One year outcomes of treat and extend and pro re nata (PRN) treatment regimens with aflibercept for polypoidal choroidal vasculopathy

Anti-Vascular Endothelial Growth Factor Therapy Regimens for Polypoidal Choroidal Vasculopathy: A Systematic Review

INTRODUCTION

There are no guidelines on the optimal anti-vascular endothelial growth factor (anti-VEGF) monotherapy regimen for patients with polypoidal choroidal vasculopathy (PCV). In this study, we aimed to assess the comparative safety and efficacy of different treatment regimens of anti-VEGF monotherapy for PCV.

METHODS

We conducted a systematic literature search on Ovid MEDLINE, Embase, and Cochrane Library from January 2000 to May 2023 for comparative articles reporting on different treatment regimens of anti-VEGF agents in PCV. Our primary outcomes were the final best-corrected visual acuity (BCVA) and the change in BCVA from baseline. Secondary outcomes were the final retinal thickness (RT), the change in RT from baseline, the rate of polyp closure, and the incidence of adverse events.

RESULTS

A total of 10,440 studies were screened, and seven studies reporting on 636 eyes with PCV at baseline were included in this systematic review. One RCT of 53 eyes found a similar final BCVA, change in BCVA from baseline, final RT, and complete polyp closure rate between a treat-and-extend (T&E) regimen and a bimonthly fixed-dosing regimen of aflibercept. This trial also found superiority of T&E for change in RT from baseline. One observational study of 33 eyes found a similar BCVA at last study observation between a pro re nata (PRN) regimen and bimonthly fixed-dosing regimen of aflibercept. One observational study of 42 eyes found a similar change in BCVA from baseline and complete polyp closure rate between a PRN regimen and bimonthly fixed-dosing regimen of aflibercept. One RCT of 249 eyes found a similar change in BCVA and RT from baseline, as well as polyp closure, between a T&E regimen and fixed 12-week dosing regimen of conbercept. One observational study of 30 eyes found a superiority of T&E aflibercept for change in BCVA and risk of polyp recurrence, compared to a PRN regimen.

CONCLUSION

Overall, there is a paucity of evidence comparing various treatment regimens of anti-VEGF therapy in patients with PCV. This limited evidence suggests that current treatment regimens are similarly efficacious, though T&E aflibercept achieved superior outcomes when compared to bimonthly dosing or PRN in some individual studies. Further trials are needed to confirm or refute these findings.

The comparison of two different strategies of intravitreal conbercept for polypoidal choroidal vasculopathy in Chinese patients results from a 48-week randomized phase 4 study: STAR study

PURPOSE

To compare a treat-and-extend (TAE) strategy with a fixed dosing regimen of intravitreal conbercept (IVC) for the management of treatment-naïve polypoidal choroidal vasculopathy (PCV) patients.

METHODS

249 patients with treatment-naïve PCV were randomized 1:1 to fixed dosing regimen with injections every 12 weeks (3 + Q12W) group or treat-and-extend regimen(3 + TAE) group. Patients received 3 monthly intravitreal injections of 0.5 mg conbercept as loading dose in both groups. The 3 + Q12W patients were monitored monthly and received mandated injections every 12 weeks; the 3 + TAE patients were monitored and treated monthly until the resolution of exudative disease activity; the interval between visits was then individualized according to study protocol. Visual and anatomical outcomes were compared between the two groups.

RESULTS

At 48 weeks, there was no significant difference between the 3 + Q12W group and 3 + TAE group in mean BCVA improvement (p = 0.421), mean changes in central retinal thickness (CRT) (p = 0.818), maximum retinal thickness (MRT) (p = 0.448), pigment epithelial detachment (PED) height (p = 0.221), PED volume (p = 0.076), branching vascular network (BVN) area (p = 0.615), polypoidal lesion number (p = 0.701), polypoidal lesion area (p = 0.424), rates of patients who avoided vision loss of ≥15 ETDRS letters (p = 0.397) or complete polypoidal lesion regression rate (43.8% vs. 41.8%, p = 0.814). The 3 + Q12W group had more decreased retinal haemorrhage area (p = 0.014) and fewer mean numbers of injections comparing with 3 + TAE group (6.6 vs. 9.4, p < 0.001). Mean maximum extension interval between injections after loading injections was 9.6 ± 2.0 weeks for 3 + TAE group, with 27.8% of patients achieving an extension interval of 12 weeks and 61.1% patients 8 weeks or more.

CONCLUSIONS

Both 3 + Q12W and 3 + TAE regimens of IVC could result in improvement in visual and anatomical outcomes in PCV patients.

Updated guidelines for the management of polypoidal choroidal vasculopathy: Recommendations from the Indian Polypoidal Choroidal Vasculopathy Panel and the Vitreoretinal Society of India

In Asians, polypoidal choroidal vasculopathy (PCV) is becoming more widely recognized as a significant cause of exudative maculopathy. The previous set of Indian guidelines on the management of PCV were published in 2018, with a literature search updated up to November 2015. As the treatment of PCV evolves, retinal physicians must constantly modify their current practice. The current guidelines are based on the most up-to-date information on PCV and are an update to the previous set of guidelines. These guidelines were developed by a panel of Indian retinal experts under the aegis of the Vitreoretinal Society of India (VRSI), based on a comprehensive search and assessment of literature up to September 2021. The final guidelines i) provide the updated nomenclature in PCV; ii) discusses the newer diagnostic imaging features of PCV, especially in the absence of indocyanine green angiography (ICGA); and iii) recommends the best possible therapeutic approach in the management of PCV, including the choice of anti-vascular endothelial growth factor (anti-VEGF) agents, treatment regimen, and the role of switching between the anti-VEGF agents. In the face of non-availability of photodynamic therapy (PDT) in India, we constructed practical recommendations on anti-VEGF monotherapy in PCV. The current updated recommendations would provide a broader framework to the treating retinal physician for the diagnosis and management of PCV for optimal therapeutic outcomes.

Evolving treatment paradigms for PCV

Polypoidal choroidal vasculopathy (PCV) is a subtype of neovascular AMD (nAMD) that accounts for a significant proportion of nAMD cases worldwide, and particularly in Asia. Contemporary PCV treatment strategies have closely followed those used in typical nAMD, though there are significant gaps in knowledge on PCV management and it remains unclear if these strategies are appropriate. Current clinical trial data suggest intravitreal anti-vascular endothelial growth factor (VEGF) therapy alone or in combination with photodynamic therapy is effective in managing haemorrhage and exudation in PCV, although the optimal treatment interval, including as-needed and treat-and-extend approaches, is unclear. Newer imaging modalities, including OCT angiography and high-resolution spectral domain OCT have enabled characterisation of unique PCV biomarkers that may provide guidance on how and when treatment and re-treatment should be initiated. Treatment burden for PCV is a major focus of future therapeutic research and several newly developed anti-VEGF agents, including brolucizumab, faricimab, and new modes of drug delivery like the port delivery system, offer hope for dramatically reduced treatment burden for PCV patients. Beyond anti-VEGF therapy, recent developments in our understanding of PCV pathophysiology, in particular the role of choroidal anatomy and lipid mediators in PCV pathogenesis, offer new treatment avenues that may become clinically relevant in the future. This article explores the current management of PCV and more recent approaches to PCV treatment based on an improved understanding of this unique disease process.