Geographic atrophy: current and future therapeutic agents and practical considerations for retinal specialists

PURPOSE OF REVIEW

Geographic atrophy (GA) from age-related macular degeneration (AMD) remains a leading cause of vision loss. The purpose of this review is to summarize currently available intravitreal therapeutics, and discuss pipeline therapeutics that are currently in clinical trials.

RECENT FINDINGS

The FDA approval of pegcetacoplan and avacincaptad pegol, both approved in 2023, represent the first therapeutics to treat GA. These are delivered via intravitreal injections, and have been shown to slow progression of GA. Both drugs have a risk of new onset neovascular age-related macular degeneration (nAMD). Initial indications seem to be that pegcetacoplan therapy has higher risks of inflammation, vasculitis, and nonarteritic ischemic optic neuropathy (NAION) as compared to avacincaptad pegol, but more real-world data will help to clarify this further. Pipeline therapeutics that we discuss include intravitreal gene therapy, oral anticomplement therapy, and intravitreal injections of a novel glycoprotein.

SUMMARY

Both pegcetacoplan and avacincaptad pegol are FDA approved to treat GA. The decision to treat patients is still complex and nuanced, but the approval of two treatments for GA is a tremendous advance in our field. Future therapeutics may further refine our ability to treat patients more effectively and safely.

Intravitreal aflibercept 8 mg in neovascular age-related macular degeneration (PULSAR): 48-week results from a randomised, double-masked, non-inferiority, phase 3 trial

BACKGROUND

Intravitreal aflibercept 8 mg could improve treatment outcomes and provide sustained disease control in patients with neovascular age-related macular degeneration (nAMD), with extended dosing compared with aflibercept 2 mg.

METHODS

PULSAR is a phase 3, randomised, three-group, double-masked, non-inferiority, 96-week trial conducted across 223 sites worldwide. Adults with nAMD were randomised 1:1:1 to aflibercept 8 mg every 12 weeks (8q12), aflibercept 8 mg every 16 weeks (8q16), or aflibercept 2 mg every 8 weeks (2q8), following three initial monthly doses in all groups. From week 16, patients in the aflibercept 8 mg groups had their dosing interval shortened if pre-specified dose regimen modification criteria denoting disease activity were met. The primary endpoint was change from baseline in best-corrected visual acuity (BCVA) at week 48. All patients with at least one dose of study treatment were included in the efficacy and safety analyses. This trial is registered with ClinicalTrials.gov (NCT04423718) and is ongoing.

FINDINGS

Of 1011 patients randomised to aflibercept 8q12 (n=336), 8q16 (n=338), or 2q8 (n=337) between Aug 11, 2020, and July 30, 2021, 1009 patients received study treatment (aflibercept 8q12 n=335; aflibercept 8q16 n=338; and aflibercept 2q8 n=336). Aflibercept 8q12 and 8q16 showed non-inferior BCVA gains versus aflibercept 2q8 (mean BCVA change from baseline +6·7 [SD 12·6] and +6·2 [11·7] vs +7·6 [12·2] letters). The least squares mean differences between aflibercept 8q12 versus 2q8 and 8q16 versus 2q8, respectively, were -0·97 (95% CI -2·87 to 0·92) and -1·14 (-2·97 to 0·69) letters (non-inferiority margin at 4 letters). The incidence of ocular adverse events in the study eye was similar across groups (aflibercept 8q12 n=129 [39%]; aflibercept 8q16 n=127 [38%]; and aflibercept 2q8 n=130 [39%]).

INTERPRETATION

Aflibercept 8 mg showed efficacy and safety with extended dosing intervals, which has the potential to improve the management of patients with nAMD.

FUNDING

Bayer AG and Regeneron Pharmaceuticals.

Ocular, Visual, and Anatomical Outcomes in Eyes Requiring Incisional Intraocular Pressure-Lowering Surgery Following the 0.19-mg Fluocinolone Acetonide Intravitreal Implant

BACKGROUND AND OBJECTIVE

To assess ocular, visual, and anatomical outcomes following the 0.19-mg fluocinolone acetonide (FAc) intravitreal implant (ILUVIEN®) and incisional intraocular pressure (IOP)-lowering surgery in diabetic macular edema.

PATIENTS AND METHODS

From a 36-month, phase 4, open-label, observational study (N = 202 eyes, 159 patients), 8 eyes (7 patients) required IOP-lowering surgery post-FAc; eyes were segregated by FAc-induced (n = 5, 2.47%) versus neovascular glaucoma (NVG)-related (n = 3, 1.49%) IOP elevations and assessed for IOP, best corrected visual acuity (BCVA), central subfield thickness (CST), and cup-to-disc ratio (c/d).

RESULTS

Changes at 36 months were +5.4 letters BCVA (P > 0.05) and +0.09 c/d (P = 0.0217); IOP and CST were unchanged. FAc-induced-group eyes required fewer IOP-lowering medications than NVG-group eyes (2.0 versus 4.0; P < 0.01) but for longer duration (15.2 versus 2.6 months; P < 0.001).

CONCLUSIONS

Post-FAc IOP-lowering surgery, regardless of cause, largely did not affect the outcomes measured; these procedures, then, may not meaningfully threaten positive outcomes. [Ophthalmic Surg Lasers Imaging Retina 2024;55:22-29.].

The 0.19-mg Fluocinolone Acetonide Intravitreal Implant for Diabetic Macular Edema: Intraocular Pressure-Related Effects over 36 Months

PURPOSE

To evaluate effects of the 0.19-mg fluocinolone acetonide (FAc) intravitreal implant (ILUVIEN) on intraocular pressure (IOP) in patients with diabetic macular edema (DME).

DESIGN

Secondary analysis of a 36-month, phase IV, nonrandomized, open-label, observational study.

PARTICIPANTS

The study included 202 eyes from 159 patients who received the 0.19-mg FAc implant after a successful prior steroid challenge per the United States label indication.

METHODS

Study eyes were assessed for IOP values, incidence of IOP elevations, and best-corrected visual acuity (BCVA) for up to 36 months post-FAc implant.

RESULTS

Mean IOP was stable over 36 months post-FAc; IOP change from baseline peaked at 2.12 mmHg at 9 months, then declined to baseline levels. At 36 months, eyes had a 32.5% cumulative probability of an IOP event > 25 mmHg and a 15.6% probability of an IOP event > 30 mmHg (Kaplan-Meier). The probability of requiring IOP-lowering medication at any time by month 36 was 38.3%. A total of 78% of eyes did not have IOP elevations > 25 mmHg if similar values were seen with the previous steroid challenge. Although 7.4% of eyes had an IOP > 30 mmHg during a scheduled study visit, most exceeded this threshold only once (60%). Regardless of IOP status, mean BCVA remained stable.

CONCLUSIONS

Over 36 months, the 0.19-mg FAc implant was associated with relatively stable IOPs in patients with DME, and there was no significant impact of IOP elevations identified regarding their effects on long-term visual outcomes. The probability that a prior corticosteroid challenge will not predict an IOP elevation > 25 mmHg over 36 months post-FAc is 22%; therefore, routine IOP monitoring should be scheduled.

FINANCIAL DISCLOSURE(S)

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

Avacincaptad pegol for geographic atrophy secondary to age-related macular degeneration: 18-month findings from the GATHER1 trial

BACKGROUND/OBJECTIVES

To assess the safety and efficacy of avacincaptad pegol (ACP), a C5 inhibitor, for geographic atrophy (GA) secondary to age-related macular degeneration (AMD) over an 18-month treatment course.

SUBJECTS/METHODS

This study was an international, prospective, randomized, double-masked, sham-controlled, phase 2/3 clinical trial that consisted of 2 parts. In part 1, 77 participants were randomized 1:1:1 to receive monthly intravitreal injections of ACP 1 mg, ACP 2 mg, or sham. In part 2, 209 participants were randomized 1:2:2 to receive monthly ACP 2 mg, ACP 4 mg, or sham. The mean rate of change of GA over 18 months was measured by fundus autofluorescence.

RESULTS

Compared with their respective sham cohorts, monthly ACP treatment reduced the mean GA growth (square root transformation) over 18 months by 28.1% (0.168 mm, 95% CI [0.066, 0.271]) for the 2 mg cohort and 30.0% (0.167 mm, 95% CI [0.062, 0.273]) for the 4 mg cohort. ACP treatment was generally well tolerated over 18 months, with most ocular adverse events (AEs) related to the injection procedure. Macular neovascularization (MNV) was more frequent in both 2 mg (11.9%) and 4 mg (15.7%) cohorts than their respective sham control groups (2.7% and 2.4%).

CONCLUSIONS

Over this 18-month study, ACP 2 mg and 4 mg showed continued reductions in the progression of GA growth compared to sham and continued to be generally well tolerated. A pivotal phase 3 GATHER2 trial is currently underway to support the efficacy and safety of ACP as a potential treatment for GA.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Randomized Phase 2b Study of Brimonidine Drug Delivery System Generation 2 for Geographic Atrophy in Age-related Macular Degeneration

PURPOSE

To evaluate the safety and efficacy of repeat injections of Brimonidine Drug Delivery System (Brimo DDS) Generation 2 (Gen 2) containing 400 μg brimonidine in patients with geographic atrophy (GA) secondary to age-related macular degeneration (AMD).

DESIGN

Phase 2b, randomized, multicenter, double-masked, sham-controlled, 30-month study (BEACON).

PARTICIPANTS

Patients diagnosed with GA secondary to AMD and multifocal lesions with total area >1.25 mm² and ≤18 mm² in the study eye.

METHODS

Enrolled patients were randomized to treatment with intravitreal injections of 400-μg Brimo DDS (n=154) or sham procedure (n=156) in the study eye every 3 months from day 1 through month 21.

MAIN OUTCOME MEASURES

The primary efficacy endpoint was change from baseline in the GA lesion area in the study eye, assessed with fundus autofluorescence imaging, at month 24. Safety measures included treatment-emergent adverse events (AEs).

RESULTS

The study was terminated early, at the time of the planned interim analysis, because of a slow GA progression rate (∼1.6 mm²/year) in the enrolled population. Least-squares mean (standard error) GA area change from baseline at month 24 (primary endpoint) was 3.24 (0.13) mm² with Brimo DDS (n=84) versus 3.48 (0.13) mm² with sham (n=91); the reduction in GA area change from baseline in the Brimo DDS group compared with the sham group was 0.25 mm² (7%) (P = 0.150). At month 30, the GA area change from baseline was 4.09 (0.15) mm² with Brimo DDS (n=49) versus 4.52 (0.15) mm² with sham (n=46), a reduction of 0.43 mm² (10%) with Brimo DDS compared with sham (P=0.033). Exploratory analysis showed numerically smaller loss over time in retinal sensitivity assessed with scotopic microperimetry with Brimo DDS compared with sham (P=0.053 at month 24). Treatment-related AEs were usually related to the injection procedure. No implant accumulation was observed.

CONCLUSIONS

Multiple intravitreal administrations of Brimo DDS (Gen 2) were well tolerated. The primary efficacy endpoint at 24 months was not met, but there was a numerical trend for reduction in GA progression at 24 months compared with sham treatment. The study was terminated early because of the lower-than-expected GA progression rate in the sham/control group.

Impact of Modifying Abicipar Manufacturing Process in Patients with Neovascular Age-Related Macular Degeneration: MAPLE Study Results

Purpose

To evaluate the impact of modifying the abicipar pegol (abicipar) manufacturing process on the safety and treatment effect of abicipar in patients with neovascular age-related macular degeneration (nAMD).

Methods

A new process for manufacturing abicipar was developed to reduce host cell impurities. In a prospective, Phase 2, multicenter, open-label, 28-week clinical trial, patients (n=123) with active nAMD received intravitreal injections of abicipar 2 mg at baseline (day 1) and weeks 4, 8, 16, and 24. Outcome measures included proportion of patients with stable vision (<15-letter loss from baseline; primary endpoint), change from baseline in best-corrected visual acuity (BCVA) and central retinal thickness (CRT), and adverse events.

Results

Overall, 8.9% (11/123) of patients experienced intraocular inflammation (IOI) and discontinued treatment. IOI cases were assessed as mild (2.4% [3/123]), moderate (4.9% [6/123]), or severe (1.6% [2/123]) and resolved with steroid treatment. Visual acuity in most patients with IOI (8 of 11) recovered to baseline BCVA or better by study end. No cases of endophthalmitis or retinal vasculitis were reported. Stable vision was maintained for ≥95.9% (≥118/123) of patients at all study visits. At week 28, treatment-naïve patients showed a greater mean improvement from baseline in BCVA compared with previously treated patients (4.4 vs 1.8 letters) and a larger mean CRT reduction from baseline (98.5 vs 45.5 μm).

Conclusion

Abicipar produced using a modified manufacturing process showed a moderately lower incidence and severity of IOI compared with Phase 3 abicipar studies. Beneficial effects of treatment were demonstrated.

Impact of retinal fluid-free months on outcomes in nAMD: a treatment agnostic analysis of the HAWK and HARRIER studies

PURPOSE

To assess the effect of the total number of fluid-free months after loading on visual and anatomical outcomes in neovascular age-related macular degeneration (nAMD) patients receiving anti-vascular endothelial growth factor (anti-VEGF) therapy.

METHODS

This post-hoc analysis pooled patient-level data from the brolucizumab 6 mg (n=718) and aflibercept 2 mg (n=715) arms of the HAWK and HARRIER randomized clinical trials. Based on data from Weeks 12 to 96, patients were assigned to one of 5 categories based on fluid-free visits (FFV; the total number of monthly visits at which they were observed to be without retinal fluid). Three definitions of 'fluid-free' were explored based on the location of the fluid observed.

RESULTS

Patients allocated to categories 4 (15-21 FFV) and 5 (22 FFV, always dry) consistently had the best visual and anatomical outcomes at Week 96, while patients allocated to categories 1 (0 FFV, never dry) and 2 (1-7 FFV) consistently had the worst visual and anatomical outcomes. Variability in retinal thickness over time was lowest in categories 4 and 5.

CONCLUSION

Absence of retinal fluid at more visits after loading has a positive association with visual and anatomic outcomes in nAMD patients, regardless of fluid type.

Inhibition of Complement Factor 3 in Geographic Atrophy with NGM621: Phase 1 Dose-Escalation Study Results

PURPOSE

To evaluate the safety and tolerability of single and multiple intravitreal injections of NGM621 in patients with geographic atrophy (GA) and to characterize the pharmacokinetics and immunogenic potential.

DESIGN

Multicenter, open-label, single- and multiple-dose phase 1 study.

METHODS

Fifteen patients enrolled at 4 sites in the United States. Participants had GA secondary to age-related macular degeneration, lesion size ≥2.5 mm², best-corrected visual acuity of 4 to 54 letters (20/80 to 20/800 Snellen equivalent) in the study eye, and no history of choroidal neovascularization in either eye. Patients who met eligibility criteria were treated in a single ascending-dose phase (2 mg, 7.5 mg, and 15 mg) or received 2 doses of NGM621 (15 mg) 4 weeks apart in the multidose phase and were monitored for 12 weeks (85 days). Assessments included adverse events, best-corrected visual acuity, low-luminance visual acuity, vital signs, clinical laboratory evaluations, GA lesion area as measured by fundus autofluorescence, spectral domain optical coherence tomography, and pharmacokinetic, immunogenicity, and pharmacodynamic assessments.

RESULTS

All 15 participants completed the 12-week study. There were no serious adverse events, no drug-related adverse events, and no choroidal neovascularization developed in either eye. Mean visual acuity and GA lesion area appeared stable through week 12 for all cohorts. Pharmacokinetic analyses indicated that NGM621 serum exposures appeared to be dose proportional, and no antidrug antibodies were identified at any of the evaluated time points.

CONCLUSIONS

In this small, open-labeled, 12-week phase 1 study, NGM621 was safe and tolerable when administered intravitreally up to 15 mg.<END ABSTRACT>.

Home Monitoring of Age-Related Macular Degeneration: Utility of the ForeseeHome Device for Detection of Neovascularization

PURPOSE

To evaluate the real-world utility of the ForeseeHome monitoring device (Notal Vision, Ltd., Tel Aviv, Israel) for the detection of conversion from intermediate age-related macular degeneration (iAMD) to neovascular AMD (nAMD) and to compare with results published by the Home Monitoring of the Eye (HOME) study.

DESIGN

Retrospective analysis of electronic health records.

PARTICIPANTS

Eyes prescribed use of the ForeseeHome device across 4 retinal practices in the United States.

METHODS

Usage information was collected from the online ForeseeHome portal for all eyes prescribed the device. For a predetermined subset of eyes, additional clinical information was collected through chart review and analyzed for clinical utility.

MAIN OUTCOME MEASURES

Frequency and length of use, number of eyes that used the device, number of eyes that established a baseline measurement, number of eyes that converted to nAMD, and number of alerts.

RESULTS

Seven hundred seventy-five eyes of 448 patients were prescribed use of the ForeseeHome device. Six hundred forty-nine eyes (83.7%) used the device at least once; among this population, 478 (73.7%) established a baseline measurement. Patients who established a baseline measurement were significantly younger than those who did not (P < 0.001). Among eyes that established a baseline measurement, 126 (26.4%) had an overall inadequate frequency of use (≥2 tests per week), and 250 (52.3%) did not use the device as frequently as instructed by the manufacturer (≥3 tests per week); 24.7% of eyes discontinued use within 1 year. Of the 136 eyes that established a baseline measurement among 211 eyes prescribed the device at 1 clinical site, 52 alerts were recorded; 3 (6.8%) correctly identified conversion to nAMD and 47 (93.2%) represented false-positive alerts.

CONCLUSIONS

Compared with the prospective HOME study, the utility of the ForeseeHome device in the current analysis of clinical practice application was limited. A meaningful proportion of eyes never used the device or could not establish a baseline measurement. Overall frequency of use was low, and continuous use of the device decreased over time. A need exists for improvement in home monitoring technology for eyes with iAMD at risk of conversion to nAMD.

Two-year interim safety results of the 0.2 µg/day fluocinolone acetonide intravitreal implant for the treatment of diabetic macular oedema: the observational PALADIN study

Background

The 0.2 µg/day fluocinolone acetonide (FAc) implant delivers continuous, low-dose, intravitreal corticosteroid for the treatment of diabetic macular oedema (DMO). This ongoing, 3-year, observational clinical trial provides long-term, ‘real-world’ safety results for the FAc implant in DMO.

Methods

This 24-month interim analysis of a prospective, observational study investigated patients with DMO receiving the commercially available intravitreal 0.2 µg/day FAc implant. The primary outcome was incidence of intraocular pressure (IOP)-lowering procedures. Other IOP-related signals and their relationship to previous corticosteroid exposure, best-corrected visual acuity, central subfield thickness (CST), ocular adverse events and frequency of other treatments were also measured.

Results

Data were collected from 95 previously steroid-challenged patients (115 study eyes) for up to 36 months pre-FAc and 24 months post-FAc implant. Mean IOP for the overall population remained stable post-FAc compared with pre-FAc implant. IOP-related procedures remained infrequent (two IOP-lowering surgeries pre-FAc; two trabeculoplasties and four IOP-lowering surgeries post-FAc). Mean visual acuity was stable post-FAc (mean improvement of 1–3 letters) and fewer DMO treatments were required per year following FAc implant. Mean CST was significantly reduced at 24 months post-FAc implant (p<0.001) and the percentage of patients with CST ≤300 µm was significantly increased (p=0.041).

Conclusion

Few IOP-related procedures were reported during the 24 months post-FAc implant. Positive efficacy outcomes were noted after treatment, with stabilisation of vision and reduction in inflammation, demonstrated by CST. The FAc implant has a favourable benefit–risk profile in the management of DMO, especially when administered after a prior steroid challenge.

Trial registration number

NCT02424019.

A novel pancreatic model: the snip method of pancreatic isolation for in vitro study

We aimed to devise a method of preparing the pancreas for in vitro study that would provide tissue that is viable and functional for 24 h, with preservation of integral functional cell-membrane structures. Pancreata of NIH Swiss mice were excised, gently insufflated with media, and carefully snipped into portions of < 0.5 mm. Snips were incubated in cell culture for 0, 8, 24, and 48 h, with viability measured by 3-[4,5-dimethylthiazol-2-yl]-2,3-diphenyltetrazolium bromide (MTT) assay and amylase production quantified after stimulation with cerulein. Recombinant tumor necrosis factor-alpha (TNF-alpha) was added to cell culture, and apoptosis demonstrated by Hoechst staining at 0, 24, and 48 h. At 0, 8, and 24 h, pancreatic snips were determined to be viable by MTT assay. They also were functional with intact cell-membrane apparatuses at these same time points, as evidenced by amylase production in response to a cholecystokinin analogue. We were able to induce apoptosis with TNF-alpha ligand in these pancreatic snips in support of viability and overall cellular function. We conclude that the snip method provides an effective in vitro pancreatic model. Acinar cells are viable and functional for > or = 24 h, with evidence that their cell-surface receptors are preserved in their operational state.

Bimanual, bipolar intraocular diathermy

We performed bimanual, bipolar intraocular diathermy by using a No. 22 disposable needle and a vitrectomy instrument. The technique required a smaller wound than unimanual bipolar cautery and was combined with membrane peeling techniques. The bipolar technique limited the extent of coagulation effects better than unipolar diathermy methods.

A chin-operated switch for motorized three-axis microscopic movement

A chin-operated switch was developed to permit control of motorized operating microscope movement simultaneously along three axes. It permits use of both feet to operate surgical modalities, decreases microscope positioning time, and decreases needless hand movements.

Mechanical syringe drive for vitreous surgery

A mechanical syringe drive permits one-handed, precise control of the suction force at the time of vitrectomy, is autoclavable, utilizes disposable syringes, and can be operated by surgeon or assistant.