Intravitreal aflibercept for diabetic macular edema

Individualized Treatment of Neovascular Age-Related Macular Degeneration: What are Patients Gaining? Or Losing?

The widespread use of drugs that bind diffusible vascular endothelial growth factor (VEGF) has revolutionized the treatment of neovascular age-related macular degeneration (AMD). The pivotal ranibizumab and aflibercept registration trials featured monthly intravitreal injections for 12 months, during which visual acuities and macular edema rapidly improved for the first 3 months and modest gains or stabilization continued until the primary endpoint. In many subsequent trials, patients were evaluated monthly and treated as-needed (PRN) according to the results of visual acuity (VA) testing, fundus examinations and optical coherence tomography scans. Compared to monthly-treated control groups, PRN treated patients require fewer injections during the first year but they also experience smaller VA gains (1-3 letters). A small number of prospective trials that directly compared monthly with PRN therapy showed that VA gains with discontinuous therapy lag slightly behind those achieved with monthly injections. Physicians recognize that monthly office visits with frequent intraocular injections challenge patients' compliance, accrue high drug and professional service costs, and clog office schedules with frequently returning patients. To decrease the numbers of both office visits and anti-VEGF injections without sacrificing VA gains, physicians have embraced the treat-and-extend strategy. Treat-and-extend has not been studied as rigorously as PRN but it has become popular among both vitreoretinal specialists and patients. Despite the possible risks associated with discontinuous therapy (decreased VA and increased macular fluid), most physicians individualize treatment (PRN or treat-and-extend) for the majority of their patients. This review chapter explores the many advantages of individualized therapy, while balancing these against suboptimal responses due to the decreased frequency of anti-VEGF injections.

Aflibercept versus ranibizumab for treating persistent diabetic macular oedema

The purpose of this study was to compare the efficacy of intravitreal aflibercept versus ranibizumab for treating therapy-resistant diabetic macular oedema (DME). A 69-year-old man presented with persistent bilateral DME despite previous ranibizumab treatment. Bilateral study treatment comprised one cycle of three monthly ranibizumab injections (0.5 mg), followed by one cycle of three aflibercept injections (2.0 mg), a second ranibizumab cycle and a second aflibercept cycle. Baseline visual acuity (ETDRS score) was 60 letters for the right eye and 65 letters for the left eye. Baseline central foveal thickness (CFT) was 305 μm for the right eye and 453 μm for the left eye. Substantially improved outcomes were observed during the first aflibercept cycle. CFT was reduced by 150 μm (mean) in both the eyes and decreased below the lowest level achieved during the previous 2.5-year ranibizumab treatment. Visual acuity was improved by 17.5 letters (mean) in both the eyes. Reintroduction of ranibizumab immediately worsened the status of both eyes back to the baseline level. During the final aflibercept cycle, visual acuity and CFT improved to the same levels achieved during the first aflibercept cycle. In this case study, we prospectively switched the treatment three times and observed a dramatic and consistent treatment advantage for aflibercept.

Systematic review and mixed treatment comparison of intravitreal aflibercept with other therapies for diabetic macular edema (DME)

Background

This was an indirect comparison of the effectiveness of intravitreal aflibercept (IVT-AFL) 2 mg every 8 weeks after 5 initial monthly doses (or if different periods, after an initial monthly dosing period) (2q8) and other diabetic macular edema (DME) therapies at doses licensed outside the USA.

Methods

A comprehensive search was undertaken to source relevant studies. Feasibility networks were prepared to identify viable comparisons of 12-month outcomes between IVT-AFL 2q8 and therapies licensed outside the USA, which were assessed for clinical and statistical homogeneity. Pooled effect sizes (mean difference [MD] and relative risk/risk ratio [RR]) were calculated using fixed- and random-effects models. Indirect comparisons were performed using Bucher analysis. If at least one ‘head-to-head’ study was found then a mixed treatment comparison (MTC) was performed using Bayesian methods. Two 12-month comparisons could be undertaken based on indirect analyses: IVT-AFL 2q8 versus intravitreal ranibizumab (IVR) 0.5 mg as needed (PRN) (10 studies) and IVT-AFL 2q8 versus dexamethasone 0.7 mg implants (three studies).

Results

There was an increase in mean best-corrected visual acuity (BCVA) with IVT-AFL 2q8 over IVR 0.5 mg PRN by 4.67 letters [95% credible interval (CrI): 2.45–6.87] in the fixed-effect MTC model (10 studies) and by 4.82 letters [95% confidence interval (CI): 2.52–7.11] in the Bucher indirect analysis (four studies). IVT-AFL 2q8 doubled the proportion of patients gaining ≥ 10 Early Treatment Diabetic Retinopathy Study letters at 12 months compared with dexamethasone 0.7 mg implants (RR = 2.10 [95% CI: 1.29–3.40]) in the fixed-effect model. There were no significant differences in safety outcomes between IVT-AFL 2q8 and IVR 0.5 mg PRN or dexamethasone 0.7 mg implants.

Conclusions

Studies of IVT-AFL 2q8 showed improved 12-month visual acuity measures compared with studies of IVR 0.5 mg PRN and dexamethasone 0.7 mg implants based on indirect comparisons. These analyses are subject to a number of limitations which are inherent in indirect data comparisons.

Electronic supplementary material

The online version of this article (doi:10.1186/s12886-015-0035-x) contains supplementary material, which is available to authorized users.

New treatments for diabetic macular edema

This work comprehensively reviews the latest treatment options for diabetic macular edema (DME) used in its management and presents further work on the topic. Diabetic retinopathy is an important and increasingly prevalent cause of preventable blindness worldwide. To meet this increasing burden there has recently been a proliferation of pharmacological therapies being used in clinical practice. A variety of medical treatment options now exist for DME. These include non-steroidal anti-inflammatory drugs such as nepafenac, as well as intravitreal steroids like triamcinolone (kenalog). Long-term results up to 7 years after commencing treatment are presented for triamcinolone. Studies are reviewed on the use of dexamethasone (ozurdex) and fluocinolone (Retisert and Iluvien implants) including the FAME studies. A variety of anti-vascular endothelial growth factor (anti-VEGF) agents used in DME are considered in detail including ranibizumab (lucentis) and the RESTORE, RIDE, RISE and Diabetic Retinopathy Clinical Research Network (DRCR.net) studies. Bevacizumab (avastin) and pegaptinib (macugen) are also considered. The use of aflibercept (eylea) is reviewed including the significance of the DA VINCI, VISTA-DME, VIVID-DME and the DRCR.net studies which have recently suggested potentially greater efficacy when treating DME for aflibercept in patients with more severely reduced visual acuity at baseline. Evidence for the anti-VEGF agent bevasiranib is also considered. Studies of anti-tumour necrosis factor agents like infliximab are reviewed. So are studies of other agents targeting inflammation including minocycline, rapamycin (sirolimus) and protein kinase C inhibitors such as midostaurin and ruboxistaurin. The protein kinase C β inhibitor Diabetic Macular Edema Study is considered. Other agents which have been suggested for DME are discussed including cyclo-oxygenase-2 inhibitors like celecoxib, phospholipase A2 inhibitors, recombinant erythropoietin, and monoclonal anti-interleukin antibodies such as canakinumab. The management of DME in a variety of clinical scenarios is also discussed - in newly diagnosed DME, refractory DME including after macular laser, and postoperatively after intraocular surgery. Results of long-term intravitreal triamcinolone for DME administered up to seven years after commencing treatment are considered in the context of the niche roles available for such agents in modern management of DME. This is alongside more widely used treatments available to the practitioner such as anti-VEGF agents like aflibercept (Eylea) and ranibizumab (Lucentis) which at present are the mainstay of pharmacological treatment of DME.

Recent Innovations in Medical and Surgical Retina

PURPOSE

To summarize major innovations in retinal disease management during fiscal year 2014.

DESIGN

Literature review.

METHODS

A subset of papers published in the peer-reviewed literature were selected.

RESULTS

Major innovations in retina include: (1) advances in the treatment of diabetic macular edema, including the use of aflibercept and sustained delivery dexamethasone intravitreal implants as well as subthreshold micropulse diode laser therapy; (2) reduced progression of age-related macular degeneration (AMD) using zinc, vitamin C, vitamin E, lutein, and zeaxanthin supplements as reported in the Age-Related Eye Disease Study-2; (3) use of enhanced-depth imaging optical coherence tomography for choroidal imaging; (4) use of gene therapy to treat choroideremia; (5) use of combination pharmacotherapy (i.e., squalamine + ranibizumab) and gene therapy to treat the neovascular complications of AMD; and (6) use of stem cell-derived retinal pigment epithelium transplants to treat atrophic AMD and Stargardt macular dystrophy. In addition, we review the ocular and systemic risks associated with sustained intraocular steroid delivery and inhibition of vascular endothelial growth factor signaling pathways. We also review potential applications of gene- versus cell-based therapy for the treatment of retinal degenerative diseases.

CONCLUSIONS

Several treatment approaches are effective in the treatment of diabetic macular edema. Prophylaxis against AMD progression with Age-Related Eye Disease Study-2 supplements seems to reduce the risk of developing neovascular but not atrophic complications of AMD. Enhanced-depth imaging optical coherence tomography data provide new information on the role of the choroid in a variety of conditions. Advances in gene- and cell-based therapy will revolutionize the development of regenerative medicine in ophthalmology.

Novel pharmacotherapies in diabetic retinopathy

This is a summary of current and emerging pharmacologic therapies utilized in the treatment of diabetic retinopathy (DR). Current therapies, such as ranibizumab, bevacizumab, triamcinolone acetonide, and fluocinolone acetonide, inhibit angiogenesis and inflammation and may be used alone or in combination with laser treatment. Emerging therapies aim to reduce oxidative stress or inhibit other signal transduction pathways, including the protein kinase C cascade and aldose reductase pathway. Future therapies may target other molecules crucial to the pathogenesis of DR, including hepatocyte growth factors and matrix metalloproteinase 9. Finally, the emergence of novel mechanisms of medication delivery may also be on the horizon.

Aflibercept, bevacizumab, or ranibizumab for diabetic macular edema

BACKGROUND

The relative efficacy and safety of intravitreous aflibercept, bevacizumab, and ranibizumab in the treatment of diabetic macular edema are unknown.

METHODS

At 89 clinical sites, we randomly assigned 660 adults (mean age, 61±10 years) with diabetic macular edema involving the macular center to receive intravitreous aflibercept at a dose of 2.0 mg (224 participants), bevacizumab at a dose of 1.25 mg (218 participants), or ranibizumab at a dose of 0.3 mg (218 participants). The study drugs were administered as often as every 4 weeks, according to a protocol-specified algorithm. The primary outcome was the mean change in visual acuity at 1 year.

RESULTS

From baseline to 1 year, the mean visual-acuity letter score (range, 0 to 100, with higher scores indicating better visual acuity; a score of 85 is approximately 20/20) improved by 13.3 with aflibercept, by 9.7 with bevacizumab, and by 11.2 with ranibizumab. Although the improvement was greater with aflibercept than with the other two drugs (P<0.001 for aflibercept vs. bevacizumab and P=0.03 for aflibercept vs. ranibizumab), it was not clinically meaningful, because the difference was driven by the eyes with worse visual acuity at baseline (P<0.001 for interaction). When the initial visual-acuity letter score was 78 to 69 (equivalent to approximately 20/32 to 20/40) (51% of participants), the mean improvement was 8.0 with aflibercept, 7.5 with bevacizumab, and 8.3 with ranibizumab (P>0.50 for each pairwise comparison). When the initial letter score was less than 69 (approximately 20/50 or worse), the mean improvement was 18.9 with aflibercept, 11.8 with bevacizumab, and 14.2 with ranibizumab (P<0.001 for aflibercept vs. bevacizumab, P=0.003 for aflibercept vs. ranibizumab, and P=0.21 for ranibizumab vs. bevacizumab). There were no significant differences among the study groups in the rates of serious adverse events (P=0.40), hospitalization (P=0.51), death (P=0.72), or major cardiovascular events (P=0.56).

CONCLUSIONS

Intravitreous aflibercept, bevacizumab, or ranibizumab improved vision in eyes with center-involved diabetic macular edema, but the relative effect depended on baseline visual acuity. When the initial visual-acuity loss was mild, there were no apparent differences, on average, among study groups. At worse levels of initial visual acuity, aflibercept was more effective at improving vision. (Funded by the National Institutes of Health; ClinicalTrials.gov number, NCT01627249.).

Intravitreal Aflibercept Injection in Patients with Myopic Choroidal Neovascularization: The MYRROR Study

PURPOSE

To evaluate intravitreal aflibercept 2 mg in patients with myopic choroidal neovascularization (CNV).

DESIGN

An international, phase III, multicenter, randomized, double-masked, sham-controlled study.

PARTICIPANTS

Patients aged ≥ 18 years with high myopia (≤-6.0 diopters or axial length of ≥ 26.5 mm), active myopic CNV, and best-corrected visual acuity (BCVA) of 73-35 Early Treatment Diabetic Retinopathy Study letters in the study eye were included.

METHODS

Patients were randomized 3:1 to intravitreal aflibercept or sham. In the intravitreal aflibercept arm, patients received 1 injection at baseline. Additional injections were performed in case of CNV persistence or recurrence at monthly visits through week 44. In the sham arm, patients received sham injections through week 20. At week 24, after assessment of the primary efficacy end point, sham patients received a mandatory intravitreal aflibercept injection followed by intravitreal aflibercept (if disease persisted/recurred) or sham injection every 4 weeks.

MAIN OUTCOME MEASURES

Mean change in BCVA from baseline to week 24.

RESULTS

A total of 122 patients were randomized to intravitreal aflibercept (n = 91) or sham (n = 31). Baseline demographics were similar across groups. At week 24, patients in the intravitreal aflibercept and sham groups gained 12.1 and lost 2 letters, respectively (P < 0.0001). By week 48, patients in the intravitreal aflibercept and sham/intravitreal aflibercept groups gained 13.5 and 3.9 letters. Patients in the intravitreal aflibercept group received 2 injections (median) in the first study quarter (week 0-8). Median number of injections in quarters 2 to 4 was 0. Patients in the "sham/intravitreal aflibercept" group received 2 and 1 (median) intravitreal aflibercept injections in quarters 3 and 4. Central retinal thickness improved in parallel with visual gains. Incidence of ocular adverse events was similar in both groups through week 48 (37.4% vs. 38.7); most were assessed by investigators as mild. No deaths occurred.

CONCLUSIONS

Intravitreal aflibercept 2 mg was effective for treatment of myopic CNV with clinically important visual and anatomic benefits achieved with a limited number of injections given in the first 8 weeks of treatment. No new safety concerns occurred with treatment. Intravitreal aflibercept should be considered as a treatment option for myopic CNV.

Automated retinal image analysis for diabetic retinopathy in telemedicine

There will be an estimated 552 million persons with diabetes globally by the year 2030. Over half of these individuals will develop diabetic retinopathy, representing a nearly insurmountable burden for providing diabetes eye care. Telemedicine programmes have the capability to distribute quality eye care to virtually any location and address the lack of access to ophthalmic services. In most programmes, there is currently a heavy reliance on specially trained retinal image graders, a resource in short supply worldwide. These factors necessitate an image grading automation process to increase the speed of retinal image evaluation while maintaining accuracy and cost effectiveness. Several automatic retinal image analysis systems designed for use in telemedicine have recently become commercially available. Such systems have the potential to substantially improve the manner by which diabetes eye care is delivered by providing automated real-time evaluation to expedite diagnosis and referral if required. Furthermore, integration with electronic medical records may allow a more accurate prognostication for individual patients and may provide predictive modelling of medical risk factors based on broad population data.

Ziv-aflibercept in macular disease

BACKGROUND/AIMS

Aflibercept is an approved therapy for neovascular age-related macular degeneration (AMD) and diabetic macular oedema (DME). In vitro and in vivo studies did not detect toxicity to the retinal pigment epithelium cells using the approved cancer protein, ziv-aflibercept. Our purpose is to determine if ziv-aflibercept can be used in AMD and DME without ocular toxicity, to test the stability of ziv-aflibercept, and to do a cost analysis.

METHODS

Prospectively, consecutive patients with AMD or DME and poor vision underwent one intravitreal injection of 0.05 mL of fresh filtered ziv-aflibercept (1.25 mg). Monitoring of best-corrected visual acuity, intraocular inflammation, cataract progression, and retinal structure by spectral domain optical coherence tomography was done at 1 day and 1 week after injection. Ziv-aflibercept activity over 4 weeks was measured by capturing vascular endothelial growth factor by ELISA.

RESULTS

There were no signs of retinal toxicity, intraocular inflammation or change in lens status in four eyes with AMD and two eyes with DME. Visual acuity improved (p=0.05) and central foveal thickness decreased in all patients (p=0.05). Ziv-aflibercept had no loss of anti-VEGF activity when kept at 4°C in polycarbonate syringes over 4 weeks. Similar to bevacizumab, compounded ziv-aflibercept would yield a tremendous saving compared with aflibercept or ranibizumab.

CONCLUSIONS

Off-label use of ziv-aflibercept improves visual acuity without ocular toxicity and may offer a cheaper alternative to the same molecule aflibercept.

TRIAL REGISTRATION NUMBER

NCT02173873.

Cost-effectiveness of ranibizumab versus aflibercept in the treatment of visual impairment due to diabetic macular edema: a UK healthcare perspective

BACKGROUND

Ranibizumab and aflibercept are alternative anti-vascular endothelial growth factor agents approved for the treatment of visual impairment (VI) due to diabetic macular edema (DME).

OBJECTIVE

To estimate, from a UK healthcare perspective, the cost-effectiveness of ranibizumab 0.5 mg pro re nata (PRN) and ranibizumab 0.5 mg treat and extend (T&E) compared with aflibercept 2 mg every 8 weeks after five initial monthly doses (2q8) in the treatment of VI due to DME.

METHODS

A Markov model previously reviewed by the National Institute for Health and Care Excellence was used to simulate the long-term outcomes and costs of treating DME. Health states were defined by increments of ten letters in best-corrected visual acuity (BCVA), with a 3-month cycle length. Patients could gain (or lose) a maximum of two health states between cycles. A 3-year treatment time frame and a lifetime horizon were used. Future costs and health outcomes were discounted at 3.5% per annum. Patient baseline characteristics and the efficacy of ranibizumab PRN were derived using data from the RESTORE study. The relative efficacies of ranibizumab PRN, ranibizumab T&E, and aflibercept were assessed with a network meta-analysis. Different utilities were assigned based on BCVA and whether the treated eye was the better- or the worse-seeing eye. Sensitivity analyses tested the robustness of the model.

RESULTS

Lifetime costs per patient of treating DME were £20,019 for ranibizumab PRN, £22,930 for ranibizumab T&E, and £25,859 for aflibercept 2q8. Ranibizumab was dominant over aflibercept, with an incremental gain of 0.05 quality-adjusted life-years (QALYs) and cost savings of £5,841 (PRN) and £2,930 (T&E) compared with aflibercept. Ranibizumab PRN and ranibizumab T&E had 79% and 67% probability, respectively, of being cost-effective relative to aflibercept at a willingness-to-pay threshold of £20,000/QALY. When assuming the higher end of PRN injection frequency (15.9 over 3 years), the cost savings associated with ranibizumab were £3,969.

CONCLUSION

From a UK healthcare perspective, ranibizumab provides greater health gains with lower overall costs than aflibercept in patients with VI due to DME.

Role of implants in the treatment of diabetic macular edema: focus on the dexamethasone intravitreal implant

Diabetic macular edema (DME) is the leading cause of sight-threatening complication in diabetic patients, and several treatment modalities have been developed and evaluated to treat this pathology. Intravitreal agents, such as anti-vascular endothelial growth factors (anti-VEGF) or corticosteroids, have become more popular in recent years and are widely used for treating DME. Sustained release drugs appear to be mentioned more often nowadays for extending the period of intravitreal activity, and corticosteroids play a key role in inhibiting the inflammatory process in DME. A potent corticosteroid, dexamethasone (Ozurdex(®)), in the form of an intravitreal implant, has been approved for various ocular etiologies among which DME is also one. This review evaluates the role of implants in the treatment of DME, mainly focusing on the dexamethasone intravitreal implant.

Diabetic retinopathy: variations in patient therapeutic outcomes and pharmacogenomics

Diabetes and its microvascular complications in patients poses a significant challenge and constitutes a major health problem. When it comes to manifestations in the eye, each case of diabetic retinopathy (DR) is unique, in terms of the phenotype, genotype, and, more importantly, the therapeutic response. It is therefore important to identify factors that distinguish one patient from another. Personalized therapy in DR is a new trend aimed at achieving maximum therapeutic response in patients by identifying genotypic and phenotypic factors that may result in less than optimal response to conventional therapy, and consequently, lead to poorer outcome. With advances in the identification of these genetic markers, such as gene polymorphisms and human leucocyte antigen associations, as well as development of drugs that can target their effects, the future of personalized medicine in DR is promising. In this comprehensive review, data from various studies have been analyzed to present what has been achieved in the field of pharmacogenomics thus far. An insight into future research is also provided.

Current concepts in diabetic retinopathy

For the past several decades, tremendous efforts have been made to decrease the complications of diabetes, including diabetic retinopathy. New diagnostic modalities like ultrawide field fundus fluorescein angiography and spectral domain optical coherence tomography has allowed more accurate diagnosis of early diabetic retinopathy and diabetic macular edema. Antivascular endothelial growth factors are now extensively used to treat diabetic retinopathy and macular edema with promising results. There remains uncertainty over the long term effects and the socioeconomic costs of these agents.