT05413330. Initial release 10/06/2022. Unique Protocol ID: UDMS-Opthal-01-2022.

Submacular Hemorrhage Following Aflibercept Intravitreal Injection: A Report of Two Cases

Anti-vascular endothelial growth factor (anti-VEGF) injections are the most effective treatment for exudative age-related macular degeneration (AMD). However, both bevacizumab and ranibizumab have been reported to cause submacular hemorrhage (SMH) in the treatment of exudative AMD. Aflibercept has also been reported to cause SMH but only in the treatment of polypoidal choroidal vasculopathy and not exudative AMD.

This case series presents two patients with exudative AMD who developed SMH after treatment with aflibercept injections. The first patient is an 84-year-old female with exudative AMD in both eyes who presented with SMH four days after an aflibercept injection in her right eye. The second patient is a 77-year-old female who presented with exudative AMD in her left eye and SMH one month following an aflibercept injection. This case series shows that SMH in patients treated for exudative AMD is a rare yet possible complication of aflibercept injection that requires further research to establish its incidence and risk factors.

Quantitative pharmacokinetic analyses of anterior and posterior elimination routes of intravitreal anti-VEGF macromolecules using published human and rabbit data

The purpose of this study was to evaluate the contribution of the anterior elimination route for four anti-vascular endothelial growth factor (anti-VEGF) macromolecules (aflibercept, bevacizumab, pegaptanib and ranibizumab) after intravitreal injection using published human and rabbit data and three previously described pharmacokinetic (PK) modeling methods. A PubMed search was used to identify published studies with concentration-time data. The data were utilized only if the intravitreally injected drugs were used as plain solutions and several criteria for a well-performed PK study were fulfilled. The three methods to analyze rabbit data were (1) the equation for vitreal elimination half-life based molecular size assuming anterior elimination, (2) Maurice equation and plot for the ratio of aqueous humor (AH) to vitreal concentration assuming anterior elimination, and (3) the equation for amount of macromolecule eliminated anteriorly based on the area under the curve in AH. The first and third methods were used for human data. In the second and third methods, AH flow rate is a key model parameter, and it was varied between 2 and 3 μl/min. The methods were applied to data from 9 rabbit studies (1 for aflibercept, 5 for bevacizumab, and 3 for ranibizumab) and 5 human studies (1 for aflibercept, 3 for bevacizumab, and 1 for ranibizumab). Experimental half-lives of anti-VEGF macromolecules in both vitreous and aqueous humor were close to those calculated with the equations for vitreal elimination half-life in humans and rabbits. Rabbit data analyzed with Maurice plot indicated that the contribution of anterior elimination was usually at least 75%. In most human and rabbit studies, the calculated percentage of anterior elimination was at least 51%. Variability between studies was extensive for bevacizumab and ranibizumab. The results suggest that the anterior elimination route dominates after intravitreal injection of anti-VEGF macromolecules. However, the clinical data are sparse and variability is extensive, the latter emphasizing the need of proper experimental design.

Anti-VEGF Drugs Dynamics: Relevance for Clinical Practice

Background: A drug and disease assessment model was used to evaluate the impact of different treatment regimens on intravitreal ranibizumab, bevacizumab, aflibercept, and brolucizumab concentrations and the proportion of free vascular endothelial growth factor (VEGF) to total VEGF. Methods: A time-dependent mathematical model using Wolfram Mathematica software was used. The pharmacokinetic and pharmacodynamic data for anti-VEGFs were obtained from published reports. The model simulated drug concentration after single and multiple doses of ranibizumab, bevacizumab, aflibercept, and brolucizumab, and it extrapolated time-dependent intraocular free VEGF proportion values. Various fixed treatment regimens (q4, q8, q10, q12) were simulated and evaluated as candidates for clinical utilization. Results: Our mathematical model shows good correlation between intraocular VEGF proportion values and clinical data. Simulations suggest that each anti-VEGF agent would allow for distinct treatment intervals to keep the proportion of free VEGF under threshold levels. Regimens scheduling q8 ranibizumab, q8 bevacizumab, q12 aflibercept, and q10 brolucizumab administration permit to maintain the proportion of unbound VEGF below 0.001%. Conclusions: Fixed q8 ranibizumab, q8 bevacizumab, q12 aflibercept, or q10 brolucizumab regimens may produce adequate intraocular VEGF inhibition.

Non-human primates in the PKPD evaluation of biologics: Needs and options to reduce, refine, and replace. A BioSafe White Paper

Monoclonal antibodies (mAbs) deliver great benefits to patients with chronic and/or severe diseases thanks to their strong specificity to the therapeutic target. As a result of this specificity, non-human primates (NHP) are often the only preclinical species in which therapeutic antibodies cross-react with the target. Here, we highlight the value and limitations that NHP studies bring to the design of safe and efficient early clinical trials. Indeed, data generated in NHPs are integrated with in vitro information to predict the concentration/effect relationship in human, and therefore the doses to be tested in first-in-human trials. The similarities and differences in the systems defining the pharmacokinetics and pharmacodynamics (PKPD) of mAbs in NHP and human define the nature and the potential of the preclinical investigations performed in NHPs. Examples have been collated where the use of NHP was either pivotal to the design of the first-in-human trial or, inversely, led to the termination of a project prior to clinical development. The potential impact of immunogenicity on the results generated in NHPs is discussed. Strategies to optimize the use of NHPs for PKPD purposes include the addition of PD endpoints in safety assessment studies and the potential re-use of NHPs after non-terminal studies or cassette dosing several therapeutic agents of interest. Efforts are also made to reduce the use of NHPs in the industry through the use of in vitro systems, alternative in vivo models, and in silico approaches. In the case of prediction of ocular PK, the body of evidence gathered over the last two decades renders the use of NHPs obsolete. Expert perspectives, advantages, and pitfalls with these alternative approaches are shared in this review.

Intravitreal aflibercept following treat and extend protocol versus fixed protocol for treatment of neovascular age-related macular degeneration

Background

To assess the morphological and functional outcome of intravitreal aflibercept following the treat and extend protocol compared to the fixed protocol for treatment of eyes with neovascular age-related macular degeneration.

Methods

This retrospective study included 126 eyes of 113 patients with primary onset neovascular age-related macular degeneration who were followed for 12 months. All eyes were treated with 2 mg/0.05 mL aflibercept. All eyes received an upload with three monthly aflibercept injections. We subsequently studied two groups of eyes. For group 1, 54 eyes were treated following the treat and extend protocol. For group 2, 72 eyes were treated following the fixed protocol (fixed 2-monthly interval). Main outcome measures included: best corrected visual acuity (BCVA), central macular thickness (CMT) and number of injections.

Results

BCVA (logMAR) in group 1 vs group 2 was (0.61 ± 0.3 vs 0.72 ± 0.3, p = 0.09) before treatment and (0.48 ± 0.3 vs 0.51 ± 0.3, p = 0.6) after one year of treatment. CMT in group 1 vs group 2 was (371 ± 101 μm vs 393 ± 116 μm, p = 0.5) before treatment and (284 ± 60 μm vs 290 ± 67 μm, p = 0.1) after one year of treatment. Number of injections/eye in group 1 vs group 2 was (8.5 ± 2.2 vs 7.0 ± 0, p < 0.001).

Conclusions

Significant differences regarding BCVA and central macular thickness were not found between both treatment protocols during the first year of treatment using aflibercept. However, a significantly higher number of injections was needed for eyes in the treat and extend group during the first year of treatment. This might suggest that aflibercept should better not be extended past an 8 weeks interval during the first year of treatment.

Study registration

This study was approved by the Ethics Committee of the Medical Association of Saarland, Germany (Nr. 123/20, Date: 16.06.2020). All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. This article does not contain any studies with animals performed by any of the authors.

Clinical efficacy of aflibercept treatment in patients with ranibizumab-resistant neovascular age-related macular degeneration

THE AIMwas to evaluate clinical efficacy of aflibercept treatment in patients with ranibizumab-resistant neovascular age-related macular degeneration. MATERIALS AND METHODS.13 patients (13 eyes) after intravitreal ranibizumab therapy for 1 year (from 6 to 8 injections with an interval of 1.5 to 2 months). However, in all patients, there was a recurrence of the exudative activity of the process.Aflibercept treatment method consisted of 3 monthly loading intravitreal injections with follow-up period of 4 months. RESULTS.One month after 1st aflibercept injection among all patients, the average index of best-corrected visual acuity (BCVA) increased to 0.410.02 and the central retinal thickness (CRT) index decreased to 30714.5 m versus the initial CRT value 43164 m. After the 3rd aflibercept injection, the CRT index was the lowest and amounted to 189.513.0 m, which was accompanied BCVA increase to 0.420.03 versus 0.290.05 as the initial value. According to the optical coherence tomography data, after loading phase, good anatomical effect was observed with significant edema reduction, complete resorption of fluid in the subretinal space, and decrease of the pigment epithelial detachments height. CONCLUSION.Evaluating the results of our study, we found that the use of angiogenesis inhibitor aflibercept made it possible to suppress the signs of activity of choroidal neovascularization and to obtain additional improvement of visual functions in patients with neovascular age-related macular degeneration, when the therapeutic effect from the early ranibizumab therapy was insufficient or completely absent.

Review of the management of sight-threatening diabetic retinopathy during pregnancy

Diabetes mellitus (DM) is a noncommunicable disease reaching epidemic proportions around the world. It affects younger individuals, including women of childbearing age. Diabetes can cause diabetic retinopathy (DR), which is potentially sight threatening when severe nonproliferative DR (NPDR), proliferative DR (PDR), or sight-threatening diabetic macular oedema (STDME) develops. Pregnancy is an independent risk factor for the progression of DR. Baseline DR at the onset of pregnancy is an important indicator of progression, with up to 10% of women with baseline NPDR progressing to PDR. Progression to sight-threatening DR (STDR) during pregnancy causes distress to the patient and often necessitates ocular treatment, which may have a systemic effect. Management includes prepregnancy counselling and, when possible, conventional treatment prior to pregnancy. During pregnancy, closer follow-up is required for those with a long duration of DM, poor baseline control of blood sugar and blood pressure, and worse DR, as these are risk factors for progression to STDR. Conventional treatment with anti-vascular endothelial growth factor agents for STDME can potentially lead to foetal loss. Treatment with laser photocoagulation may be preferred, and surgery under general anaesthesia should be avoided. This review provides a management plan for STDR from the perspective of practising ophthalmologists. A review of strategies for maintaining the eyesight of diabetic women with STDR with emphasis on prepregnancy counselling and planning, monitoring and safe treatment during pregnancy, and management of complications is presented.

Nonexudative morphologic changes of neovascularization on optical coherence tomography angiography as predictive factors for exudative recurrence in age-related macular degeneration

PURPOSE

To evaluate morphologic changes of choroidal neovascularization (CNV) on optical coherence tomography angiography (OCTA) during the nonexudative period and to correlate the features and timing of recurrence in neovascular age-related macular degeneration. (AMD).

METHODS

Two hundred thirty-eight eyes with type 1 CNV were retrospectively reviewed. For cases with exudative recurrence, OCTA images were tracked for analysis between the recurrences. Qualitative parameters of morphologic changes of CNV on OCTA, including tiny branching vessels, anastomotic loops, peripheral vascular arcade, and perilesional halo, were correlated with the features of exudative recurrence.

RESULTS

Exudative recurrence was identified in 163 cases, and among them, nonexudative morphological changes in CNV were identified using OCTA in 45 cases. For the cases with nonexudative changes on OCTA, exudative recurrence eventually developed within 0.5-3.5 months (mean, 2.3 ± 2.0 months) after identifying morphologic changes OCTA. The following changes in CNV were revealed on OCTA: tiny branching vessels in 53.3% (24/45) of cases, anastomotic loops in 40.0% (18/45), peripheral vascular arcades in 44.4% (20/45), and perilesional halo in 35.6% (16/45). Among the morphologic parameters, development of tiny branching vessels was significantly associated with early exudative recurrence (1.5 ± 1.2 months, p = 0.019), higher incidence of intraretinal fluid (IRF) (p = 0.016), and subretinal or subretinal pigment epithelial hemorrhage (p = 0.023) at recurrence, compared with other morphologic changes.

CONCLUSION

Development of tiny branching vessels of CNV on OCTA during the nonexudative period was associated with early exudative recurrence, including IRF or hemorrhage. Identifying the nonexudative changes of CNV on OCTA might predict exudative recurrence and provide additional parameters for monitoring neovascular AMD.

Aflibercept clearance through the drainage system in a rat model

Background

As intravitreal anti-VEGF injections became the mainstay of treatment for many retinal diseases, the cause of a secondary sustained elevated intraocular pressure is still unclear. The aim of our study was to study the clearance of Aflibercept from the anterior chamber angle, in a rat model, to test if an aggregation exists.

Methods

Choroidal neovascular lesions (CNV) were induced in the right eye of 12 brown Norway rats, using indirect laser ophthalmoscope. Intravitreal Aflibercept injection (0.12 mg/3 µl) was performed 3 days after CNV induction. Rats were euthanized at predetermine time intervals of 3, 6, 24 and 48 h post injection, with immediate enucleation for histological analysis with H&E and immunofluorescence staining. Aflibercept molecules were stained with red fluorescence thanks to the formation of the immune complex Aflibercept-Rabbit anti human IgG-Anti rabbit antibodies-Cy3.

Results

Immediately after the injection, a strong fluorescence signal was detected, indicating the presence of Aflibercept in the iridocorneal angle. At 3- and 6-h interval a strong signal of Aflibercept was still seen. Six hours post injection, the signal was highly concentrated in Schlemm’s canal. In the 2 eyes harvested 24 h post Aflibercept injection, red fluorescence signal intensity was decreased in one eye, occupying mainly intra scleral venous plexuses, and absent in the other eye. At 48 h there was no fluorescence signal, confirming complete clearance of Aflibercept.

Conclusions

In our rat model, a complete clearance of Aflibercept from the anterior chamber angle, was seen 48 h after the injection. This finding refutes the theory of possible connection between IOP elevation and mechanical obstruction. Evacuation time of Aflibercept through the angle is of the same magnitude as that of Bevacizumab in the same rat model.

Comparison of Intravitreal Bevacizumab and Aflibercept Injections for Central Serous Chorioretinopathy

Purpose: We examined differences in the treatment effects of intravitreal bevacizumab injections and intravitreal aflibercept injections in patients with central serous chorioretinopathy. Methods: This retrospective analysis included 51 eyes of 49 patients who received intravitreal anti-vascular endothelial growth factor agent injections after initial diagnosis with central serous chorioretinopathy. The patients were divided into two groups: one received an intravitreal bevacizumab injection, and another one received an intravitreal aflibercept injection. Patients with no reaction to treatment or a worsened condition, received repeat treatment with the same therapy. After treatment, patients were monitored for >3 months. Data were collected regarding best- corrected visual acuity (BCVA), subfoveal choroidal thickness, injection number, and treatment duration. Results: Both intravitreal bevacizumab injections and intravitreal aflibercept injections led to significant differences in BCVA (p < 0.0001, p = 0.001) and subfoveal choroidal thickness (p < 0.0001, p = 0.011), compared between before and after treatment. However, no differences between groups were observed in mean change of BCVA or subfoveal choroidal thickness. In addition, there were no differences between groups in injection number and treatment duration. Conclusions: In patients with central serous chorioretinopathy, both intravitreal bevacizumab injections and intravitreal aflibercept injections are effective treatment methods. There were no differences between the two medicines in terms of functional and anatomical recovery, or the injection number and treatment duration.

Visual acuity outcomes and anti-VEGF therapy intensity in macular oedema due to retinal vein occlusion: a real-world analysis of 15 613 patient eyes

Background/Aims

To assess visual acuity (VA) outcomes and antivascular endothelial growth factor (anti-VEGF) therapy intensity in retinal vein occlusion (RVO)-related macular oedema (ME).

Methods

A retrospective study was completed in treatment-naïve patients with RVO-related ME from 2013 to 2019, using the Vestrum Health Retina Database.

Results

Mean baseline age was 72.4 years and 54% were women. In 6 months, in 8876 eyes with branch retinal vein occlusion (BRVO)-related ME, after a mean of 4.5 anti-VEGF injections, VA increased by 9.4 letters (95% confidence interval (CI) for change in VA +8.94 to +9.78, p<0.001) from a baseline of 55.1 letters. In 6737 eyes with central retinal vein occlusion (CRVO)-related ME, after a mean of 4.6 anti-VEGF injections over 6 months, VA improved by 9.2 letters (95% CI +8.50 to +9.87, p<0.001) from a baseline of 37.2 letters. In 1 year, VA gain was similar (BRVO: 7.4 injections, +8.1 letters, 95% CI +7.55 to +8.57, p<0.001; CRVO: 7.6 injections, +7.1 letters, 95% CI +6.31 to +7.95, p<0.001). In 6 months and 1 year, mean letters gain increased with number of anti-VEGF injections. Patient eyes with baseline VA of 20/40 or better tended to lose VA in 1 year.

Conclusion

Mean change in VA correlates with treatment intensity, but patients with better VA at presentation are susceptible to vision loss, reflecting a ceiling effect. Assessed with the same database, VA gains compare favourably with 1-year VA gains in neovascular age-related macular degeneration and diabetic ME, but exhibit a larger gap when compared with corresponding randomised controlled trials.

Piceatannol, a Natural Analog of Resveratrol, Exerts Anti-angiogenic Efficiencies by Blockage of Vascular Endothelial Growth Factor Binding to Its Receptor

Piceatannol is also named as trans-3,4,3′,5′-tetrahydroxy-stilbene, which is a natural analog of resveratrol and a polyphenol existing in red wine, grape and sugar cane. Piceatannol has been proved to possess activities of immunomodulatory, anti-inflammatory, antiproliferative and anticancer. However, the effect of piceatannol on VEGF-mediated angiogenesis is not known. Here, the inhibitory effects of piceatannol on VEGF-induced angiogenesis were tested both in vitro and in vivo models of angiogenesis. In human umbilical vein endothelial cells (HUVECs), piceatannol markedly reduced the VEGF-induced cell proliferation, migration, invasion, as well as tube formation without affecting cell viability. Furthermore, piceatannol significantly inhibited the formation of subintestinal vessel in zebrafish embryos in vivo. In addition, we identified the underlying mechanism of piceatannol in triggering the anti-angiogenic functions. Piceatannol was proposed to bind with VEGF, thus attenuating VEGF in activating VEGF receptor and blocking VEGF-mediated downstream signaling, including expressions of phosphorylated eNOS, Erk and Akt. Furthermore, piceatannol visibly suppressed ROS formation, as triggered by VEGF. Moreover, we further determined the outcome of piceatannol binding to VEGF in cancer cells: piceatannol significantly suppressed VEGF-induced colon cancer proliferation and migration. Thus, these lines of evidence supported the conclusion that piceatannol could down regulate the VEGF-mediated angiogenic functions with no cytotoxicity via decreasing the amount of VEGF binding to its receptors, thus affecting the related downstream signaling. Piceatannol may be developed into therapeutic agents or health products to reduce the high incidence of angiogenesis-related diseases.

Les œdèmes maculaires

L’œdème maculaire est une augmentation de volume de la macula, zone centrale de la rétine, responsable de l’acuité visuelle. Des symptômes visuels handicapent la vie de millions de patients atteints d’œdème maculaire secondaire à une maladie chronique et parfois aiguë de la rétine. Les protéines qui neutralisent la voie du facteur de croissance de l’endothélium vasculaire (VEGF) ou les glucocorticoïdes, au prix d’injections intraoculaires répétées pendant des années, limitent les symptômes visuels. Mieux comprendre pourquoi et comment l’œdème se forme et comment les molécules thérapeutiques exercent un effet anti-œdémateux permettra de mieux prévenir la survenue de cette complication rétinienne handicapante et cécitante.

Abicipar pegol: an investigational anti-VEGF agent for the treatment of wet age-related macular degeneration

INTRODUCTION

Several approaches have been investigated for the management of wet age-related macular degeneration (w-AMD); however, the first-line treatment option for w-AMD currently constitutes anti-VEGF agents. Abicipar pegol is a designed ankyrin repeat protein (DARPin), a novel, promising anti-VEGF agent for the treatment of w-AMD and is reviewed in this article.

AREAS COVERED

We discuss the pharmacokinetic, pharmacodynamic, clinical, and tolerability profile revealed by phase II REACH, CYPRESS, and BAMBOO and phase III CEDAR and SEQUOIA Trials. These two latter phase III trials revealed the non-inferiority of abicipar pegol administered with a bimonthly and quarterly regimen when compared with monthly ranibizumab.

EXPERT OPINION

Abicipar pegol has been proven to be an emerging, promising anti-VEGF agent in the management of w-AMD. The possibility of adopting a quarterly regimen would allow a decrease in treatment burden and improve patient compliance; however, further larger-scale studies should better characterize abicipar pegol clinical efficacy over longer follow-up periods.

One-year real-life results on effect of intravitreal aflibercept in patients with diabetic macular oedema switched from ranibizumab

PURPOSE

To assess visual and optical coherence tomography-derived anatomical outcomes of treatment with intravitreal aflibercept (Eylea®) for diabetic macular oedema in patients switched from intravitreal ranibizumab (Lucentis®).

DESIGN

Retrospective, cohort study.

PARTICIPANTS

Ninety eyes (of 67 patients) receiving intravitreal anti-vascular endothelial growth factor therapy were included.

METHODS

This is a retrospective, real-life, cohort study. Each patient had visual acuity measurements and optical coherence tomography scans performed at baseline and 12 months after the first injection of aflibercept was given.

MAIN OUTCOME MEASURES

We measured visual acuities in Early Treatment Diabetic Retinopathy Study letters, central foveal thickness and macular volume at baseline and at 12 months after the first aflibercept injection was given.

RESULTS

Ninety switched eyes were included in this study. The mean (standard deviation) visual acuity was 63 (15.78) Early Treatment Diabetic Retinopathy Study letters. At baseline, the mean (standard deviation) central foveal thickness was 417.7 (158.4) μm and the mean macular volume was 9.96 (2.44) mm³. Mean change in visual acuity was +4 Early Treatment Diabetic Retinopathy Study letters (p = 0.0053). The mean change in macular volume was -1.53 mm³ in SW group (p = 0.21), while the change in central foveal thickness was -136.8 μm (p = 0.69).

CONCLUSION

There was a significant improvement in visual acuity and in anatomical outcomes in the switched group at 12 months after commencing treatment with aflibercept for diabetic macular oedema.

Kaempferol, a Major Flavonoid in Ginkgo Folium, Potentiates Angiogenic Functions in Cultured Endothelial Cells by Binding to Vascular Endothelial Growth Factor

Kaempferol is a major flavonoid in Ginkgo Folium and other edible plants, which is being proposed here to have roles in angiogenesis. Angiogenesis is important in both physiological and pathological development. Here, kaempferol was shown to bind with vascular endothelial growth factor (VEGF), probably in the heparin binding domain of VEGF: this binding potentiated the angiogenic functions of VEGF in various culture models. Kaempferol potentiated the VEGF-induced cell motility in human umbilical vein endothelial cells (HUVECs), as well as the sub-intestinal vessel sprouting in zebrafish embryos and formation of microvascular in rat aortic ring. In cultured HUVECs, application of kaempferol strongly potentiated the VEGF-induced phosphorylations of VEGFR2, endothelial nitric oxide synthase (eNOS) and extracellular signal-regulated kinase (Erk) in time-dependent and concentration-dependent manners, and in parallel the VEGF-mediated expressions of matrix metalloproteinases (MMPs), MMP-2 and MMP-9, were significantly enhanced. In addition, the potentiation effect of kaempferol was revealed in VEGF-induced migration of skin cell and monocyte. Taken together, our results suggested the pharmacological roles of kaempferol in potentiating VEGF-mediated functions should be considered.

Anti-VEGF Treatment and Response in Age-related Macular Degeneration: Disease's Susceptibility, Pharmacogenetics and Pharmacokinetics

The current review is focussing different factors that contribute and directly correlate to the onset and progression of Age-related Macular Degeneration (AMD). In particular, the susceptibility to AMD due to genetic and non-genetic factors and the establishment of risk scores, based on the analysis of different genes to measure the risk of developing the disease. A correlation with the actual therapeutic landscape to treat AMD patients from the point of view of pharmacokinetics and pharmacogenetics is also exposed. Treatments commonly used, as well as different regimes of administration, will be especially important in trying to classify individuals as "responders" and "non-responders". Analysis of different genes correlated with drug response and also the emerging field of microRNAs (miRNAs) as possible biomarkers for early AMD detection and response will be also reviewed. This article aims to provide the reader a review of different publications correlated with AMD from the molecular and kinetic point of view as well as its commonly used treatments, major pitfalls and future directions that, to our knowledge, could be interesting to assess and follow in order to develop a personalized medicine model for AMD.

Visual acuity outcomes and anti-VEGF therapy intensity in diabetic macular oedema: a real-world analysis of 28 658 patient eyes

Background/Aim

To assess visual acuity (VA) outcomes and antivascular endothelial growth factor (anti-VEGF) treatment intensity in diabetic macular oedema (DMO).

Methods

Retrospective analysis was performed in treatment-naïve patients with DMO from 2013 to 2018 using a database of aggregated de-identified electronic medical records (Vestrum Health).

Results

At 1 year, 28 658 patient eyes underwent a mean of 6.4 anti-VEGF injections, gaining a mean of +4.2 letters (95% confidence interval for mean gain: +4.0 to +4.5 letters, p<0.001). When stratified by anti-VEGF medication and by years 2013–2018, no clinically meaningful differences in injection frequency or 1-year VA change resulted. At 1 year, 50% of eyes received ≤6 injections, while <20% received 10–13 injections, representing monthly treatment. Mean letters gained at 1 year generally showed a linear relationship with mean number of anti-VEGF injections, beyond two injections. Eyes with good baseline VA (≥20/40) generally were at risk of VA loss at 1 year; those with moderately severe baseline impairment (20/70 to 20/200) who received ≥10 injections improved by a mean of +10.3 letters.

Conclusion

In clinical practice, patients with DMO undergo fewer anti-VEGF injections and exhibit worse visual gains compared with patients in randomised clinical trials. Visual outcomes correlate with treatment intensity at 1 year, with ceiling effects related to baseline VA.

Chorioretinal response to intravitreal aflibercept injection in acute central serous chorioretinopathy

AIM

To evaluate chorioretinal responses to intravitreal aflibercept injection (IAI) in patients with acute central serous chorioretinopathy (CSC).

METHODS

Seventy-one eyes from 71 patients with symptomatic CSC for less than six months were included. Thirty-five eyes received a single IAI and 36 eyes were observed without treatment. Best-corrected visual acuity (BCVA), central subfield foveal thickness (CSFT), and subfoveal choroidal thickness (SFCT) were assessed at baseline and at 1, 2, and 3mo.

RESULTS

The mean SFCT in the IAI group decreased at 1mo, rebounded at 2mo and remained stable at 3mo compared to the baseline, while significant change was not noted in the observation group. The mean CSFT decreased significantly during the 3-month study period in both groups, and was significantly lower in the IAI group at 1mo (P<0.001). A rebound of CSFT between 1 and 2mo was noted in 14 eyes (40.0%) in the IAI group and in 1 eye (2.8%) in the observation group (P<0.001). The significant visual improvement was achieved from 1mo in the IAI group, and from 2mo in the observation group. The rate of complete absorption of subretinal fluid at 3mo did not differ between the two groups. (45.7% vs 41.7%, P=0.813).

CONCLUSION

A single IAI for acute CSC induce a transient decrease in SFCT and CSFT, which implies that IAI may have a pharmacological effect on the underlying hyperpermeable choroid in acute CSC.

Pharmacokinetics of Intravitreal Anti-VEGF Drugs in Age-Related Macular Degeneration

Intravitreal administration of anti-vascular endothelial growth factor (VEGF) antibodies has become the standard treatment for Age-Related Macular Degeneration; however, the knowledge of their pharmacokinetics is limited. A comprehensive review of the preclinical and clinical pharmacokinetic data that were obtained in different studies with intravitreal bevacizumab, ranibizumab, and aflibercept has been conducted. Moreover, the factors that can influence the vitreous pharmacokinetics of these drugs, as well as the methods that were used in the studies for analytical determination, have been exposed. These anti-VEGF drugs present different charge and molecular weights, which play an important role in vitreous distribution and elimination. The pharmacokinetic parameters that were collected differ depending on the species that were involved in the studies and on physiological and pathological conditions, such as vitrectomy and lensectomy. Knowledge of the intravitreal pharmacokinetics of the anti-VEGF drugs that were used in clinical practice is of vital importance.

Potential antiedematous effects of intravitreous anti-VEGF, unrelated to VEGF neutralization

The intravitreous injection of therapeutic proteins that neutralize vascular endothelial growth factor (VEGF) family members is efficient to reduce macular edema associated with wet age-related macular degeneration (AMD), retinal vein occlusion (RVO) and diabetic retinopathy (DR). It has revolutionized the visual prognosis of patients with macular edema. The antiedematous effect is dependent on an intravitreous dose of drug, which varies between patients and requires frequent and repeated injections to maintain its effects. At the time when optimizing the duration of anti-VEGF effects is a major challenge, understanding how anti-VEGF reduces macular edema is crucial. We discuss herein how anti-VEGF exerts antiedematous effects and raise the hypothesis that mechanisms, unrelated to VEGF neutralization, might have been underestimated.

Intravitreal ranibizumab versus aflibercept following treat and extend protocol for neovascular age-related macular degeneration

PURPOSE

To assess the morphological and functional outcome and stability of the "treat and extend" protocol using aflibercept compared to ranibizumab for the treatment of eyes with neovascular age-related macular degeneration.

PATIENTS AND METHODS

This retrospective study included 100 eyes of 94 patients with primary onset neovascular age-related macular degeneration followed up for 12 months. We studied two groups of eyes: group 1, 50 eyes treated with 0.5 mg/0.05 mL ranibizumab and group 2, 50 eyes treated with 2.0 mg/0.05 mL aflibercept. During the first year, all eyes received 3 aflibercept or ranibizumab injections monthly as upload phase. Then, eyes were treated with a treat and extend algorithm. Main outcome measures included: best corrected visual acuity (BCVA), central macular thickness (CMT), and the number of injections. In addition, we compared recurrence rates between the two groups.

RESULTS

BCVA (log MAR) in group 1 vs group 2 was 0.54 ± 0.31 vs 0.49 ± 0.30 (p = 0.38) before treatment and 0.49 ± 0.33 vs 0.47 ± 0.32 (p = 0.85) after treatment. The visual improvement (decimal) was 0.05 ± 0.13 vs 0.04 ± 0.12 (p = 0.91). CMT in group 1 vs group 2 was 375.6 ± 98.3 μm vs 369.6 ± 103.7 μm (p = 0.73) before treatment and 306.3 ± 71.8 μm vs 294.8 ± 96 μm (p = 0.54) after treatment. The decrease in CMT was 69.3 ± 93 μm vs 74.8 ± 96 μm (p = 0.77). The number of injections/eye after upload phase in group 1 vs group 2 was 5.88 ± 1.4 vs 6.16 ± 1.3 (p = 0.25). Finally, major recurrence rates were statistically significantly different between the two groups (2% vs 6%, p = 0.04).

CONCLUSIONS

Significant differences regarding BCVA, central macular thickness, and the number of injections were not found between aflibercept and ranibizumab during the first year following the treat and extend protocol. However, the significantly higher major recurrence rates in the aflibercept group after extending the treatment interval to 10 weeks might suggest that aflibercept should better not to be used in longer than 8 weeks intervals during the first year of treatment.

The Systemic Safety of Ranibizumab in Patients 85 Years and Older with Neovascular Age-Related Macular Degeneration

OBJECTIVE

Ranibizumab safety is well established for treatment of neovascular age-related macular degeneration (nAMD), but less is known about the risk of systemic serious adverse events (SAEs), specifically among patients with heightened baseline risk due to age (≥85 years). This analysis examines whether patients ≥85 years of age versus those <85 years experience an increased risk of key systemic SAEs during intravitreal ranibizumab treatment for nAMD.

DESIGN

Retrospective, pooled analysis of safety data from 5 phase III/IIIb multicenter randomized clinical trials in patients with nAMD: ANCHOR, MARINA, PIER, SAILOR, and HARBOR.

PARTICIPANTS

Patients with nAMD receiving ranibizumab (n = 4347) or control (sham/verteporfin photodynamic therapy, n = 441) treatment included in the safety-evaluable set of the 5 trials.

METHODS

The incidence of nonocular SAEs was analyzed stratified by age (<85 years [n = 3795] vs ≥85 years [n = 993]), treatment (control, ranibizumab 0.3 mg, ranibizumab 0.5 mg, ranibizumab 2.0 mg), and injection frequency (monthly, as needed [PRN]).

MAIN OUTCOME MEASURES

Incidence of key systemic SAEs, defined as total nonocular SAEs, deaths, cardiovascular events, cerebrovascular (CBV) events, and Antiplatelet Trialists' Collaboration events.

RESULTS

The MARINA and ANCHOR trials had greater rates of key SAEs for patients ≥85 years versus those <85 years. Ranibizumab exposure did not increase the risk of most SAEs in elderly patients; for CBV events and death, the effect of ranibizumab versus control treatment for age ≥85 years was not interpretable due to small number of events (CBV: n = 2, 2, 5 for control, ranibizumab 0.3 mg, and ranibizumab 0.5 mg, respectively; death: n = 2, 4, 5, respectively). Across all 5 trials, an increased risk was found for age ≥85 years versus <85 years for the marketed dose of ranibizumab 0.5 mg. In the HARBOR trial, increased rates of key SAEs (excluding total nonocular SAEs) for age ≥85 years versus <85 years were observed with monthly dosing but not with PRN dosing; event rates were similar for 2.0 mg versus 0.5 mg.

CONCLUSIONS

Consistent with general trends, the risk of key systemic SAEs was associated with age ≥85 years versus <85 years, but not with ranibizumab drug exposure. The difference between monthly versus PRN was inconclusive. There was no evidence of a dose effect. Interpretation of this retrospective analysis is limited because it was not prospectively powered for statistically definitive conclusions.

Aflibercept therapy in eyes with neovascular age-related macular degeneration and its effect on choroidal thickness

BACKGROUND

The purpose of this study was to investigate changes in best-corrected visual acuity (BCVA), central macular thickness (CMT) and subfoveal choroidal thickness (SCT) after intravitreal aflibercept injections for neovascular age-related macular degeneration (NV-AMD).

METHODS

Eighty-nine eyes (48 treatment naive, 41 resistant) were included in this prospective study. All patients were treated with three consecutive monthly injections then every two months as required. BCVA, CMT and SCT were recorded and compared within and between the two groups.

RESULTS

The mean increase in BCVA after injections was 0.18 ± 0.34 logMAR in the naive group (p = 0.01) and 0.092 ± 0.38 logMAR in the resistant group (p = 0.131). The mean decrease in CMT was 200.3 ± 216.1 μm in the naive group and 183.3 ± 203.4 μm in the resistant group (p < 0.001 for both). The mean decrease in SCT was 22.1 ± 62.0 μm in the naive group (p = 0.014). The mean change in SCT was 22.28 ± 74.05 μm in the resistant group; this was not statistically significant (p = 0.061).

CONCLUSION

BCVA, CMT and SCT decreased significantly after intravitreal aflibercept injections in naive patients with NV-AMD. Despite anatomic success, functional improvement was not reached and SCT did not significantly decrease after intravitreal aflibercept injections in resistant patients.

Binding of Resveratrol to Vascular Endothelial Growth Factor Suppresses Angiogenesis by Inhibiting the Receptor Signaling

Resveratrol is a polyphenol commonly found in plants and food health products, such as grape and red wine, and was identified for its binding to vascular endothelial growth factor (VEGF) by using HerboChips screening. The binding, therefore, resulted in alterations of VEGF binding to its receptor and revealed the roles of VEGF in angiogenesis. Several lines of evidence gave support to the inhibitory activities of resveratrol in VEGF-triggered angiogenesis. In human umbilical vein endothelial cells (HUVECs), compared with a VEGF-induced group, resveratrol, at a high concentration, suppressed VEGF-mediated endothelial cell proliferation, cell migration, cell invasion, and tube formation by 80 ± 9.01%, 140 ± 3.78%, 110 ± 7.51%, and 120 ± 10.26%, respectively. Moreover, resveratrol inhibited the subintestinal vessel formation in zebrafish embryo. In signaling cascades, application of resveratrol in HUVECs reduced the VEGF-triggered VEGF receptor 2 phosphorylation and c-Jun N-terminal kinase phosphorylation. Moreover, the VEGF-mediated phosphorylations of endothelial nitric oxide synthase, protein kinase B, and extracellular signal-regulated kinase were obviously decreased by (3 ± 0.37)-, (2 ± 0.27)- and (6 ± 0.23)-fold, respectively, in the presence of resveratrol at high concentration. Parallelly, the VEGF-induced reactive oxygen species formation was significantly decreased by 50 ± 7.88% to 120 ± 14.82% under resveratrol treatment. Thus, our results provided support to the antiangiogenic roles of resveratrol, as well as its related signaling mechanisms, in attenuating the VEGF-mediated responses. The present results supported possible development of resveratrol, which should be considered as a therapeutic agent in terms of prevention and clinical treatment of diseases related to angiogenesis.

Morphology and Composition of the Inner Limiting Membrane: Species-Specific Variations and Relevance toward Drug Delivery Research

The inner limiting membrane (ILM) represents the structural boundary between the vitreous and the retina, and is suggested to act as a barrier for a wide range of retinal therapies. While it is widely acknowledged that the morphology of the human ILM exhibits regional variations and undergoes age-related changes, insight into its structure in laboratory animals is very limited. Besides presenting a detailed overview of the morphology and composition of the human ILM, this review specifically reflects on the species-specific differences in ILM structure. With these differences in mind, we furthermore summarize the most relevant reports on the barrier role of the ILM with regard to viral vectors, nanoparticles, anti-VEGF medication and stem cells. Overall, this review aims to deliberate on the impact of species-specific ILM variations on drug delivery research as well as to pinpoint knowledge gaps which future basic research should resolve.

Intravitreal dexamethasone implants versus intravitreal anti-VEGF treatment in treating patients with retinal vein occlusion: a meta-analysis

Background

Retinal vein occlusion (RVO) is a common retinal venous disorder that causes vision loss. No specific therapy has been developed. Controversy exists regarding two treatments: intravitreal dexamethasone implants and anti-vascular endothelial growth factor (VEGF). The goal of this study is to compare the effectiveness and safety of dexamethasone implants and anti-VEGF treatment for RVO.

Methods

The PubMed, Embase, and Cochrane Library databases were searched for studies comparing dexamethasone implants with anti-VEGF in patients with RVO. Best-corrected visual acuity (BCVA), central subfield thickness (CST), intraocular pressure changes, conjunctival haemorrhage, reduced VA, and macular oedema were extracted from the final included studies. RevMan 5.3 was used to conduct the quantitative analysis and bias assessment.

Results

Four randomised controlled trials assessing 969 eyes were included. The anti-VEGF treatment showed better BCVA improvement (mean difference [MD] = − 10.59, P < 0.00001) and more CST decrease (MD = − 86.71 μm, P = 0.02) than the dexamethasone implants. However, the dexamethasone implants required fewer injections. As for adverse effects, the dexamethasone implants showed significantly higher intraocular pressure (IOP) and more cataracts than the anti-VEGF treatment. No significant differences were found in conjunctival haemorrhage, reduced VA, and macular oedema.

Conclusions

Anti-VEGF treatment showed better functional and anatomical improvement with less risk of IOP elevation and cataract formation compared to dexamethasone implants. Thus, anti-VEGF treatment is the first choice for treating RVO patients.

New concepts in the diagnosis and management of choroidal metastases

The most frequent site of ocular metastasis is the choroid. The occurrence of choroidal metastases has increased steadily due to the longer survival of metastatic patients and the improvement of diagnostic tools. Fundoscopy, ultrasonography, and fluorescein angiography are now complemented by indocyanine green angiography and optical coherence tomography. Choroidal tumor biopsy may also confirm the metastatic nature of the tumor and help to determine the site of the primary malignancy. There is currently no consensus on the treatment strategy. Most patients have a limited life expectancy and for these complex treatments are generally not recommended. However, recent advances in systemic therapy have significantly improved survival of certain patients who may benefit from an aggressive ocular approach that could preserve vision. Although external beam radiation therapy is the most widely used treatment, more advanced forms of radiotherapy that are associated with fewer side effects can be proposed in select cases. In patients with a shorter life expectancy, systemic therapies such as those targeting oncogenic drivers, or immunotherapy can induce a regression of the choroidal metastases, and may be sufficient to temporarily decrease visual symptoms. However, they often acquire resistance to systemic treatment and ocular relapse usually requires radiotherapy for durable control. Less invasive office-based treatments, such as photodynamic therapy and intravitreal injection of anti-VEGF, may also help to preserve vision while reducing time spent in medical settings for patients in palliative care. The aim of this review is to summarize the current knowledge on choroidal metastases, with emphasis on the most recent findings in epidemiology, pathogenesis, diagnosis and treatment.

Overview of Antibody Drug Delivery

Monoclonal antibodies (mAbs) are one of the most important classes of therapeutic proteins, which are used to treat a wide number of diseases (e.g., oncology, inflammation and autoimmune diseases). Monoclonal antibody technologies are continuing to evolve to develop medicines with increasingly improved safety profiles, with the identification of new drug targets being one key barrier for new antibody development. There are many opportunities for developing antibody formulations for better patient compliance, cost savings and lifecycle management, e.g., subcutaneous formulations. However, mAb-based medicines also have limitations that impact their clinical use; the most prominent challenges are their short pharmacokinetic properties and stability issues during manufacturing, transport and storage that can lead to aggregation and protein denaturation. The development of long acting protein formulations must maintain protein stability and be able to deliver a large enough dose over a prolonged period. Many strategies are being pursued to improve the formulation and dosage forms of antibodies to improve efficacy and to increase the range of applications for the clinical use of mAbs.

Aflibercept Versus Bevacizumab and/or Ranibizumab for Recurrent Macular Edema Secondary to Central Retinal Vein Occlusion

PURPOSE

To compare functional and anatomic outcomes of treatment with intravitreal aflibercept versus bevacizumab and/or ranibizumab in patients with recurrent macular edema (ME) secondary to central retinal vein occlusion (CRVO).

METHODS

Retrospective, comparative case series of patients with recurrent ME in the setting of CRVO. Patients with recurrent ME received treatment with aflibercept (Group 1, G1) or bevacizumab and/or ranibizumab (Group 2, G2). Primary outcome measures were best-corrected visual acuity (BCVA) and central foveal thickness (CFT).

RESULTS

Of the 20 eyes (20 patients) with recurrent ME included in the study, 9 received aflibercept (G1) and 11 received bevacizumab and/or ranibizumab (G2). Median BCVA at recurrence of ME and at most recent follow-up was 20/60 (G1) and 20/80 (G2) and 20/40 (G1) and 20/50 (G2, P > 0.05 for all comparisons), respectively. Median CFT at recurrence of ME and at most recent follow-up was 492 μm (G1) and 448 μm (G2) and 291 μm (G1) and 295 μm (G2, P > 0.05 for all comparisons), respectively. Complete resolution of ME for at least 4 months was found in 78% (G1) and 55% (G2) of patients with a median injection free interval of 11 (G1) and 13 (G2) months (P > 0.05).

CONCLUSIONS

In patients with recurrent ME secondary to CRVO, there was improvement in BCVA and CFT in all groups, although patients treated with aflibercept showed a trend toward better anatomical outcomes decreased need for recurrent injections.

Management of diabetic macular edema in Japan: a review and expert opinion

Diabetic retinopathy is a frequent cause of visual impairment in working-age adults (≥ 30 years) and in Japan is most commonly observed in those aged 50-69 years. Diabetic macular edema (DME) is one of the main causes of vision disturbance in diabetic retinopathy, which is a clinically significant microvascular complication of diabetes. Anti-vascular endothelial growth factor (VEGF) therapy is becoming the mainstay of treatment for DME. However, to achieve sustained long-term improvement in visual acuity, conventional laser photocoagulation, vitrectomy and steroid therapy are also expected to play a role in the treatment of DME. This review summarizes the epidemiology and pathology of diabetic retinopathy and DME, evaluates the findings regarding the diagnosis and treatment of DME, and underscores the importance of systemic management of the disease in the context of the current health care situation in Japan. Finally, the unmet needs of patients with DME and prospects for research are discussed. The weight of evidence suggests that it is important to establish a multipronged treatment strategy centered on anti-VEGF therapy.

Generation and characterization of ABBV642, a dual variable domain immunoglobulin molecule (DVD-Ig) that potently neutralizes VEGF and PDGF-BB and is designed for the treatment of exudative age-related macular degeneration

Exudative age-related macular degeneration (AMD) is the most common cause of moderate and severe vision loss in developed countries. Intraocular injections of vascular endothelial growth factor (VEGF or VEGF-A)-neutralizing proteins provide substantial benefit, but frequent, long-term injections are needed. In addition, many patients experience initial visual gains that are ultimately lost due to subretinal fibrosis. Preclinical studies and early phase clinical trials suggest that combined suppression of VEGF and platelet-derived growth factor-BB (PDGF-BB) provides better outcomes than suppression of VEGF alone, due to more frequent regression of neovascularization (NV) and suppression of subretinal fibrosis. We generated a dual variable domain immunoglobulin molecule, ABBV642 that specifically and potently binds and neutralizes VEGF and PDGF-BB. ABBV642 has been optimized for treatment of exudative AMD based on the following design characteristics: 1) high affinity binding to all VEGF-A isoforms and both soluble and extracellular matrix (ECM)-associated PDGF-BB; 2) potential for extended residence time in the vitreous cavity to decrease the frequency of intraocular injections; 3) rapid clearance from systemic circulation compared with molecules with wild type Fc region for normal FcRn binding, which may reduce the risk of systemic complications; and 4) low risk of potential effector function. The bispecificity of ABBV642 allows for a single injection of a single therapeutic agent, and thus a more streamlined development and regulatory path compared with combination products. In a mouse model of exudative AMD, ABBV642 was observed to be more effective than aflibercept. ABBV642 has potential to improve efficacy with reduced injection frequency in patients with exudative AMD, thereby reducing the enormous disease burden for patients and society.

Mystery of Retinal Vein Occlusion: Vasoactivity of the Vein and Possible Involvement of Endothelin-1

Retinal vein occlusion (RVO) is a common vascular disease of retina; however, the pathomechanism leading to RVO is not yet clear. In general, increasing age, hypertension, arteriosclerosis, diabetes mellitus, dyslipidemia, cardiovascular disorder, and cerebral stroke are systemic risk factors of RVO. However, RVO often occur in the unilateral eye and sometimes develop in young subjects who have no arteriosclerosis. In addition, RVO show different variations on the degrees of severity; some RVO are resolved without any treatment and others develop vision-threatening complications such as macular edema, combined retinal artery occlusion, vitreous hemorrhage, and glaucoma. Clinical conditions leading to RVO are still open to question. In this review, we discuss how to treat RVO in practice by presenting some RVO cases. We also deliver possible pathomechanisms of RVO through our clinical experience and animal experiments.

Transfer of single dose of intravitreal injection of ranibizumab and bevacizumab into milk of sheep

AIM

To investigate whether single-dose intravitreal injections of bevacizumab and ranibizumab transfer into milk.

METHODS

This study included lactating 12 sheep and a single 3-month old suckling lamb of each sheep. Two groups consisting of 6 sheep and their lambs were constituted; the ranibizumab group and the bevacizumab group before the administration of intravitreal injections, blood and milk samples were obtained from all sheep and, following the injections, blood and milk samples of all sheep and blood samples of all lambs were collected at regular time points. Serum and milk concentrations of bevacizumab and ranibizumab were measured using an enzyme-linked immunosorbent assay (ELISA) kit. The limit of determination was 0.9 ng/mL for bevacizumab and 0.62 ng/mL for ranibizumab.

RESULTS

At 6h after intravitreal injections, bevacizumab concentration was above the limit of determination in the blood of all sheep. At 3wk, when the study was terminated, bevacizumab concentrations were high in 4 sheep. Even though bevacizumab concentrations in milk showed fluctuations, the drug transferred into the milk of all sheep at detectable concentrations. Ranibizumab drug concentrations in the blood and milk of sheep and those in the blood of lambs were below the limit of determination by the ELISA kit.

CONCLUSION

This sheep model study demonstrate that intravitreal injection of ranibizumab, which did not transfer into the milk of sheep and suckling lambs, is safer than bevacizumab during lactation period.

Aflibercept in age-related macular degeneration: evaluating its role as a primary therapeutic option

The recent VIEW studies have demonstrated the non-inferiority of monthly and bi-monthly aflibercept in the management of wet age related macular degeneration (AMD) compared with ranibizumab. However, the current data are limited mainly to fixed dosing regimens with few studies looking at flexible dosing regimens of aflibercept in wet AMD. In addition, recent data from the VIEW 96 week extension has shown that patients being shifted from fixed dosing regimens to PRN have shown a drop in visual acuity and increase in central macular thickness. This is an indication that fixed dosing, a non-sustainable option, is only effective as long as it is continued. Regimens such as treat and extend (TAE) and pro-re nata (PRN) have been studied extensively in ranibizumab and bevacizumab and have shown to be effective options. With the presence of effective, established and less costly drugs such as ranibizumab and bevacizumab, the role of aflibercept as a primary treatment modality has yet to be clearly defined. The current review provides an analysis of the VIEW studies, as well as the extension phases. It also looks at post hoc analysis of predictors of response and outcomes. We have also conducted a search on studies comparing between PRN regimens using aflibercept and other anti-VEGF agents. This review also explores cheaper off label aflibercept; ziv-aflibercept in the treatment of wet AMD. The main purpose of the review is to delineate the role of aflibercept as a primary therapeutic option and if there are any significant advantages that would advocate its use over alternative anti-VEGF drugs. Finally, we propose a treatment algorithm for patients being started on aflibercept during the first year and thereafter.

Therapeutic Options in Refractory Diabetic Macular Oedema

Diabetic macular oedema (DMO) results from alterations of several biochemical pathways in diabetic eyes. Centre-involving DMO is an important cause of visual loss in diabetes. Anti-vascular endothelial growth factor agents are now the mainstay of centre-involving DMO treatment. Oedema that does not achieve optimal response to these agents occurs in a sizeable proportion of eyes and is called refractory or persistent DMO. Management of refractory DMO is challenging. In this paper, the pathophysiology of DMO, and the definitions used in various studies are summarised. Therapeutic options for refractory DMO management including corticosteroids, laser, combination therapies, and surgery are explored. Novel agents on the horizon for DMO control that are being investigated at present are discussed as well. A literature review was performed and a summary of the research studies for each of the agents is provided in order to guide the reader regarding the existing evidence for their application in DMO. Importance of early recognition of disease and prompt treatment to achieve best visual outcome is discussed. Utility of optical coherence tomography to guide disease diagnosis and monitoring is highlighted. An algorithmic approach for DMO management is described. Finally, the impact that personalized medicine and genetics might have on DMO management is assessed.