Cost-effectiveness of Aflibercept Monotherapy vs Bevacizumab First Followed by Aflibercept If Needed for Diabetic Macular Edema

Bilateral improvement in age-related macular degeneration following unilateral Aflibercept injection

BACKGROUND

The "fellow-eye effect" in anti-vascular endothelial growth factor (anti-VEGF) therapy is a rare phenomenon, particularly with aflibercept. This case report documents the first instance of this effect in Pakistan, highlighting its significance in a resource-limited setting where recent regulatory changes have restricted treatment options for age-related macular degeneration (AMD).

CASE PRESENTATION

A 62-year-old male presented with bilateral central vision loss due to neovascular AMD. Optical Coherence Tomography revealed serous subretinal fluid in both eyes. Due to financial constraints, only the right eye received a single 2 mg intravitreal aflibercept injection. Remarkably, at the four-week follow-up, both eyes showed significant improvement. Visual acuity improved from 6/12 to 6/9 in the treated right eye and from 6/15 to 6/12 in the untreated left eye. OCT scans demonstrated bilateral resorption of subretinal fluid. At three months, complete fluid resorption was observed in both eyes, with visual acuity improving to 6/6 bilaterally.

CONCLUSIONS

This case underscores the potential of the "fellow-eye effect" in anti-VEGF therapy, particularly with aflibercept, in treating bilateral AMD. It highlights a possible strategy for optimizing treatment regimens and reducing costs in resource-limited settings. However, it also raises concerns about systemic absorption and potential risks. The findings emphasize the need for further research on the pharmacokinetics of anti-VEGF agents, personalized treatment plans, and alternative therapies. This case is particularly significant in the context of Pakistan's recent ban on bevacizumab, underscoring the urgent need for accessible and affordable AMD treatments in developing countries.

Cost-effectiveness Analysis of Ranibizumab Biosimilar for Neovascular Age-Related Macular Degeneration and its Subtypes from the Societal and Patient Perspectives in Japan

INTRODUCTION

This study evaluated the cost-effectiveness of anti-vascular endothelial growth factor (VEGF) therapies for subtypes of neovascular age-related macular degeneration (nAMD) from the societal perspective, and for any nAMD from the patient perspective in Japan.

METHODS

A Markov model was developed to simulate the lifetime transitions of a cohort of patients with nAMD through various health states based on the involvement of nAMD, the treatment status, and decimal best-corrected visual acuity. Ranibizumab biosimilar was compared with aflibercept from the societal perspective regardless of treatment regimen for the analysis of three subtypes (typical nAMD, polypoidal choroidal vasculopathy (PCV), and retinal angiomatous proliferation (RAP)). Two analyses from the patient perspective focusing on the treat-and-extend regimens were performed, one with a cap on patients' copayments and one without. Ranibizumab biosimilar was compared with branded ranibizumab, aflibercept, aflibercept as the loading dose switching to ranibizumab biosimilar during maintenance (aflibercept switching to ranibizumab biosimilar), and best supportive care (BSC), for patients with any nAMD.

RESULTS

In the subtype analyses, ranibizumab biosimilar when compared with aflibercept resulted in incremental quality-adjusted life years (QALYs) of - 0.015, 0.026, and 0.009, and the incremental costs of Japanese yen (JPY) - 50,447, JPY - 997,243, and JPY - 1,286,570 for typical nAMD, PCV, and RAP, respectively. From the patient perspective, ranibizumab biosimilar had incremental QALYs of 0.015, 0.009, and 0.307, compared with aflibercept, aflibercept switching to ranibizumab biosimilar, and BSC, respectively. The incremental costs for ranibizumab biosimilar over a patient lifetime excluding the cap on copayment were estimated to be JPY - 138,948, JPY - 391,935, JPY - 209,099, and JPY - 6,377,345, compared with branded ranibizumab, aflibercept, aflibercept switching to ranibizumab biosimilar, and BSC, respectively.

CONCLUSIONS

Ranibizumab biosimilar was demonstrated as a cost-saving option compared to aflibercept across all subtypes of nAMD, irrespective of the perspectives considered.

Bevacizumab First in DRCR Protocol AC vs Real-World Physician Treatment Choice for Diabetic Macular Edema: Two-Year Cost Analysis

Purpose: To compare the modeled costs of the Protocol AC bevacizumab-first treatment protocol (with a switch to aflibercept for sub-responders) with real-world costs for treatment-naïve patients with diabetic macular edema (DME) over a 2-year period. Methods: Published data from the Diabetic Retinopathy Clinical Research Network (DRCR) Protocol AC bevacizumab-first arm (154 eyes) were used to model 2-year treatment costs. Real-world costs were modeled using data from the Vestrum Health electronic medical records database from a 2016 to 2018 cohort of treatment-naïve eyes with DME (n = 1062) treated with antivascular endothelial growth factor monotherapy. The visual acuity (VA) before treatment in the real-world cohort was matched to Protocol AC. A secondary cost analysis further matched VA gains after treatment in the real-world cohort (n = 346) to Protocol AC. Results: In Protocol AC, the modeled 2-year DME treatment cost in the bevacizumab-first arm was $18,952, with a mean of 16.1 injections over 22.5 visits and 70% of eyes being switched to aflibercept by year 2. (Within 2 years, 57% of injections were bevacizumab and 43% were aflibercept.) Over the same period, the modeled 2-year real-world cost ($11,459) was 40% lower, with a mean of 8.6 injections over 13.8 visits (42% bevacizumab, 45% aflibercept, 13% ranibizumab). Even when matched for baseline VA and a 14-letter VA gain over 2 years, the real-world cost ($15,394) was still 19% lower than the modeled cost in the Protocol AC bevacizumab-first arm. Conclusions: The real-world cost of treating DME over 2 years was significantly lower than the Protocol AC bevacizumab-first cost. Application of Protocol AC findings into real-world utilization, as with step therapy mandates, should only be considered if the same intensive protocol could be followed. These data suggest that existing real-world costs that reflect physician choice are already significantly lower than protocol-mandated step therapy, even when controlling for similar VA outcomes.

Risk Factors for Meeting Criteria for Switching from Bevacizumab to Aflibercept When Treating Eyes with Diabetic Macular Edema and Visual Acuity of < 20/40

PURPOSE

To identify factors for meeting prespecified criteria for switching from bevacizumab to aflibercept in eyes with center-involved diabetic macular edema (CI-DME) and moderate vision loss initially treated with bevacizumab in DRCR Retina Network protocol AC.

DESIGN

Post hoc analysis of data from a randomized clinical trial.

PARTICIPANTS

Two hundred seventy participants with one or both eyes harboring CI-DME with visual acuity (VA) letter score of 69 to 24 (Snellen equivalent, 20/50-20/320).

METHODS

Eligible eyes were assigned to receive intravitreal aflibercept monotherapy (n = 158) or bevacizumab followed by aflibercept if prespecified criteria for switching were met between 12 weeks and 2 years (n = 154).

MAIN OUTCOME MEASURES

Meeting switching criteria: (1) at any time, (2) at 12 weeks, and (3) after 12 weeks. Associations between meeting the criteria for switching and factors measured at baseline and 12 weeks were evaluated in univariable analyses. Stepwise procedures were used to select variables for multivariable models.

RESULTS

In the group receiving bevacizumab first, older participants showed a higher risk of meeting the switching criteria at any time, with a hazard ratio (HR) for a 10-year increase in age of 1.32 (95% confidence interval [CI], 1.11-1.58). Male participants or eyes with worse baseline VA were more likely to switch at 12 weeks (for male vs. female: odds ratio [OR], 4.84 [95% CI, 1.32-17.81]; 5-letter lower baseline VA: OR, 1.30 [95% CI, 1.03-1.63]). Worse 12-week central subfield thickness (CST; 10-μm greater: HR, 1.06 [95% CI, 1.04-1.07]) was associated with increased risk of switching after 12 weeks. The mean ± standard deviation improvement in visual acuity after completing the switch to aflibercept was 3.7 ± 4.9 letters compared with the day of switching.

CONCLUSIONS

The identified factors can be used to refine expectations regarding the likelihood that an eye will meet protocol criteria to switch to aflibercept when treatment is initiated with bevacizumab. Older patients are more likely to be switched. At 12 weeks, thicker CST was predictive of eyes most likely to be switched in the future.

FINANCIAL DISCLOSURE(S)

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

Counting the Cost of Cellular and/or Tissue-Based Products in Diabetic Foot Ulcers: Is There a Justifiable Price Limit per Square Centimeter?

Objective: To identify how cellular and/or tissue-based products (CTPs) relate to value in terms of cost per quality-adjusted life years (QALYs) in wound care in comparison with treatments in other medical fields. Approach: This is a cross-sectional study and a cost-effectiveness analysis. Payment limits for each CTP were obtained via the Healthcare Common Procedure Coding System Q codes and formulated as cost inputs into a cost-utility model published for treatment of Wagner 1 diabetic foot ulcers using dehydrated human amnion and chorion allograft versus standard of care (SOC). Additional changes to cap the number of CTP applications and adjustments for recent inflation were made. The literature was searched for other cost-utility models in other diabetes-related diseases as a comparison. Results: When the payment limit was ≤$140 per square centimeter, interventions were dominant (less costly, better outcomes) compared with SOC. When the limit exceeded $430 per square centimeter, the cost-effectiveness threshold of $100,000/QALY was exceeded. Newer Q codes are generally much more expensive and likely to not be cost-effective, similar to the results for many other chronic diabetes-related diseases . Innovation: This study presents decision makers with tools, by which they can determine as to whether a given CTP is likely to be cost-effective for patients. Conclusion: Over a third of all CTPs will very likely result in noncost-effective interventions. This number is likely to be higher when wounds are larger or used in other wound types where they are less efficacious. The recent trend in much higher costs for CTPs is worrisome.

Suppression of Neovascularization by Topical and Subconjunctival Bevacizumab After High-Risk Corneal Transplantation

Purpose

To assess the effectiveness of topical and subconjunctival bevacizumab in suppressing vascularization in graft and host bed after high-risk corneal transplantation.

Design

Secondary analysis of prospective, randomized, double-blind, placebo-controlled multicentric clinical trial.

Participants

The study includes patients aged > 18 years who underwent high-risk penetrating keratoplasty, which was defined as corneal vascularization in ≥ 1 quadrants of the corneal graft and host bed, excluding the limbus.

Methods

Patients were randomized to treatment and control groups. The patients in the treatment group received subconjunctival injection of bevacizumab (2.5 mg/0.1 ml) on the day of the procedure, followed by topical bevacizumab (10 mg/ml) 4 times per day for 4 weeks. The patients in control group received injection of vehicle (0.9% sodium chloride) on the day of procedure, followed by topical vehicle (carboxymethylcellulose sodium 1%) 4 times a day for 4 weeks.

Main Outcome Measures

Vessel and invasion area of vessels in the corneal graft and host beds.

Results

This study included 56 eyes of 56 patients who underwent high-risk corneal transplantation, with equal numbers in the bevacizumab and vehicle (control) treatment groups. The mean age of patients who received bevacizumab was 61.2 ± 15.9 years, and the mean age of those treated with vehicle was 60.0 ± 16.1 years. The vessel area at baseline was comparable in the bevacizumab (16.72% ± 3.19%) and control groups (15.48% ± 3.12%; P = 0.72). Similarly, the invasion areas were also similar in the treatment (35.60% ± 2.47%) and control (34.23% ± 2.64%; P = 0.9) groups at baseline. The reduction in vessel area was significantly higher in the bevacizumab-treated group (83.7%) over a period of 52 weeks compared with the control group (61.5%; P < 0.0001). In the bevacizumab-treated group, invasion area was reduced by 75.8% as compared with 46.5% in the control group. The vessel area was similar at 52 weeks postprocedure in cases of first (3.54% ± 1.21%) and repeat (3.80% ± 0.40%) corneal transplantation in patients who received bevacizumab treatment. In the vehicle-treated patients, the vessel area was significantly higher in repeat (9.76% ± 0.32%) compared with first (8.06% ± 1.02%; P < 0.0001) penetrating keratoplasty. In the bevacizumab treatment group, invasion areas at week 52 were comparable in first (11.70% ± 3.38%) and repeat (11.64% ± 1.74%) procedures, whereas invasion area was significantly higher in repeat (27.87% ± 2.57%) as compared with first (24.11% ± 2.17%) penetrating keratoplasty in vehicle-treated patients.

Conclusions

In patients undergoing vascularized high-risk corneal transplantation, bevacizumab is efficacious in reducing vascularization of corneal graft and host bed, thereby reducing the risk of corneal graft rejection in vascularized host beds.

Financial Disclosures

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

Aflibercept versus ranibizumab for diabetic macular edema: A meta-analysis

OBJECTIVE

The purpose of this study was to compare the efficacy and safety of aflibercept (AFL) versus ranibizumab (RAN) for the treatment of diabetic macular edema (DME).

METHODS

The PubMed, Embase, Cochrane Library, and CNKI databases were searched up to September 2022 to identify prospective randomized controlled trials (RCTs) comparing AFL with RAN for the treatment of DME. Review Manager 5.3 software was used for data analysis. We used the GRADE system to evaluate the quality of the evidence for each outcome.

RESULTS

A total of 8 RCTs involving 1067 eyes (939 patients) were included; there were 526 eyes in the AFL group and 541 eyes in the RAN group. Meta-analysis revealed that there was no significant difference between RAN and AFL in the best-corrected visual acuity (BCVA) of DME patients at 6 months (WMD: -0.05, 95% CI  =  -0.12 to 0.01, moderate quality) and 12 months after injection (WMD: -0.02, 95% CI  =  -0.07 to 0.03, moderate quality). Additionally, there was no significant difference between RAN and AFL in the reduction of central macular thickness (CMT) at 6 months (WMD: -0.36, 95% CI  =  -24.99 to 24.26, very low quality) and 12 months after injection (WMD: -6.36, 95% CI  =  -16.30 to 3.59, low quality). Meta-analysis showed that the number of intravitreal injections (IVIs) for AFL was significantly lower than that for RAN (WMD: -0.47, 95% CI  =  -0.88 to -0.05, very low quality). There were fewer adverse reactions to AFL than to RAN, but the difference was not significant.

CONCLUSION

This study found that there was no difference in BCVA, CMT or adverse reactions between AFL and RAN at 6 and 12 months of follow-up, but AFL needed fewer IVIs than RAN.

Efficient Expression of Functionally Active Aflibercept with Designed N-glycans

Aflibercept is a therapeutic recombinant fusion protein comprising extracellular domains of human vascular endothelial growth factor receptors (VEGFRs) and IgG1-Fc. It is a highly glycosylated protein with five N-glycosylation sites that might impact it structurally and/or functionally. Aflibercept is produced in mammalian cells and exhibits large glycan heterogeneity, which hampers glycan-associated investigations. Here, we report the expression of aflibercept in a plant-based system with targeted N-glycosylation profiles. Nicotiana benthamiana-based glycoengineering resulted in the production of aflibercept variants carrying designed carbohydrates, namely, N-glycans with terminal GlcNAc and sialic acid residues, herein referred to as AFLIGnGn and AFLISia, respectively. Both variants were transiently expressed in unusually high amounts (2 g/kg fresh leaf material) in leaves and properly assembled to dimers. Mass spectrometric site-specific glycosylation analyses of purified aflibercept showed the presence of two to four glycoforms in a consistent manner. We also demonstrate incomplete occupancy of some glycosites. Both AFLIGnGn and AFLISia displayed similar binding potency to VEGF165, with a tendency of lower binding to variants with increased sialylation. Collectively, we show the expression of functionally active aflibercept in significant amounts with controlled glycosylation. The results provide the basis for further studies in order to generate optimized products in the best-case scenario.