The evolving treatment options for diabetic macular edema

Safety and Efficacy of Brolucizumab in the Treatment of Diabetic Macular Edema and Diabetic Retinopathy: A Systematic Review and Meta-Analysis

PURPOSE

To investigate the efficacy and safety of brolucizumab in diabetic macular edema (DME) and diabetic retinopathy (DR).

METHODS

In this systematic review and meta-analysis, an electronic search was done to acquire all articles describing brolucizumab use in patients with DME and DR. The review was prospectively registered on PROSPERO (CRD42022382625). Collected articles were filtered through two stages by independent reviewers. Data were extracted from the included articles and then analyzed accordingly.

RESULTS

Brolucizumab induced significant improvement in best-corrected visual acuity and was either better or non-inferior to other types of anti-VEGF (MD -0.64 mu, 95% CI [-1.15, -0.13], P = .01); the same observation was noted with regards to central subfield macular thickness (CSMT) (MD -138.6 mu, 95% CI [-151.9, -125.3], P = .00001). Brolucizumab was reported to be relatively safe for use in diabetic patients, with few adverse events observed, with a higher frequency of adverse events in relation to the 3 mg dose compared to the 6 mg dose.

CONCLUSION

Brolucizumab is a new drug that has potential advantages in efficacy over other anti-VEGF agents in the treatment of DME and DR. It showed significant improvement in BCVA and CSMT with the possibility of a lower dosing schedule compared to other agents. Although observed in low frequency, sight-threatening adverse effects appear to occur more frequently compared to other anti-VEGF agents. The main observed adverse event was retinal vasculitis which was seen more commonly with the 3 mg dose versus the 6 mg dose.

Diversity when interpreting evidence in network meta-analyses (NMAs) on similar topics: an example case of NMAs on diabetic macular oedema

BACKGROUND

Different network meta-analyses (NMAs) on the same topic result in differences in findings. In this review, we investigated NMAs comparing aflibercept with ranibizumab for diabetic macular oedema (DME) in the hope of illuminating why the differences in findings occurred.

METHODS

Studies were searched for in English and Chinese electronic databases (PubMed, Embase, Cochrane Library, Web of Science, CNKI, Wanfang, VIP; see detailed search strategy in the main body). Two independent reviewers systematically screened to identify target NMAs that included a comparison of aflibercept and ranibizumab in patients with DME. The key outcome of interest in this review is the change in best-corrected visual acuity (BCVA), including various ways of reporting (such as the proportion of participants who gain ≥ 10 ETDRS letters at 12 months; average change in BCVA at 12 months).

RESULTS

For the binary outcome of BCVA, different NMAs all agreed that there is no clear difference between the two treatments, while continuous outcomes all favour aflibercept over ranibizumab. We discussed four points of particular concern that are illustrated by five similar NMAs, including network differences, PICO (participants, interventions, comparators, outcomes) differences, different data from the same measures of effect, and differences in what is truly significant.

CONCLUSIONS

A closer inspection of each of these trials shows how the methods, including the searches and analyses, all differ, but the findings, although presented differently and sometimes interpreted differently, were similar.

Different Anti-Vascular Endothelial Growth Factor for Patients With Diabetic Macular Edema: A Network Meta-Analysis

Background: Antiangiogenic therapy with anti-vascular endothelial growth factor (VEGF) is commonly used to treat diabetic macular edema (DME), which can reduce edema, improve vision, and prevent further visual loss. There is little head-to-head trial data to guide the selection of an individual VEGF inhibitor. Therefore, we aimed to investigate the efficacy and safety of anti-VEGF for patients with DME and to assess the differences between clinically relevant options by using network meta-analysis (NMA).

Methods: MEDLINE, Embase, the Cochrane Library, Web of Science, Chinese Biomedical Literature Database, Wanfang, China National Knowledge Infrastructure, and VIP databases were searched for published randomized controlled trials (RCTs) from their inception to November 2020. We included RCTs of anti-VEGF drugs (intravitreal aflibercept (IVT-AFL), intravitreal ranibizumab (IVR), and intravitreal conbercept (IVC)) treating adult patients who were diagnosed with DME, regardless of stage or duration of the disease. We estimated summary odds ratios (ORs) and mean differences (MDs) with 95% credible intervals (CrIs) using a Bayesian NMA. This study’s registration number is CRD42021259335.

Results: We identified 43 RCTs comprising 8,234 patients. Beneficial effects were observed in patients who used IVT-AFL compared with those who used other anti-VEGF therapies at 1-year follow-up on corrected visual acuity (BCVA) improvements (all patients: versus IVR: MD 2.83, 95% CrIs 1.64, 4.01, versus IVC: MD 2.41, 95% CrIs −0.52, 5.32; patients with worse baseline visual acuity (VA): versus IVR: MD 3.39, 95% CrIs 1.89, 4.9, versus IVC: MD 3.49, 95% CrIs 0.49, 6.44) and the proportion of patients with a gain of at least 15 Early Treatment Diabetic Retinopathy Study (ETDRS) letters (all patients: versus IVR: OR 1.55, 95% CrIs 1.11, 2.17, versus IVC: OR 2.78, 95% CrIs 1.23, 6.04; patients with worse baseline VA: versus IVR: OR 2.05, 95% CrIs 1.18, 3.58, versus IVC: OR 2.85, 95% CrIs 1.24, 6.41). The effect of improvement in BCVA was identified for IVT-AFL compared to intravitreal bevacizumab. Based on the surface under the cumulative ranking curve (SUCRA), IVT-AFL had the highest probability of being the most effective option (99.9% and 99.5% in terms of the two primary outcomes, respectively). At the 2-year follow-up, numerical differences were identified favoring IVT-AFL; however, they did not reach statistical significance when comparing IVT-AFL to IVR. In the analysis of adverse events, IVT-AFL showed a lower risk of incidence of ocular adverse events compared to other anti-VEGF therapies at 1-year follow-up (versus IVR: OR 0.45, 95% CrIs 0.28, 0.7; versus IVC: OR 0.36, 95% CrIs 0.21, 0.63).

Conclusion: IVT-AFL resulted in greater beneficial effects on BCVA and a higher proportion of patients with a gain of at least 15 ETDRS letters compared to IVR or IVC one year after treatment (especially in DME patients with worse baseline VA). In addition, fewer ocular adverse events occurred in the IVT-AFL group compared to the IVR or IVC groups. After two years, there was insufficient evidence to identify which anti-VEGF has superior efficacy or safety.

Clinical Trial Registration:https://www.crd.york.ac.uk/prospero/, PROSPERO; https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021259335, CRD42021259335

Intravitreal bevacizumab versus intravitreal triamcinolone for diabetic macular edema-Systematic review, meta-analysis and meta-regression

BACKGROUND

The most frequent cause of vision loss from diabetic retinopathy is diabetic macular edema (DME). Earlier clinical trials tried to examine the role of intravitreal triamcinolone (IVT) and intravitreal bevacizumab (IVB) in DME; they either qualified IVT over IVB or IVB over IVT or did not exhibit a significant difference.

OBJECTIVE

This paper aims to compare the efficacy and safety of IVB versus IVT alone or combined IVB+IVT in the treatment of DME.

METHODS

We systematically searched PubMed, CENTRAL, Scopus, Embase, Science Direct, OVID, and Web of Science for randomized controlled trials of IVB versus IVT alone or combined IVB+IVT and IVT versus the combined IVB+IVT in DME patients.

RESULTS

A total of 1243 eyes of 17 trials were included in our meta-analysis and regression. Repeated injections of IVB were superior at improving VA comparing with those of IVT at 12, 24, 48-weeks, and IVB+IVT at 12, 24, 48-weeks. Single injections were comparable across the three arms regarding BCVA improvement. CMT reductions were also comparable across the three arms. Meanwhile, the overall safety regarding intraocular pressure and intraocular hypertension significantly favored the IVB group. Improvement in VA was best modified with CMT reduction from 480 um to 320um. This association was significant at 12-weeks in the three arms and persisted till 24-weeks and 48-weeks exclusively in the IVB group.

CONCLUSIONS AND RELEVANCE

Our analysis reveals that repeated successive injections associate with better BCVA compared to single injection. Current evidence affirms that IVB is superior to IVT and IVB+IVT at improving BCVA, comparable at reducing CMT, and presents a better safety profile in the treatment of DME.

Clear, Aqueous Topical Drop of Triamcinolone Acetonide

The objective of this study was to develop a clear aqueous mixed nanomicellar formulation (NMF) of triamcinolone acetonide (TA) with a combination of nonionic surfactant hydrogenated castor oil 60 (HCO-60) and octoxynol-40 (Oc-40). In order to delineate the effects of drug-polymer interactions on entrapment efficiency (EE), loading efficiency (LE), and critical micellar concentration (CMC), a design of experiment (DOE) was performed to optimize the formulation. In this study, full-factorial design has been used with HCO-60 and OC-40 as independent variables. All formulations were prepared following solvent evaporation and film rehydration method, characterized with size, polydispersity, shape, morphology, EE, LE, and CMC. A specific blend of HCO-60 and Oc-40 at a particular wt% ratio (5:1.5) produced highest drug EE, LE, and smallest CMC (0.0216 wt%). Solubility of TA in NMF improved 20 times relative to normal aqueous solubility. Qualitative ¹H NMR studies confirmed the absence of free drug in the outer aqueous NMF medium. Moreover, TA-loaded NMF appeared to be highly stable and well tolerated on human corneal epithelial cells (HCEC) and human retinal pigment epithelial cells (D407 cells). Overall, these studies suggest that TA in NMF is safe and suitable for human topical ocular drop application.

Fundamental principles of an anti-VEGF treatment regimen: optimal application of intravitreal anti-vascular endothelial growth factor therapy of macular diseases

BACKGROUND

Intravitreal anti-vascular endothelial growth factor (VEGF) therapy is now considered the gold standard for the treatment of various retinal disorders. As therapy has evolved, so too have the treatment regimens employed by physicians in clinical practice; however, visual outcomes observed in the real world have typically not reflected those reported in clinical trials. Possible reasons for this include a lack of consensus on treatment regimens and a lack of clarity about what the aims of treatment should be.

METHODS

The Vision Academy Steering Committee met to discuss the principles of an ideal treatment regimen, using evidence from the literature to substantiate each point. Literature searches were performed using the MEDLINE/PubMed database (cut-off date: March 2016) and restricted to English-language publications. Studies with fewer than ten patients were excluded from this review.

RESULTS

The Steering Committee identified the following four key principles for the ideal treatment regimen for anti-VEGF management of retinal diseases: 1. Maximize and maintain visual acuity (VA) benefits for all patients 2. Decide when to treat next, rather than whether to treat now 3. Titrate the treatment intervals to match patients' needs 4. Treat at each monitoring visit.

CONCLUSIONS

It is proposed that the adoption of a proactive and more personalized approach in the clinic such as a treat-and-extend regimen will lead to benefits for both the patient and the physician, through a reduction in the associated treatment burden and better utilization of clinic resources. Implementation of the four principles should also lead to better VA outcomes for each patient, with a minimized risk of vision loss.

Comorbidity and health care visit burden in working-age commercially insured patients with diabetic macular edema

PURPOSE

To examine the comorbidity profile and update estimates of health care resource utilization for commercially insured, working-age adults with diabetic macular edema (DME) relative to a matched comparison group of diabetic adults without DME. Additional comparisons were made in the subgroup of pseudophakic patients.

PATIENTS AND METHODS

A retrospective matched-cohort study of commercially insured diabetic adults aged 18-63 years was conducted using medical and outpatient pharmacy claims (July 1, 2008-June 30, 2013). Outcomes included diabetes-related and ocular comorbidities and health care resource utilization (any health care visit days, outpatient visit days, inpatient visit days, emergency room visits, eye care-related visit days, unique medications) in the 12-month post-index period.

RESULTS

All diabetes-related and ocular comorbidities were significantly more prevalent in DME cases versus non-DME controls (P<0.05). A significantly greater proportion of DME cases utilized eye care-related visits compared with non-DME controls (P<0.001). DME cases had almost twice the mean number of total health care visit days compared to non-DME controls (28.6 vs 16.9 days, P<0.001), with a minority of visit days being eye care-related (mean 5.1 vs 1.5 days, P<0.001). Similar trends were observed in pseudophakic cohorts.

CONCLUSION

This working-age DME population experienced a mean of 29 health care visit days per year. Eye care-related visit days were a minority of the overall visit burden (mean 5 days) emphasizing the trade-offs DME patients face between managing DME and their overall diabetic disease. Insights into the complex comorbidity profile and health care needs of diabetic patients with DME will better inform treatment decisions and help optimize disease management.

A multicenter, 12-month randomized study comparing dexamethasone intravitreal implant with ranibizumab in patients with diabetic macular edema

PURPOSE

To evaluate whether treatment with dexamethasone intravitreal implant (DEX implant) 0.7 mg every 5 months provides a similar average change in best-corrected visual acuity (BCVA) from baseline as ranibizumab 0.5 mg administered as per its European Summary of Product Characteristics in patients with diabetic macular edema (DME).

METHODS

This was a multicenter, open-label, 12-month, randomized, parallel-group, noninferiority study in patients with DME (one eye/patient). The primary efficacy measure was BCVA using the Early Treatment Diabetic Retinopathy Study (ETDRS) method. Secondary efficacy measures included area of leakage on fluorescein angiography and central retinal thickness (CRT) on optical coherence tomography.

RESULTS

Baseline patient characteristics were similar in the two treatment groups (DEX implant, n = 181; ranibizumab, n = 182); mean DME duration was ∼33 months. The mean average BCVA change from baseline over 12 months was 4.34 letters with DEX implant and 7.60 letters with ranibizumab. The lower limit of the 95 % confidence interval of the between-group difference was -4.74 letters, and therefore, DEX was demonstrated to be noninferior to ranibizumab based on the prespecified noninferiority margin of 5 letters. At monthly follow-up visits, the percentage of patients with ≥15-letter BCVA gain from baseline ranged from 7.2 to 17.7 % with DEX implant and 4.4 to 26.9 % with ranibizumab. Both DEX implant and ranibizumab effectively reduced CRT and reduced the area of fluorescein leakage. Between-group differences in change from baseline CRT favored DEX implant at 1, 2, 6, and 7 months (p ≤ 0.007) and ranibizumab at 4, 5, 9, and 10 months (p < 0.001); the decrease in fluorescein leakage area was greater with DEX implant than ranibizumab at month 12 (p < 0.001). Ocular adverse events in the study eye were more frequent in the DEX implant group because of the occurrence of intraocular pressure (IOP) increases and cataract. IOP increases were transient and generally managed with topical medication.

CONCLUSIONS

Both DEX implant and ranibizumab were well tolerated and improved BCVA and anatomic outcomes in patients with DME. DEX implant met the a priori criterion for noninferiority to ranibizumab in average change from baseline BCVA over 12 months. Noninferiority was achieved with an average of 2.85 DEX implant injections and 8.70 ranibizumab injections per patient.

Novel strategies for the treatment of diabetic macular edema

Macular edema such as diabetic macular edema (DME) and diabetic retinopathy are devastating back-of-the-eye retinal diseases leading to loss of vision. This area is receiving considerable medical attention. Posterior ocular diseases are challenging to treat due to complex ocular physiology and barrier properties. Major ocular barriers are static (corneal epithelium, corneal stroma, and blood-aqueous barrier) and dynamic barriers (blood-retinal barrier, conjunctival blood flow, lymph flow, and tear drainage). Moreover, metabolic barriers impede posterior ocular drug delivery and treatment. To overcome such barriers and treat back-of-the-eye diseases, several strategies have been recently developed which include vitreal drainage, laser photocoagulation and treatment with biologics and/or small molecule drugs. In this article, we have provided an overview of several emerging novel strategies including nanotechnology based drug delivery approach for posterior ocular drug delivery and treatment with an emphasis on DME.

Modern diagnostic and treatment aspects of diabetic macular edema

Diabetic macular oedema (DMO) is the leading cause of vision loss and disability in working-age people with diabetes mellitus. This literature review describes pathogenetic mechanisms, concepts, diagnostic techniques and capabilities of novel laser technologies in the treatment of DMO. In recent years, the role of cytokines and growth factors in retinal neurodegeneration has been actively investigated. Modern diagnostic techniques for the treatment of diabetic macular oedema, in addition to conventional techniques, include optical coherence tomography, autofluorescence and microperimetry. These techniques allow the visualization of retinal structures and its functional condition, and they can be used to detect DMO at early stages and to provide the most effective treatment. The evolution of laser technology resulted in the formation of new approaches to DMO treatment. Subthreshold micropulse laser (SML) treatment, in conjunction with conventional photocoagulation, has pronounced therapeutic effects. SML shows high selectivity towards retinal pigment epithelium while avoiding neurosensory retina injury. Owing to the chronic nature of DMO and pathogenetic mechanisms recently discovered, further elaboration of the SML technique appears to be a very promising treatment.

Efficacy of anti-VEGF and laser photocoagulation in the treatment of visual impairment due to diabetic macular edema: a systematic review and network meta-analysis

OBJECTIVE

Compare the efficacy of ranibizumab, aflibercept, laser, and sham in the first-line treatment of diabetic macular edema (DME) to inform technology assessments such as those conducted by the UK National Institute for Health and Care Excellence (NICE).

DATA SOURCES

MEDLINE, Embase, Cochrane Library, congress abstracts, ClinicalTrials.gov registry and Novartis data on file.

INCLUSION CRITERIA

Studies reporting 6- or 12-month results of randomized controlled trials (RCTs) evaluating at least two of ranibizumab 0.5 mg pro re nata, aflibercept 2.0 mg bi-monthly, laser photocoagulation or sham. Study quality was assessed based on likelihood of bias in selection, attrition, detection and performance.

OUTCOME MEASURE

Improvement in best-corrected visual acuity (BCVA) measured as the proportion of patients gaining ≥10 letters on the Early Treatment Diabetic Retinopathy Study scale. The outcome was chosen following acceptance by NICE of a Markov model with 10-letter health states in the assessment of ranibizumab for DME.

META-ANALYSIS

Bayesian network meta-analyses with fixed and random effects adjusted for differences in baseline BCVA or central retinal thickness.

RESULTS

The analysis included 1,978 patients from eight RCTs. The random effects model adjusting for baseline BCVA was the best model based on total residual. The efficacy of ranibizumab was numerically, but not statistically, superior to aflibercept (odds ratio [OR] 1.59; 95% credible interval [CrI], 0.61-5.37). Ranibizumab and aflibercept were statistically superior to laser monotherapy with ORs of 5.50 (2.73-13.16) and 3.45 (1.62-6.84) respectively. The probability that ranibizumab is the most efficacious treatment was 73% compared with 14% for aflibercept, 12% for ranibizumab plus laser, and 0% for laser.

LIMITATIONS

Three of the eight RCTs included are not yet published. The models did not adjust for all potential effect modifiers.

CONCLUSION

Ranibizumab was non-significantly superior to aflibercept and both anti-VEGF therapies had statistically superior efficacy to laser.