Simultaneous dexamethasone intravitreal implant and anti-VEGF therapy for neovascular age-related macular degeneration resistant to anti-VEGF monotherapy

Simultaneous Intravitreal Steroid and Anti-VEGF Therapy for Monotherapy-Resistant Chronic Wet Age-Related Macular Degeneration

BACKGROUND AND OBJECTIVE

The purpose of this study was to analyze the safety and efficacy of combined intravitreal anti-vascular endothelial growth factor (anti-VEGF) and steroid therapeutic agents for resistant choroidal neovascularization (CNV). A retrospective observational clinical study was performed assessing anatomic and visual changes in a consecutive cohort of patients with refractory chronic wet age-related macular degeneration resistant to high-dose aflibercept therapy.

PATIENTS AND METHODS

Twelve eyes of 12 patients with unresponsive CNV despite aggressive monthly anti-VEGF (4-mg aflibercept [mean: 43.75 ± SD23.08]) were included. Combination consisted of simultaneous administration of anti-VEGF and corticosteroids. Study measures evaluated visual acuity, central retinal thickness (CRT), and intraocular pressure.

RESULTS

Paired tests revealed significant CRT reduction from the baseline at the 1-month (388.58 ± 89.31 versus 334.00 ± 92.88, P = 0.0117), 2-month (388.58 ± 89.31 versus 312.08 ± 75.61, P = 0.0185), and 3-month (388.53 ± 89.31 versus 304.56 ± 53.28, P = 0.046) visit. The Kaplan-Meier curve showed a median time of remission (no retinal fluid) of 70 days (95% CI 53, 147 days).

CONCLUSION

Combination treatment demonstrated clear anatomic improvement in eyes with anti-VEGF-resistant CNV. [Ophthalmic Surg Lasers Imaging Retina 2024;55:XX-XX.].

Intravitreal Dexamethasone as a Rescue for Anti-Vascular Endothelial Growth Factor Therapy in Neovascular Age-Related Macular Degeneration with Persistent Disease Activity and High Treatment Demand

Purpose: To assess the impact of switching to, or adding, an intravitreal dexamethasone implant (Dex; Ozurdex®) in anti-vascular endothelial growth factor (VEGF) therapy on disease stability and treatment intervals in eyes with neovascular age-related macular degeneration (nAMD) and persistent disease activity and high treatment demand. Methods: This retrospective noncomparative multicenter longitudinal case series included pseudophakic eyes with nAMD and persistent retinal fluid despite regular anti-VEGF therapy (ranibizumab or aflibercept) that received at least 1 intravitreal Dex implant. Visual acuity, central retinal thickness (CRT), and intraocular pressure were recorded before, and after, the addition of Dex to anti-VEGF therapy. Results: Sixteen eyes of 16 patients met the inclusion criteria of persistent fluid despite anti-VEGF therapy, under treatment intervals of ≤7 weeks in 14 instances. Patients were 80.9 ± 7.4 years old and had received 25.5 ± 17.4 anti-VEGF injections before Dex over a period of 36.4 ± 21.9 months before switching. The treatment interval increased from 5.5 ± 3.2 weeks between the last anti-VEGF and first Dex injection to 11.7 ± 7.3 weeks thereafter (P = 0.022). CRT remained stable (385.3 ± 152.1, 383.9 ± 129.7, and 458.3 ± 155.2 μm before switching as well as 12 and 24 months after switching; P = 0.78 and P = 0.36, respectively). An insignificant mean short-term early increase in visual acuity was not sustained over time. Conclusions: The addition of Dex resulted in a relevant and sustained increase in treatment intervals, whereas CRT and visual acuity remained stable in these difficult-to-treat eyes. It may be discussed whether inflammation or other steroid-responsive factors play a significant role in cases of nAMD with nonsatisfactory responses to anti-VEGF.

Periodontitis and Outer Retinal Thickness: a Cross-Sectional Analysis of the United Kingdom Biobank Cohort

Purpose

Periodontitis, a ubiquitous severe gum disease affecting the teeth and surrounding alveolar bone, can heighten systemic inflammation. We investigated the association between very severe periodontitis and early biomarkers of age-related macular degeneration (AMD), in individuals with no eye disease.

Design

Cross-sectional analysis of the prospective community-based cohort United Kingdom (UK) Biobank.

Participants

Sixty-seven thousand three hundred eleven UK residents aged 40 to 70 years recruited between 2006 and 2010 underwent retinal imaging.

Methods

Macular-centered OCT images acquired at the baseline visit were segmented for retinal sublayer thicknesses. Very severe periodontitis was ascertained through a touchscreen questionnaire. Linear mixed effects regression modeled the association between very severe periodontitis and retinal sublayer thicknesses, adjusting for age, sex, ethnicity, socioeconomic status, alcohol consumption, smoking status, diabetes mellitus, hypertension, refractive error, and previous cataract surgery.

Main Outcome Measures

Photoreceptor layer (PRL) and retinal pigment epithelium-Bruch's membrane (RPE-BM) thicknesses.

Results

Among 36 897 participants included in the analysis, 1571 (4.3%) reported very severe periodontitis. Affected individuals were older, lived in areas of greater socioeconomic deprivation, and were more likely to be hypertensive, diabetic, and current smokers (all P < 0.001). On average, those with very severe periodontitis were hyperopic (0.05 ± 2.27 diopters) while those unaffected were myopic (-0.29 ± 2.40 diopters, P < 0.001). Following adjusted analysis, very severe periodontitis was associated with thinner PRL (-0.55 μm, 95% confidence interval [CI], -0.97 to -0.12; P = 0.022) but there was no difference in RPE-BM thickness (0.00 μm, 95% CI, -0.12 to 0.13; P = 0.97). The association between PRL thickness and very severe periodontitis was modified by age (P < 0.001). Stratifying individuals by age, thinner PRL was seen among those aged 60 to 69 years with disease (-1.19 μm, 95% CI, -1.85 to -0.53; P < 0.001) but not among those aged < 60 years.

Conclusions

Among those with no known eye disease, very severe periodontitis is statistically associated with a thinner PRL, consistent with incipient AMD. Optimizing oral hygiene may hold additional relevance for people at risk of degenerative retinal disease.

Financial Disclosures

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

Real-World Data on Faricimab Switching in Treatment-Refractory Neovascular Age-Related Macular Degeneration

Faricimab is a newly approved bispecific antibody for neovascular age-related macular degeneration (nAMD). Our study aims to evaluate clinical outcomes of faricimab switching in patients with treatment-refractory nAMD; determine parameters that predict these outcomes; and obtain patient subjective experience on this new injection. This is a retrospective case review with clinical and imaging data from a tertiary referral unit (Birmingham and Midland Eye Centre, UK), involving patients who were switched to faricimab between 1 January and 1 December 2023. In all, 63 eyes (54 patients) with a mean age of 79.2 ± 7.8 and mean of 41.5 ± 22.4 previous anti-VEGF injections were analysed. With a mean of 4.81 ± 1.16 faricimab injections over 6.98 ± 1.75 months, post-treatment visual acuity was logMAR 0.49 ± 0.36 and central macular thickness (CMT) was 320.3 ± 97.9 µm. After first dose, 39.1% achieved complete dryness and 89.1% had anatomical improvement. Presence of subretinal fluid was a predictor of better functional outcomes (p = 0.001, β = -0.182), while initial CMT predicted better anatomical outcomes (p = 0.001, β = 0.688). Compared to their experiences of previous anti-VEGF injections, 89% of patients reported no more discomfort and 87.0% experienced no more floaters, photopsia, or bubbles post-injection. Faricimab switching has anatomical efficacy but limited functional improvement in treatment-refractory AMD. Patient experiences of faricimab compared to previous injections were overall positive.

SUSTAINED BIWEEKLY AFLIBERCEPT FOR REFRACTORY NEOVASCULAR AGE-RELATED MACULAR DEGENERATION: The Prospective TRISTAR Study

PURPOSE

To assess the safety and efficacy of biweekly (every 2 weeks) intravitreal aflibercept injections (IAI) 2 mg in eyes with refractory neovascular age-related macular degeneration (NVAMD).

METHODS

A prospective, single-arm, interventional study was conducted. Eyes with refractory NVAMD received six biweekly IAIs through week 12, followed by a 4-week treatment pause until week 16. Eyes with residual subretinal fluid (SRF) at week 16 were randomized 1:1 to either four additional biweekly IAIs or to 4-week (q4W) IAI dosing through week 24. All eyes were subsequently treated q4W through week 52.

RESULTS

Enrolled eyes (n = 22) had persistent SRF despite a mean of 11.8 injections over the prior 12 months. One patient developed endophthalmitis at week 12. There were no additional drug/procedure-related adverse events. Best-corrected visual acuity (BCVA) improved significantly from baseline to week 14 (2.52 letters, P < 0.001). The mean central subfield thickness (CST) was also significantly improved at week 14 (-31.9 µ m, P < 0.001) with eight of 22 eyes achieving complete SRF resolution. Only two of eight eyes remained free of SRF at week 16, with a corresponding increase in mean CST of 26.7 µ m compared with week 14. By week 52, improvements in BCVA and CST were lost.

CONCLUSION

In patients with refractory NVAMD-related SRF, sustained biweekly IAIs resulted in significant functional and anatomical improvements during biweekly dosing. These gains, however, were lost on return to monthly dosing. These findings suggest that efforts to reduce refractory SRF in NVAMD with biweekly dosing may provide added benefit compared with standard of care treatment if biweekly dosing is sustained.

Nanofiber-coated implants: Development and safety after intravitreal application in rabbits

Intravitreal injections are the preferred choice for drug administration to the posterior segment of the eye. However, the required frequent injections may cause complications to the patient and low adherence to the treatment. Intravitreal implants are able to maintain therapeutic levels for a long period. Biodegradable nanofibers can modulate drug release and allow the incorporation of fragile bioactive drugs. Age-related macular degeneration is one of the world major causes of blindness and irreversible vision loss. It involves the interaction between VEGF and inflammatory cells. In this work we developed nanofiber-coated intravitreal implants containing dexamethasone and bevacizumab for simultaneously delivery of these drugs. The implant was successfully prepared and the efficiency of the coating process was confirmed by scanning electron microscopy. Around 68% of dexamethasone was released in 35 days and 88% of bevacizumab in 48hs. The formulation presented activity in the reduction of vessels and was safe to the retina. It was not observed any clinical or histopathological change, neither alteration in retina function or thickness by electroretinogram and optical coherence tomography during 28 days. The nanofiber-coated implants of dexamethasone and bevacizumab may be considered as a new delivery system that can be effective for the treatment of AMD.

Simultaneous Release of Aflibercept and Dexamethasone from an Ocular Drug Delivery System

PURPOSE

Intravitreal injections of anti-vascular endothelial growth factors (anti-VEGF) are the current standard of care for patients with choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD). There is a growing subset of patients that does not respond to anti-VEGF monotherapy treatment. Some patients, however, do respond to combination therapy of corticosteroids and anti-VEGF. This treatment requires monthly/bimonthly injections of anti-VEGF and semi-annual injections of corticosteroid. A drug delivery system (DDS) that simultaneously releases multiple drugs could benefit these patients by reducing the number of injections. The purpose of this study was to characterize the simultaneous release of aflibercept and dexamethasone from a biodegradable microparticle- and nanoparticle-hydrogel DDS.

METHODS

Dexamethasone-loaded nanoparticles and aflibercept-loaded microparticles were created using modified single- and double-emulsion techniques, respectively. Then, microparticles and nanoparticles were embedded into a thermoresponsive, biodegradable poly(ethylene glycol)-co-(L-lactic acid) diacrylate (PEG-PLLA-DA)-N-isopropylacrylamide (NIPAAm) hydrogel DDS. Drug release studies and characterization of DDS were conducted with varying doses of microparticles and nanoparticles.

RESULTS

The combination aflibercept-loaded microparticle- and dexamethasone-loaded nanoparticle- hydrogel (Combo-DDS) achieved a total release time of 224 days. Small decreases were seen in swelling ratio and equilibrium water content for Combo-DDS compared to monotherapy aflibercept-loaded microparticle-hydrogel DDS (AFL-DDS) and monotherapy dexamethasone-loaded nanoparticle-hydrogel DDS (DEX-DDS). Bioactivity of aflibercept was maintained in Combo-DDS compared to AFL-DDS.

CONCLUSIONS

The Combo-DDS was able to extend and control the release of both aflibercept and dexamethasone simultaneously from a single DDS. This may eliminate the need for separate dosing regiments of anti-VEGF and corticosteroids for wet AMD patients.

Comparison of Intraocular Cytokine Levels of Choroidal Neovascularization Secondary to Different Retinopathies

Purpose: To investigate and compare the aqueous concentrations of vascular endothelial growth factor (VEGF) and other inflammatory cytokines in various choroidal neovascularization (CNV) diseases and types.

Methods: This observational study included 127 naive eyes with CNV and 43 control eyes with cataracts. Aqueous humor (AH) samples were obtained prior to intravitreal anti-VEGF injection or cataract surgery. Multiple inflammatory cytokines, including VEGF, interleukin (IL) 6, IL-8, IL-10, interferon-inducible protein 10 (IP-10), and monocyte chemotactic protein 1 (MCP-1) levels, were measured using a multiplex bead assay. The angiogenesis index was defined as the ratio of IP-10 to MCP-1. In addition, the relationship among AH cytokine levels, central macular thickness (CMT), and CNV size on optical coherence tomography angiography (OCTA) was evaluated.

Results: Except in the myopic CNV group (P = 0.452), the AH concentration of VEGF was significantly higher in all other CNV groups than in the control group (P < 0.05 for all comparisons). IL-8, IL-10, IP-10, and MCP-1 levels (P < 0.05 for all groups) were significantly higher in all CNV diseases except those with neovascular central serous chorioretinopathy. The angiogenesis index was significantly higher in all CNV diseases (P < 0.05 for all comparisons). The VEGF level may be associated with the size of the CNV on OCTA (p = 0.043).

Conclusions: The level of intraocular inflammatory cytokines varied among different CNV diseases and CNV types. Therefore, the angiogenesis index may be a more sensitive indicator of angiogenesis.

Dexamethasone implant improves anatomic response to anti-VEGF therapy in treatment-resistant polypoidal choroidal vasculopathy

BACKGROUND

A significant proportion of eyes with polypoidal choroidal vasculopathy (PCV) can be resistant to anti-vascular endothelial growth factor (VEGF) injections. We evaluated the efficacy of a combination of dexamethasone intravitreal implant (DXI) and anti-VEGF therapy in eyes resistant to anti-VEGF monotherapy.

METHODS

In this retrospective study, patients with PCV resistant to anti-VEGF injections were additionally injected with a DXI along with an anti-VEGF agent. Best-corrected visual acuity (BCVA), slit-lamp examination, fundus evaluation, and optical coherence tomography (OCT) data were analyzed. Anatomical response on OCT was the primary outcome measure. Change in visual acuity and injection-free interval after DXI were evaluated as secondary outcome measures.

RESULTS

Twelve eyes of 11 patients were included in the study. Mean age of patients at presentation was 64.7 ± 9.5 years (range, 49-78.8 years), and there were seven females (63.6%). Median number of anti-VEGF injections prior to DXI was 4 (interquartile range IQR, 3-7). Median follow-up duration after DXI was 32.2 months (IQR, 6.6-41.6 months). Median logMAR BCVA immediately prior to DXI was 0.41 (IQR, 0.30-0.88) and after injection was 0.40 (IQR, 0.30-1.05), which was not significantly different (p = 0.85). Median Central Retinal Thickness (CRT) after DXI was 305.5 µm (IQR, 249-409 µm), which was significantly (p = 0.003) lesser than pre-injection thickness of 547 µm (IQR, 431-771 µm). Median injection-free interval in these eyes after DXI was 5 months (IQR, 2.8-6.4 months). Kaplan-Meier estimates of first injection after DXI were 27.3% at 3 months, 67.3% at 6 months, and 89.1% at 12 months.

CONCLUSIONS

Dexamethasone implant combined with anti-VEGF treatment can prolong the treatment-free interval in eyes with PCV resistant to anti-VEGF injection while maintaining visual acuity.

Anti-VEGF-Resistant Retinal Diseases: A Review of the Latest Treatment Options

Anti-vascular endothelial growth factor (anti-VEGF) therapy currently plays a central role in the treatment of numerous retinal diseases, most notably exudative age-related macular degeneration (eAMD), diabetic retinopathy and retinal vein occlusions. While offering significant functional and anatomic benefits in most patients, there exists a subset of 15–40% of eyes that fail to respond or only partially respond. For these cases, various treatment options have been explored with a range of outcomes. These options include steroid injections, laser treatment (both thermal therapy for retinal vascular diseases and photodynamic therapy for eAMD), abbreviated anti-VEGF treatment intervals, switching anti-VEGF agents and topical medications. In this article, we review the effectiveness of these treatment options along with a discussion of the current research into future directions for anti-VEGF-resistant eyes.

Dexamethasone Loaded Liposomes by Thin-Film Hydration and Microfluidic Procedures: Formulation Challenges

Liposomes have been one of the most exploited drug delivery systems in recent decades. However, their large-scale production with low batch-to-batch differences is a challenge for industry, which ultimately delays the clinical translation of new products. We have investigated the effects of formulation parameters on the colloidal and biopharmaceutical properties of liposomes generated with a thin-film hydration approach and microfluidic procedure. Dexamethasone hemisuccinate was remotely loaded into liposomes using a calcium acetate gradient. The liposomes produced by microfluidic techniques showed a unilamellar structure, while the liposomes produced by thin-film hydration were multilamellar. Under the same remote loading conditions, a higher loading capacity and efficiency were observed for the liposomes obtained by microfluidics, with low batch-to-batch differences. Both formulations released the drug for almost one month with the liposomes prepared by microfluidics showing a slightly higher drug release in the first two days. This behavior was ascribed to the different structure of the two liposome formulations. In vitro studies showed that both formulations are non-toxic, associate to human Adult Retinal Pigment Epithelial cell line-19 (ARPE-19) cells, and efficiently reduce inflammation, with the liposomes obtained by the microfluidic technique slightly outperforming. The results demonstrated that the microfluidic technique offers advantages to generate liposomal formulations for drug-controlled release with an enhanced biopharmaceutical profile and with scalability.

Adding a Corticosteroid or Switching to Another Anti-VEGF in Insufficiently Responsive Wet Age-Related Macular Degeneration

Purpose

To compare the effect of adding a corticosteroid or switching to another anti-VEGF treatment in patients with exudative age-related macular degeneration (eAMD) with persisting intraretinal fluid on anti-VEGF monotherapy.

Methods

This retrospective, interventional case series involved 43 pseudophakic eyes with eAMD and persistent intraretinal fluid on anti-VEGF treatment that switched treatment to a combination of Ozurdex^® or Triamcinolone and anti-VEGF therapy (group 1) or to another anti-VEGF agent (group 2). The number of injections, time to re-injection, change in central retinal thickness (CRT), and best-corrected visual acuity (BCVA) from 12 months prior to 12 months after switch to third-line therapy were defined as primary outcomes.

Results

Whereas the treatment demand was reduced (from 8.8±2.2 to 4.6±2.9 injections; p=0.001) and the re-injection interval extended in group 1 (from 1.5±0.4 months to 4.4±3.8 months; p=0.001), these parameters did not change in group 2 (7.4±1.6 to 7.3±2.2; p=0.90 and 1.7±0.3 months to 1.9±0.8 months; p=0.75). Mean CRT decreased from 455.7±30.1 and 427.6±36.0µm (groups 1 and 2, respectively) to 359.1±38.2 and 303.1±44.4µm (intergroup p=0.03). The mean baseline BCVA of 62.6±3.8 letters (group 1) and 63.0±1.9 letters (group 2) remained stable under therapy in both groups (intergroup p=0.67).

Conclusion

In eyes with eAMD with persistent intraretinal fluid on anti-VEGF monotherapy despite frequent re-injections, corticosteroids achieved a similar functional and morphological outcome over 12 months as switching to another anti-VEGF therapy, but with a reduced injection burden. In selected cases, corticosteroid treatment may thus be an option for third-line therapy in refractory exudative AMD.

Establishing Liposome-Immobilized Dexamethasone-Releasing PDMS Membrane for the Cultivation of Retinal Pigment Epithelial Cells and Suppression of Neovascularization

Age-related macular degeneration (AMD) is the eye disease with the highest epidemic incidence, and has great impact on the aged population. Wet-type AMD commonly has the feature of neovascularization, which destroys the normal retinal structure and visual function. So far, effective therapy options for rescuing visual function in advanced AMD patients are highly limited, especially in wet-type AMD, in which the retinal pigmented epithelium and Bruch's membrane structure (RPE-BM) are destroyed by abnormal angiogenesis. Anti-VEGF treatment is an effective remedy for the latter type of AMD; however, it is not a curative therapy. Therefore, reconstruction of the complex structure of RPE-BM and controlled release of angiogenesis inhibitors are strongly required for sustained therapy. The major purpose of this study was to develop a dual function biomimetic material, which could mimic the RPE-BM structure and ensure slow release of angiogenesis inhibitor as a novel therapeutic strategy for wet AMD. We herein utilized plasma-modified polydimethylsiloxane (PDMS) sheet to create a biomimetic scaffold mimicking subretinal BM. This dual-surface biomimetic scaffold was coated with laminin and dexamethasone-loaded liposomes. The top surface of PDMS was covalently grafted with laminin and used for cultivation of the retinal pigment epithelial cells differentiated from human induced pluripotent stem cells (hiPSC-RPE). To reach the objective of inhibiting angiogenesis required for treatment of wet AMD, the bottom surface of modified PDMS membrane was further loaded with dexamethasone-containing liposomes via biotin-streptavidin linkage. We demonstrated that hiPSC-RPE cells could proliferate, express normal RPE-specific genes and maintain their phenotype on laminin-coated PDMS membrane, including phagocytosis ability, and secretion of anti-angiogenesis factor PEDF. By using in vitro HUVEC angiogenesis assay, we showed that application of our membrane could suppress oxidative stress-induced angiogenesis, which was manifested in decreased secretion of VEGF by RPE cells and suppression of vascularization. In conclusion, we propose modified biomimetic material for dual delivery of RPE cells and liposome-enveloped dexamethasone, which can be potentially applied for AMD therapy.