Understanding Retinal Vasculitis Associated with Brolucizumab: Complex Pathophysiology or Occam's Razor?

Intra-Ocular Inflammation and Occlusive Retinal Vasculitis Following Intravitreal Injections of Faricimab: A Case Report

PURPOSE

Faricimab is a bispecific antibody that inhibits angiopoietin-2 and vascular endothelial growth factor-A action and has been approved for the treatment of neovascular age-related macular degeneration and diabetic macular edema. Clinical trials have demonstrated its favorable safety profile. This report presents a case of intra-ocular inflammation and occlusive retinal vasculitis following a second intravitreal injection of faricimab.

METHODS

A single case report was obtained from a tertiary referral center.

RESULTS

A 73-year-old Asian man diagnosed with polypoidal choroidal vasculopathy presented with decreased vision in the left eye (OS) 2 weeks after the second faricimab administration. In the fourth week after the second faricimab injection, swept-source optical coherence tomography (OCT) revealed hyperreflective dots in the vitreous cavity, indicating vitreous cells. Color fundus photography showed new-onset perivenular hemorrhages and pallor of the inferonasal retina OS, of which OCT revealed retinal inner layer thickening, suggestive of retinal arteriolar occlusions. Retinal fluorescein angiography revealed delayed filling of the inferior temporal vein. The patient was diagnosed with intraocular inflammation and occlusive retinal vasculitis OS associated with repeated intravitreal faricimab administrations. Intravitreal dexamethasone implant was used instead of faricimab at this visit.

CONCLUSIONS

The findings of this case hint towards the potential risk of retinal occlusive events associated with intravitreal faricimab injections.

Comparison between intravitreal brolucizumab and aflibercept in the treatment-naive central involved diabetic macular edema: One-year real-life case series

PURPOSE

To evaluate the effectiveness and safety of intravitreal brolucizumab (IVB) and intravitreal aflibercept (IVA) injections in the management of naive central involved diabetic macular edema (CIDME).

METHODS

This study included 45 treatment-naive eyes with CIDME. A complete ophthalmic examination, including BCVA and SD-OCT was performed. Patients were randomized to (IVB) or (IVA) groups. All participants received a loading phase of three consecutive intravitreal injections, then followed by a personalized treat and extend (T&E) regimen.

RESULTS

At 12-month follow-up, the mean numbers of injections in IVA and IVB groups were 7.25  ±  0.53 and 6.3  ±  0.45, respectively (P < 0.0001). The IVA group showed a significant increase of the mean BCVA from 0.66  ±  0.15 logMAR (50.9  ±  7.7 letters) to 0.41  ±  0.19 logMAR (63.7  ±  10.8 letters). Mean CFT decreased significantly from 441.2  ±  35.7 μm to 281.3  ±  18.4 μm. The IVB group showed a significant increase of mean BCVA from 0.65  ±  0.16 logMAR (52.1  ±  7.9 letters) to 0.39  ±  0.17 logMAR (65.3  ±  8.7 letters). Mean CFT decreased significantly from 437.2  ±  41.9 μm to 275.5  ±  21.7 μm.No significant difference between both groups in terms of the vision improvement and the reduction of CFT was reported, whereas a statistical difference was observed in terms of intravitreal injections (IVI) numbers. No ocular complications were reported.

CONCLUSIONS

This case series highlights the effectiveness of both brolucizumab and aflibercept in the treatment of CIDME with a lower frequency of injection in brolucizumab group lowering the burden of IVI in this cohort.

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

Purpose

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

Methods

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

Results

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

Conclusions

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

Differential diagnosis of endophthalmitis after intravitreal drug injection for age related macular degeneration: Sterile vs. infectious

The recent release of brolucizumab and the development of new antiangiogenic molecules as abicipar pegol has increased the interest towards inflammatory complications after intravitreal drug injection. Those drugs are associated to a higher rate of inflammatory adverse events compared to classic drugs. In this context it is essential to differentiate between sterile and infectious cases for a fast and effective treatment. The clinical similarities between infectious and sterile cases, the high rate of culture negative patients and the heterogeneity in the terminology used are obstacles for a correct diagnosis and report of these complications. Sterile cases appear early after the injection, before 48 hours; or 20 days after in brolucizumab-related vasculitis cases. Infectious cases show up around the third day after injection and up to a week after it. A severe visual impairment, severe pain, severe hyperemia, hypopyon and a more severe intraocular inflammatory process are signs of a likely infectious origin. If the cause of the inflammation is uncertain we must follow up the patient closely or "tap and inject" antimicrobial agents in order to prevent the eventual complications of an infectious endophthalmitis. On the other hand, sterile endophthalmitis might be observed in mild cases or treated with steroids according to the severity of the inflammation.

Review on the Safety and Efficacy of Brolucizumab for Neovascular Age-Related Macular Degeneration From Major Studies and Real-World Data

Frequent antivascular endothelial growth factor injections in neovascular age-related macular degeneration (nAMD) often lead to poor compliance and suboptimal outcomes. A longer-acting agent has been a pressing unmet need until recently. Brolucizumab, an antivascular endothelial growth factor agent, is a single-chain antibody fragment approved by the US Food and Drug Administration (FDA) on October 8, 2019, for treating nAMD. It delivers more molecules at equivalent volumes of aflibercept, thus achieving a longer-lasting effect. We reviewed literature published in English between January 2016 and October 2022 from MEDLINE, PubMed, Cochrane database, Embase, and Google scholar using the keywords: "Brolucizumab, real-world data, intraocular inflammation (IOI), safety, and efficacy". Brolucizumab showed reduced injection frequency, better anatomic outcomes, and noninferior vision gains compared with aflibercept in HAWK and HARRIER studies. However, post hoc studies on brolucizumab revealed a higher-than-expected incidence of IOI, leading to the early termination of 3 studies: MERLIN, RAPTOR, and RAVEN for nAMD, branch retinal vein occlusion, and central retinal vein occlusion, respectively. Contrastingly real-world data showed encouraging outcomes in terms of fewer IOI cases. The subsequent amendment of the treatment protocol resulted in reduced IOI. Thereafter US FDA approved its use in diabetic macular edema on June 1, 2022. Based on major studies and real-world data, this review shows that brolucizumab is effective for treating naive and refractory nAMD. The risk of IOI is acceptable and manageable, but proper preinjection screening and high-vigilance care of IOI are needed. More studies are warranted to evaluate further the incidence, best prevention, and treatment measures for IOI.

Beovu, but not Lucentis impairs the function of the barrier formed by retinal endothelial cells in vitro

Because rare, but severe adverse effects, i.e. retinal vasculitis or retinal vein occlusion, have been observed after repetitive intravitreal injections of VEGF-A-binding single-chain variable fragment brolucizumab (Beovu), we investigated its possible impact on the barrier formed by immortalized bovine retinal endothelial cells (iBREC) in comparison to that of the VEGF-A-binding Fab fragment ranibizumab (Lucentis). As a measure of stability of the barrier formed by a confluent monolayer of iBREC, we determined the cell index over seven days by continuous electric cell-substrate impedance measurements: Beovu but not Lucentis indeed significantly lowered the cell index, evident about 1.5 days after its addition, pointing to barrier impairment. Early after addition of Beovu, amounts of the integrins α5 and β1-subunits of the fibronectin receptor-had changed in opposite ways, suggesting an effect on cell adhesion due to hindered dimer formation. After exposure for eight days to Beovu, levels of claudin-1-an essential part of the iBREC barrier-were significantly lower, less claudin-1 was located at the plasma membrane after exposure to the VEGF-A antagonist for five days. Beovu did not induce secretion of inflammatory cytokines or VEGF-A. Interestingly, polysorbate-80-component of Beovu-but not polysorbate-20-in Lucentis-slightly, but significantly lowered the cell index, also associated with reduced claudin-1 expression. In summary, our results indicate that Beovu changes the behavior of retinal endothelial cells, thus providing an alternative "non-immunological" explanation for the most relevant of observed side effects.

One-year results of treat-and-extend regimen with intravitreal brolucizumab for treatment-naïve neovascular age-related macular degeneration with type 1 macular neovascularization

We evaluated 1-year outcomes of loading phase treatment followed by maintenance treatment using a treat-and-extend (TAE) regimen with intravitreal brolucizumab for neovascular age-related macular degeneration (nAMD) associated with type 1 macular neovascularization (MNV). We analyzed 68 eyes of 65 consecutive patients with treatment-naïve nAMD associated with type 1 MNV. Forty-five eyes (66.2%) completed the 1-year treatment with intravitreal brolucizumab. In those cases, best-corrected visual acuity (BCVA) showed significant improvement, while there were significant reductions in foveal thickness and central choroidal thickness, after the initial brolucizumab injection, which were maintained until the last visit. The average total number of injections over 1 year was 6.4 ± 0.6. The average intended injection interval at the last visit was 14.0 ± 2.9 weeks. Moreover, 17of 23 eyes (73.9%) with polypoidal lesions showed complete regression of these lesions after the loading phase treatment. Although intraocular inflammation (IOI) was observed in 15 of 68 eyes (22.1%) within 1 year, amelioration in response to combination therapy with topical and subtenon injection of steroids, without visual decline, was obtained. These results indicate that loading phase treatment followed by the TAE regimen with intravitreal brolucizumab might improve BCVA and ameliorate exudative changes in eyes with treatment-naïve nAMD associated with type 1 MNV. Moreover, intravitreal brolucizumab can potentially reduce the treatment burden of nAMD. Prompt steroid therapy might be efficacious for ameliorating brolucizumab-related IOI without visual decline.

Initial Pro Re Nata Brolucizumab for Exudative AMD: The PROBE Study

The present study aimed to determine the efficacy and safety of pro re nata (PRN) intravitreal brolucizumab therapy for neovascular age-related macular degeneration (AMD) without a loading dose in the real-world setting. The PROBE study (Pro Re Nata Brolucizumab for Exudative AMD) is a retrospective, observational, multicentric study that included 27 treatment-naïve patients (27 eyes) with neovascular AMD who received PRN brolucizumab therapy with the treatment interval being at least 8 weeks, should the need for a second consecutive injection arise. The primary outcome measure was changed to best-corrected visual acuity (BCVA) over time. Secondary outcome measures included the determination of change in central subfield thickness (CST) and complications. The mean follow-up was 11.2 ± 1.2 months. The mean baseline and final BCVA were 57.4 ± 4.5 letters and 65.3 ± 3.12 letters, respectively (p = 0.014). The mean gain in letters at the end of follow-up was 7.8 ± 3.5 letters. There was a significant decrease in CST at the end of the follow-up period (p = 0.013). Patients received a mean of 2.2 ± 0.9 injections (in addition to the first mandatory injection) during the follow-up period. There were no adverse events noted. In conclusion, initial PRN brolucizumab for exudative AMD without a loading dose demonstrated significant visual improvement and no adverse events.