Evaluation of clinical and genetic indicators for the early response to intravitreal ranibizumab in exudative age-related macular degeneration

Association of the Complement Factor H Y402H Polymorphism and Response to Anti-Vascular Endothelial Growth Factor Treatment in Age-Related Macular Degeneration: An Updated Meta-Analysis

INTRODUCTION

Anti-vascular endothelial growth factor (anti-VEGF) agents have a variable effect on patients with age-related macular degeneration (AMD) that has been attributed to several causes, including genetic factors. We evaluated the effects of Complement Factor H (CFH) rs1061170/Y402H polymorphism on the response to anti-VEGF therapy among AMD patients.

METHODS

PubMed, Scopus, EMBASE, Web of Science, and Google Scholar were used for a literature search. Pooled odds ratios (ORs) and their 95% confidence intervals (CIs) were estimated to assess the effects of CFH Y402H polymorphism on the response to anti-VEGF therapy in AMD. I2 was used to present the amount of heterogeneity. We used STATA version 14.0 software.

RESULTS

Twenty-five papers reporting data for 4,681 patients were included in this study. Better response to anti-VEGF therapy was seen in T over C (OR = 1.25, 95% CI = 1.04-1.50), TT over CC (OR = 1.60, 95% CI = 1.06-2.4), and TT + TC over CC (OR = 1.68, 95% CI = 1.23-2.28) genotypes. There was no significant difference in the three other genetic models (TT vs. TC, TT vs. TC + CC, TC vs. TT + CC). In Asians, no significant difference was observed in all six genetic models. Ranibizumab and bevacizumab had similar efficacy; however, conbercept was more effective in homozygous genotypes. The literature indicated that TT and TC genotypes and T allele were associated with a better functional response, while the CC genotype and C alleles had a better anatomical response. The combination of risk alleles in ARMS2 A69S (rs10490924), VEGF-A (rs699947), and VEGF-A (rs833069) with Y420H is a predictor of non-respondents.

CONCLUSION

In patients with AMD, the CFH Y402H is a predictor of the response to anti-VEGF agents and should be considered in the treatment plan.

Meta-Analysis of the Pharmacogenetics of ARMS2 A69S Polymorphism and the Response to Advanced Age-Related Macular Degeneration

Age-related macular degeneration (AMD) causes irreversible vision loss, and targeted anti-vascular endothelial growth factor (VEGF) therapy is now the most common and effective treatment. The aim of this meta-analysis is to discuss whether genetic polymorphism of ARMS2 A69S could confer susceptibility to advanced AMD with the response to anti-VEGF treatment. We performed a meta-analysis of relevant published studies selected through electronic databases. A total of 21 preferred studies regarding the association between ARMS2 gene and anti-VEGF treatment response in advanced AMD were generally included in the meta-analysis. The pooled results demonstrated that the carriage of G allele for ARMS2 A69S presented a better clinical prognosis for advanced AMD treated with anti-VEGF drugs (OR = 1.38, 95% CI = 1.13-1.69, p = 0.002). In addition, in the subgroup analysis based on ethnicity, ARMS2 polymorphisms were more likely to be a positive responder for East Asian patients (OR = 1.67, 95% CI = 1.29-2.16, p < 0.001). This meta-analysis through a series of rigorous methodology data demonstrated a significant association between ARMS2 A69S polymorphism and the anti-VEGF treatment response in advanced AMD, especially among East Asian population. Numerous well-designed, randomized, multicenter clinical trials with large sample size are required to validate the association.

Association of Genetic Variants With Response to Anti-Vascular Endothelial Growth Factor Therapy in Age-Related Macular Degeneration

Importance

Visual acuity (VA) outcomes differ considerably among patients with neovascular age-related macular degeneration (nAMD) treated with anti-vascular endothelial growth factor (VEGF) drugs. Identification of pharmacogenetic associations may help clinicians understand the mechanisms underlying this variability as well as pave the way for personalized treatment in nAMD.

Objective

To identify genetic factors associated with variability in the response to anti-VEGF therapy for patients with nAMD.

Design, Setting, and Participants

In this multicenter genome-wide association study, 678 patients with nAMD with genome-wide genotyping data were included in the discovery phase; 1380 additional patients with nAMD were genotyped for selected common variants in the replication phase. All participants received 3 monthly injections of bevacizumab or ranibizumab. Clinical data were evaluated for inclusion/exclusion criteria from October 2014 to October 2015, followed by data analysis from October 2015 to February 2016. For replication cohort genotyping, clinical data collection and analysis (including meta-analysis) was performed from March 2016 to April 2017.

Main Outcomes and Measures

Change in VA after the loading dose of 3 monthly anti-VEGF injections compared with baseline.

Results

Of the 2058 included patients, 1210 (58.8%) were women, and the mean (SD) age across all cohorts was 78 (7.4) years. Patients included in the discovery cohort and most of the patients in the replication cohorts were of European descent. The mean (SD) baseline VA was 51.3 (20.3) Early Treatment Diabetic Retinopathy Study (ETDRS) score letters, and the mean (SD) change in VA after the loading dose of 3 monthly injections was a gain of 5.1 (13.9) ETDRS score letters (ie, 1-line gain). Genome-wide single-variant analyses of common variants revealed 5 independent loci that reached a P value less than 10 × 10-5. After replication and meta-analysis of the lead variants, rs12138564 located in the CCT3 gene remained nominally associated with a better treatment outcome (ETDRS letter gain, 1.7; β, 0.034; SE, 0.008; P = 1.38 × 10-5). Genome-wide gene-based optimal unified sequence kernel association test of rare variants showed genome-wide significant associations for the C10orf88 (P = 4.22 × 10-7) and UNC93B1 (P = 6.09 × 10-7) genes, in both cases leading to a worse treatment outcome. Patients carrying rare variants in the C10orf88 and UNC93B1 genes lost a mean (SD) VA of 30.6 (17.4) ETDRS score letters (ie, loss of 6.09 lines) and 26.5 (13.8) ETDRS score letters (ie, loss of 5.29 lines), respectively, after 3 months of anti-VEGF treatment.

Conclusions and Relevance

We propose that there is a limited contribution of common genetic variants to variability in nAMD treatment response. Our results suggest that rare protein-altering variants in the C10orf88 and UNC93B1 genes are associated with a worse response to anti-VEGF therapy in patients with nAMD, but these results require further validation in other cohorts.

Exploring the Use of Molecular Biomarkers for Precision Medicine in Age-Related Macular Degeneration

Precision medicine aims to improve patient care by adjusting medication to each patient's individual needs. Age-related macular degeneration (AMD) is a heterogeneous eye disease in which several pathways are involved, and the risk factors driving the disease differ per patient. As a consequence, precision medicine holds promise for improved management of this disease, which is nowadays a main cause of vision loss in the elderly. In this review, we provide an overview of the studies that have evaluated the use of molecular biomarkers to predict response to treatment in AMD. We predominantly focus on genetic biomarkers, but also include studies that examined circulating or eye fluid biomarkers in treatment response. This involves studies on treatment response to dietary supplements, response to anti-vascular endothelial growth factor, and response to complement inhibitors. In addition, we highlight promising new therapies that have been or are currently being tested in clinical trials and discuss the molecular studies that can help identify the most suitable patients for these upcoming therapeutic approaches.

Changing vision: a review of pharmacogenetic studies for treatment response in age-related macular degeneration patients

Nonresponsiveness to age-related macular degeneration (AMD) treatments has become a growing concern in ophthalmology. Disparity among publications that have assessed pharmacogenetic (PGx) connections between AMD disease genes and treatments has delayed the implementation of PGx testing in AMD. We assessed all AMD PGx publications to identify the degree of agreement for publications within similar ethnic cohorts and worldwide, and the causes for differences in study outcomes. There are no accepted genotype–phenotype correlations, either within similar ethnic cohorts or worldwide. The diversity of measured outcomes, treatment protocols and statistical methods used may be causing this discrepancy. A universally accepted treatment protocol and the creation of agreed response group classification may bridge the gap between AMD PGx publications.

Association between CFH, CFB, ARMS2, SERPINF1, VEGFR1 and VEGF polymorphisms and anatomical and functional response to ranibizumab treatment in neovascular age-related macular degeneration

PURPOSE

We sought to determine if specific genetic single nucleotide polymorphisms (SNPs) influence vascular endothelial growth factor inhibition response to ranibizumab in neovascular age-related macular degeneration (AMD).

METHODS

A total of 403 Caucasian patients diagnosed with exudative AMD were included. After a three-injection loading phase, a pro re nata regimen was followed. Nine SNPs from six different genes (CFH, CFB, ARMS2, SERPINF1, VEGFR1, VEGF) were genotyped. Non-genetic risk factors (gender, smoking habit and hypertension) were also assessed. Patients were classified as good or poor responders (GR or PR) according to functional (visual acuity), anatomical (foveal thickness measured by OCT) and fluid criteria (fluid/no fluid measured by OCT).

RESULTS

Hypertension was the environmental factor with the strongest poor response association with ranibizumab in the anatomical measure after the loading phase (p = 0.0004; OR 3.7; 95% CI, 2.4-5.8) and after 12 months of treatment (p = 10^-5 ; OR 2.3; 95% CI, 1.5-3.4). The genetic variants rs12614 (CFB), rs699947 (VEGFA) and rs7993418 (VEGFR1) predisposed patients to a good response, while rs12603486 and rs1136287 (SERPINF1) were associated with a poor response. The protective genotype of rs800292 variant (CFH) was also associated with a poor anatomical response (p 0.0048).

CONCLUSION

All these data suggest that genetics play an important role in treatment response in AMD patients.

Association of the polymorphism Y402H in the CFH gene with response to anti-VEGF treatment in age-related macular degeneration: a systematic review and meta-analysis

To explore whether the complement factor H (CFH) polymorphism rs1061170/Y402H is associated with responsiveness to antivascular endothelial growth factor (VEGF) agents in age-related macular degeneration (AMD). We reviewed the English literature to examine the association between the polymorphism rs1061170/Y402H of the CFH gene and responsiveness to treatment with anti-VEGF drugs in AMD patients. A meta-analysis of eligible studies was also performed. Pooled odds ratios (ORs) and 95% CIs were estimated using Stata V.12.0. Statistical heterogeneity was measured using Q-statistic testing. Fourteen relevant studies including a total of 2963 AMD patients were eligible. In AMD patients without a treatment history, individuals carrying the rs1061170/Y402H TT genotype were more likely to achieve a better outcome (OR = 1.932, 95% CI = 1.125-3.317, p = 0.017) than those carrying the CC genotype. The polymorphism rs1061170/Y402H might be a genetic predictor of treatment response to anti-VEGF therapy in AMD patients. Further prospective research including a larger number of patients is needed to validate this finding.

Predictors of Response to Intravitreal Anti-Vascular Endothelial Growth Factor Treatment of Age-Related Macular Degeneration

PURPOSE

To identify factors that influence visual and anatomic response to treatment with intravitreal anti-vascular endothelial growth factor (VEGF) for neovascular age-related macular degeneration (AMD).

DESIGN

Observational cohort study.

METHODS

Seventy-two patients were included in this study. Best-corrected Snellen visual acuity (VA) and central foveal thickness measured on optical coherence tomography (OCT) at time of treatment and post-treatment follow-up visits were recorded. Associations between demographic, behavioral, and genetic risk factors and the 2 outcomes were analyzed using mixed-effects linear regression models. Two loci in complement factor H (CFH) were included in a risk score to determine the association between CFH risk and improvement in VA and central foveal thickness.

RESULTS

There was a small improvement in VA following anti-VEGF treatment (mean: 3.7 ± 3.0 letters), which was not statistically significant. Significant improvement in VA was observed for the nonrisk CFH Y402H genotype (P < .001) and for a low CFH risk score (P = .019). Regarding the outcome of change in central foveal thickness, improvement was noted in all genotype groups, but reduction after treatment was significantly higher in the low CFH risk score group (P = .033). A significant improvement in mean VA was seen among smokers (P < .001), but this relationship was not observed for central foveal thickness.

CONCLUSION

After anti-VEGF therapy, significant improvement in VA was observed for low-risk CFH genotypes and subjects with a low risk score. There was a statistically significant reduction in central foveal thickness overall, and subjects with a low CFH risk score improved more than the high-risk group.

A Validated Phenotyping Algorithm for Genetic Association Studies in Age-related Macular Degeneration

Age-related macular degeneration (AMD), a multifactorial, neurodegenerative disease, is a leading cause of vision loss. With the rapid advancement of DNA sequencing technologies, many AMD-associated genetic polymorphisms have been identified. Currently, the most time consuming steps of these studies are patient recruitment and phenotyping. In this study, we describe the development of an automated algorithm to identify neovascular (wet) AMD, non-neovascular (dry) AMD and control subjects using electronic medical record (EMR)-based criteria. Positive predictive value (91.7%) and negative predictive value (97.5%) were calculated using expert chart review as the gold standard to assess algorithm performance. We applied the algorithm to an EMR-linked DNA bio-repository to study previously identified AMD-associated single nucleotide polymorphisms (SNPs), using case/control status determined by the algorithm. Risk alleles of three SNPs, rs1061170 (CFH), rs1410996 (CFH), and rs10490924 (ARMS2) were found to be significantly associated with the AMD case/control status as defined by the algorithm. With the rapid growth of EMR-linked DNA biorepositories, patient selection algorithms can greatly increase the efficiency of genetic association study. We have found that stepwise validation of such an algorithm can result in reliable cohort selection and, when coupled within an EMR-linked DNA biorepository, replicates previously published AMD-associated SNPs.

Comparison of the Effectiveness and Prognostic Factors of Intravitreal Ranibizumab between Typical Neovascular Age-Related Macular Degeneration and Polypoidal Choroidal Vasculopathy over 24 Months of Follow-Up

PURPOSE

To compare the response to ranibizumab between patients with typical neovascular age-related macular degeneration (tAMD) and those with polypoidal choroidal vasculopathy (PCV), and to determine the predictors for the outcomes.

METHODS

Fifty-nine eyes from 59 consecutive patients (tAMD: 27 eyes, PCV: 32 eyes) were treated with three monthly ranibizumab injections followed by as-needed retreatment. Best-corrected visual acuity (BCVA) and morphological parameters were evaluated over 24 months of follow-up.

RESULTS

The mean BCVA in tAMD and PCV patients was significantly improved at 3 months (-0.22 and -0.09 logMAR units, respectively). The improvement in BCVA was sustained up to 24 months in tAMD (p = 0.01) but not in PCV patients. The significant predictor for good response to ranibizumab in tAMD patients was the improvement of BCVA at 3 months, whereas that in PCV patients was the anatomical resolution at 3 months.

CONCLUSIONS

Ranibizumab is an effective therapy for tAMD and PCV over 24 months. The predictors for good outcome might be different between tAMD and PCV.

Association of Genetic Variants with Polypoidal Choroidal Vasculopathy: A Systematic Review and Updated Meta-analysis

TOPIC

A systematic review and meta-analysis of the genetic association with polypoidal choroidal vasculopathy (PCV) and the genetic difference between PCV and neovascular age-related macular degeneration (nAMD).

CLINICAL RELEVANCE

To identify genetic biomarkers that are potentially useful for genetic diagnosis of PCV and for differentiating PCV from nAMD.

METHODS

We performed a literature search in EMBASE, PubMed, Web of Science, and the Chinese Biomedical Database for PCV genetic studies published before February 6, 2015. We then conducted a meta-analysis of all polymorphisms that had sufficient genotype/allele data reported in ≥2 studies and estimated the summary odds ratio (OR) and 95% confidence intervals (CIs) for PCV. We also compared the association profiles between PCV and nAMD, and performed a sensitivity analysis.

RESULTS

A total of 66 studies were included in the meta-analysis, involving 56 polymorphisms in 19 genes/loci. In total, 31 polymorphisms in 10 genes/loci (age-related maculopathy susceptibility 2 [ARMS2], high-temperature requirement factor A1 [HTRA1], complement factor H [CFH], complement component 2 [C2], CFB, RDBP, SKIV2L, CETP, 8p21, and 4q12) were significantly associated with PCV. Another 25 polymorphisms in 13 genes (ARMS2, HTRA1, C2, CFB, ELN, LIPC, LPL, ABCA1, VEGF-A, TLR3, LOXL1, SERPING1, and PEDF) had no significant association. Twelve polymorphisms at the ARMS2-HTRA1 locus showed significant differences between PCV and nAMD. The sensitivity analysis validated the significance of our analysis.

CONCLUSIONS

This study revealed 31 polymorphisms in 10 genes/loci that contribute to PCV susceptibility. Among them, ARMS2-HTRA1 also showed allelic diversity between PCV and nAMD. Our results confirm the gene variants that could affect the phenotypic expressions of PCV and nAMD.