Intravitreal bevacizumab (Avastin) for occult choroidal neovascularization in age-related macular degeneration

Bevacizumab in Wet AMD treatment: A tribute to the thirteen years of experience from the beginning of the anti-VEGF era in Romania

This study aimed to identify and describe anatomical and functional changes on short (1–3 months) and medium (6–12 months) term after intravitreal injections of bevacizumab (Avastin, Genentech) in patients with choroidal neovascularization (CNV) in the context of exudative form of age-related macular degeneration (AMD). We performed a retrospective, analytical, interventional study, based on a series of cases with exudative form of AMD, which also comprised a prospective component related to the inclusion and treatment of the patients with a very new interventional method for that time (2006) and the follow-up of the effects of intravitreal injection of bevacizumab (1.25 mg) therapy in three monthly doses for short (1–3 months) and medium (6–18 months) periods of time. The follow-up of these patients was made by determining visual acuity (VA) as best corrected visual acuity (BCVA) at baseline and at every visit, slit lamp examination with contact or noncontact lenses each time, and optical coherence tomography and/or angiofluorography, applied only for certain patients, at various times of the study. In total, 376 intravitreal injections were administered to 117 eyes of 96 patients. The VA improved in the assessment of 3 months in 77 eyes (66%), either subjective (by the patient) or objectively quantified (by the physician). In 40 eyes (34%), there was no change in VA. In patients for whom optical coherence tomography could be performed, a significant reduction of the macula's thickness was found. The use of bevacizumab in subretinal neovascular membrane treatment is effective and safe on short and medium term, with the improvement of BCVA and reduction of macular edema in a significant number of cases.

Real-world evidence of safety profile of intravitreal bevacizumab (Avastin) in an Indian scenario

PURPOSE

The purpose of this study was to evaluate the safety profile of intravitreal bevacizumab (Avastin) as an off-label pharmacotherapeutic agent for various ocular conditions.

METHODS

Retrospective analysis was carried out on 3806 injections of 1761 patients that were administered with intravitreal bevacizumab injection at a tertiary eye care center in India. The injections were administered on a pro re nata basis for various indications such as age-related macular degeneration (AMD), diabetic macular edema (DME), and retinal vein occlusion (RVO).

RESULTS

The mean age of the patients was 61.8 ± 11.59 years. A total of 59.2% of the patients were men and 40.8% women. The most common indications for which the injection was administered were DME (27.5%), AMD (26%), and branch RVO (12.3%). Among the ocular side effects, endophthalmitis was seen in three eyes (0.08%), retinal breaks in none of the eyes whereas 35 eyes had a rise in intraocular pressure (IOP) >21 mmHg (0.9%). Preexisting glaucoma was present in four eyes while remaining 31 eyes did not have any history of glaucoma. IOP rise was significantly more in eyes with preexisting glaucoma as compared to nonglaucomatous eyes (P = 0.04). No systemic adverse events were noted in our study population.

CONCLUSION

Our study provides real-world evidence regarding the safety profile of intravitreal bevacizumab (Avastin). These data suggest that bevacizumab is a safe and economical pharmacotherapeutic agent that can be administered for a variety of ocular disorders. Analyzing the safety of bevacizumab is necessary for a developing country like India as the majority of the population cannot afford the costly ranibizumab as compared to bevacizumab for ocular healthcare.

Systemic safety of intravitreal anti-vascular endothelial growth factor agents in age-related macular degeneration

PURPOSE OF REVIEW

The purpose of review is to summarize the literature addressing nonocular adverse events in patients with neovascular age-related macular degeneration treated with intravitreal vascular endothelial growth factor (VEGF) inhibitors and to present possible mechanisms of effect.

RECENT FINDINGS

The incidence of overall nonocular serious adverse events varied from 0 to 39.3% and nonocular adverse events ranged from 0 to 86.9%. Few studies have reported a significant association between use of intravitreal anti-VEGF agents and overall incidence of adverse events, stroke, myocardial infarction, nonocular hemorrhage and death, with overall greater concern in patients treated with bevacizumab. Additionally, history of stroke or other arterial thromboembolic event may be a risk factor for future stroke in patients treated with intravitreal anti-VEGF agents. Theories explaining the mechanisms of increased risk of nonocular adverse events secondary to anti-VEGF agent use surround the necessity of VEGF for the normal functioning of the endothelium and the damage incurred with use of anti-VEGF agents.

SUMMARY

Current data are insufficient to definitively conclude that intravitreal anti-VEGF agents are safe, although there is a trend toward an overall favorable systemic safety profile. Caution should be exerted in patients with a history of cardiovascular disease, as these patients may be at greater risk for nonocular serious adverse events.

Combined therapy (intravitreal bevacizumab plus verteporfin photodynamic therapy) versus intravitreal bevacizumab monotherapy for choroidal neovascularization due to age-related macular degeneration: a 1-year follow-up study

PURPOSE

To assess the efficacy and safety of combined intravitreal bevacizumab and low-fluency-rate photodynamic therapy (PDT) in the treatment of choroidal neovascularization (CNV) associated with age-related macular degeneration (AMD) and to compare it with intravitreal bevacizumab monotherapy.

METHODS

A total of 62 eyes of 62 patients with angiographic evidence of CNV were divided into 2 groups: the eyes of one group were treated with a combined therapy of 1 intravitreal bevacizumab injection (1.25 mg) and PDT within 7 days; the eyes of the other group received intravitreal bevacizumab monotherapy. Clinical evidence of complications, best-corrected visual acuity (BVCA) and fluorescein leakage were evaluated. Best-corrected visual acuity and optical coherence tomography (OCT) were tested monthly and followed for 12 months.

RESULTS

In the combined group the mean BCVA increased from 0.61 logMAR before the treatment to 0.54 logMAR at 12 months' follow-up. In the monotherapy group the mean BCVA increased from 0.65 logMAR to 0.60 logMAR at 12 months' follow-up. There was no significant difference in visual acuity outcomes between groups (P > 0.05). In the combined group the mean number of treatments was 1.19 per patient; in the monotherapy group, 5.31 per patient (P < 0.01).

CONCLUSIONS

Combined therapy appears to be an effective option for CNV associated with AMD treatment allowing a significant reduction of intravitreal injections.

Predictors of visual and anatomical outcomes for neovascular age-related macular degeneration treated with bevacizumab

The present study aimed to evaluate the predictive factors for visual and anatomical outcomes in neovascular age-related macular degeneration (AMD) patients treated with intravitreal bevacizumab (IVB). A total of 113 patients with neovascular AMD received IVB treatment. The best corrected visual acuity (BCVA), central retinal thickness (CRT) and total macular volume (TMV) were assessed before the injection, and at 1, 2, 3 and 9 months after surgery. Changes in BCVA and these optical coherence tomography (OCT) outcomes from baseline were compared, and independent predictors were evaluated by logistic regression models. During the treatment, logarithm of the minimum angle of resolution (logMAR) significantly decreased from 1.12 to 0.83, and reductions in OCT parameters were earlier and larger. Baseline BCVA was associated with the changes in BCVA and CRT, whereas baseline OCT features significantly affected their own changes. Larger baseline logMAR and OCT features were more likely to experience a greater proportion of ≥50 µm reduction in CRT (P<0.05). The BCVA decreases were positively associated with the reductions in CRT (r=0.34, P<0.01) and TMV (r=0.41, P<0.01). Among patients with neovascular AMD, IVB resulted in earlier significant decreases in TMV and CRT, suggesting that these OCT anatomical outcomes may be considered as more sensitive responders to evaluate the treatment effects of bevacizumab.

Experimental histopathological study on retinal and renal cellular response to intravitreous antiangiogenic drugs

AIM

To evaluate histopathological retinal and renal response after one single dose of intravitreous injection of antiangiogenic drugs ranibizumab and bevacizumab in rats.

METHODS

Experimental study in 60d of life adults Wistar rats. Ten animals were included. Group 1 included 5 animals that were injected with 1 µL ranibizumab 1.25 mg in the right eye and with 1 µL of balanced salt solution (BSS) in the left eye, as control; Group 2 included 5 animals that were injected with 1 µL of bevacizumab in the right eye and with 1 µL of BSS in the fellow eye. All injections were performed with Hamilton syringes. After 15d of the interventions, all animals were sacrificed in CO2 chamber. Both eyes were enucleated and one kidney was removed, fixed and embedded in paraffin for histopathological analysis by optic microscopy. For statistical purposes the initial expected abnormal histopathological responses were defined as 0%.

RESULTS

Atypical histopathological retinal response was detected in 2 eyes injected with ranibizumab (40%) as well as in 2 control eyes in group 1. Same was detected in 1 eye injected with bevacizumab (20%) as well as in 1 control eye, in group 2. The noted atypical findings were lymphocytes and eosinophils in the vitreous posterior cavity and mild retinal inflammatory reaction with ganglion cell layer edema but without clinical significance. No atypical histopathological renal response was detected.

CONCLUSION

Unexpected atypical histopathological retinal response without clinical significance was observed in 3 eyes injected with antiangiogenic drugs (2 in group 1 and 1 in group 2) as well as in 3 control eyes (2 in group 1 and 1 in group 2). No atypical renal response was detected suggesting no extra ocular involvement of the intravitreous injected antiangiogenic drugs.

Predictors of visual response to intravitreal bevacizumab for treatment of neovascular age-related macular degeneration

Purpose. To identify the predictors of visual response to the bevacizumab treatment of neovascular age-related macular degeneration (AMD). Design. A cohort study within the Neovascular AMD Treatment Trial Using Bevacizumab (NATTB). Methods. This was a multicenter trial including 144 participants from the NATTB study. Visual outcomes measured by change in visual acuity (VA) score, proportion gaining ≥15 letters, and change in central retinal thickness (CRT) were compared among groups according to the baseline, demographic, and ocular characteristics and genotypes. Results. Mean change in the VA score was 9.2 ± 2.3 SD letters with a total of 46 participants (31.9%) gaining ≥15 letters. Change in median CRT was −81.5 μm. Younger age, lower baseline VA score, shorter duration of neovascular AMD, and TT genotype in rs10490924 were significantly associated with greater VA score improvement (P = 0.028, P < 0.001, P = 0.02, and P = 0.039, resp.). Lower baseline VA score and TT genotype in rs10490924 were significantly associated with a higher likelihood of gaining ≥15 letters (P = 0.028, and P = 0.021, resp.). Conclusions. Baseline VA and genotype of rs10490924 were both important predictors for visual response to bevacizumab at 6 months. This trial is registered with the Registration no. NCT01306591.

Prevention of VEGF-induced growth and tube formation in human retinal endothelial cells by aldose reductase inhibition

OBJECTIVE

Since diabetes-induced vascular endothelial growth factor (VEGF) is implicated in retinal angiogenesis, we aimed to examine the role of aldose reductase (AR) in VEGF-induced human retinal endothelial cells (HREC) growth and tube formation.

MATERIALS AND METHODS

HRECs were stimulated with VEGF and cell-growth was determined by MTT assay. AR inhibitor, fidarestat, to block the enzyme activity and AR siRNA to ablate AR gene expression in HREC were used to investigate the role of AR in neovascularization using cell-migration and tube formation assays. Various signaling intermediates and angiogenesis markers were assessed by Western blot analysis. Immuno-histochemical analysis of diabetic rat eyes was performed to examine VEGF expression in the retinal layer.

RESULTS

Stimulation of primary HREC with VEGF caused increased cell growth and migration, and AR inhibition with fidarestat or ablation with siRNA significantly prevented it. VEGF-induced tube formation in HREC was also significantly prevented by fidarestat. Treatment of HREC with VEGF also increased the expression of VCAM, AR, and phosphorylation and activation of Akt and p38-MAP kinase, which were prevented by fidarestat. VEGF-induced expression of VEGFRII in HREC was also prevented by AR inhibition or ablation.

CONCLUSIONS

Our results indicate that inhibition of AR in HREC prevents tube formation by inhibiting the VEGF-induced activation of the Akt and p38-MAPK pathway and suggest a mediatory role of AR in ocular neovascularization generally implicated in retinopathy and AMD.

Cost-utility analysis of bevacizumab versus ranibizumab in neovascular age-related macular degeneration using a Markov model

OBJECTIVE

To evaluate the cost-effectiveness of intravitreal bevacizumab to ranibizumab in patients with neovascular age-related macular degeneration (AMD).

METHODS

A cost-utility analysis using a Markov model was performed to evaluate incremental cost-effectiveness ratio [ICER, $US per quality-adjusted life year (QALY) gained] between bevacizumab and ranibizumab from a US payer perspective. Transition probabilities for ranibizumab and bevacizumab were extrapolated from published studies and local institutional data. Utility values, likewise, were obtained from another published study. Mortality rates were determined from the Centers for Disease Control 2003 Life Tables. Resource utilization and total direct costs were estimated using the Centers for Medicare and Medicaid Services and the Veterans Affairs Decision Support System. A hypothetical cohort of 1000 patients was simulated through the model for 20 years. Sensitivity analyses were performed using univariate and probabilistic sensitivity analysis (PSA) on all costs, transition probabilities and utility values. An acceptability curve was generated to illustrate the cost-effectiveness probability of bevacizumab to ranibizumab with increasing willingness-to-pay (WTP).

RESULTS

The cost-effectiveness ratios (CER) for bevacizumab and ranibizumab were $1405 per QALY and $12,177 per QALY, respectively. The ICER for bevacizumab was dominant compared to ranibizumab. The base-case CER was sensitive to drug costs of the study medications with a breakeven point of $44 for ranibizumab and $2666 for bevacizumab. PSA revealed a 95% probability of bevacizumab being more cost-effective than ranibizumab at a WTP of $50,000 per QALY gained.

CONCLUSION

Based on a WTP defined at $50,000 per QALY gained, bevacizumab was cost-effective versus ranibizumab 95% of the time because of lower acquisition costs and increased efficacy.

Intravitreal bevacizumab alone versus in combination with photodynamic therapy for the treatment of neovascular maculopathy in patients aged 50 years or older: 1-year results of a prospective clinical study

PURPOSE

To compare the outcomes of treatment with intravitreal bevacizumab alone (BEVA group) or in combination with photodynamic therapy (PDT) (COMB group), in patients aged at least 50 years with neovascular maculopathy.

METHODS

Forty-one patients with neovascular age-related macular degeneration (AMD) (n = 31) or polypoidal choroidal vasculopathy (PCV) (n = 10) were randomized to either the BEVA group (n = 18) or the COMB group (n = 23). A total of three intravitreal bevacizumab injections (1.25 mg/0.05 ml) were given at 6-week intervals. In the COMB group, PDT was included near the time of one injection. Patients underwent best-corrected visual acuity (BCVA) measurement and optical coherence tomography (OCT) at every visit. Fluorescein angiography and indocyanine green angiography were repeated every 3 months.

RESULTS

Overall BCVA (p = 0.001) and central foveal thickness (CFT) (p < 0.001) measured by OCT improved significantly at 12 months, and there was no between-group difference in BCVA or CFT between the BEVA and COMB groups. Whereas AMD patients showed significant improvement in BCVA (p = 0.001) and CFT (p = 0.004), PCV patients failed to improve. The effect of bevacizumab alone on neovascular AMD was similar to that of combination therapy, when measured by both BCVA and CFT. The total number of bevacizumab injections was not reduced when PDT was given, either among all patients or in a subgroup of naïve patients (p > 0.05). No serious complication was noted.

CONCLUSION

The results of our 12-month prospective study indicate that intravitreal bevacizumab alone has similar efficacy and safety to bevacizumab plus PDT for treatment of patients with neovascular AMD, even treatment-naïve patients. The addition of PDT did not assist in reducing the required total number of bevacizumab injections.

Bevacizumab injection in patients with age-related macular degeneration associated with poor initial visual acuity

Purpose. To evaluate functional and anatomic effects of intravitreal bevacizumab in patients with neovascular AMD and initial low visual acuity. Methods. Retrospective case series of 38 eyes with neovascular AMD and initial visual acuity of 20/200 or less, treated with intravitreal bevacizumab injection. Results. Mean followup was 14.1 months ±  7.1 (range: 5 to 24 months). Mean logMAR vision at baseline was 1.38 logMAR ±  0.33, at 6 months was 1.14 logMAR ±  0.37 (P = 0.001) and at 12 months was 1.22 logMar ±  0.33 (P = 0.004). Mean baseline central retinal thickness was 431 μm ±  159.7 at 6 months was 293.43 μm  ±  122.79 (P = 10⁻⁴) and at 12 months was 293.1 μm  ±  130 (P = 0.004). Visual acuity improved in both patients with or without prior PDT treatment. Conclusions. Intravitreal bevacizumab injection may increase the chance of visual acuity gain in neovascular AMD even in cases with initial low visual acuity.

Lasting controversy on ranibizumab and bevacizumab

Vascular endothelial growth factor (VEGF), an important angiogenic factor that is able to stimulate the proliferation and migration of endothelial cells, is the best-studied hallmark of angiogenesis. Neovascularization is a major cause of age-related macular degeneration (AMD) which is a leading cause of blindness in the elderly population. Specific molecular inhibitors of VEGF have been proved to be useful in the treatment of AMD. Ranibizumab and Bevacizumab are structurally similar to anti-VEGF drugs in the treatment of AMD. Many studies have indicated that Ranibizumab and Bevacizumab are of roughly equal short-term efficacy and safety, Bevacizumab is an attractive alternative to Ranibizumab due to its lower cost. However, only Ranibizumab has received Food and Drug Administration (FDA) approval for the treatment of macular degeneration. More multicenter clinical trials are required to compare the relative efficacy and safety of these two drugs and some progress has been achieved. This review discusses the clinical effectiveness, safety, cost and other practical implications of Ranibizumab and Bevacizumab.

Efficacy of 12-month treatment of neovascular age-related macular degeneration with intravitreal bevacizumab based on individually determined injection strategies after three consecutive monthly injections

PURPOSE

To report the results of intravitreal treatment with bevacizumab in neovascular age-related macular degeneration (AMD) after a loading dose (LD) of three monthly injections followed by an optical coherence tomography (OCT)-guided strategy, based on best-corrected visual acuity (VA) and number of injections required over 1 year.

METHODS

A series of consecutive cases of 149 eyes of 147 patients received three or more intravitreal injections of bevacizumab (1.25 mg) for neovascular AMD over a 1-year period. The patients underwent ophthalmological examinations: measurement of the VA, fluorescein angiography, dilated fundus examination at baseline; VA, OCT and dilated fundus examination at monthly follow-up visits. Repeated injections were given each month for the first 3 months (LD); thereafter, injections were only administered if leakage or macular oedema were present.

RESULTS

Mean baseline VA was 51 ± 14 letters, which improved to 58 ± 15 letters (p < 0.0001; n = 149) at first evaluation (15 ± 2 weeks), 59 ± 15 letters (p < 0.0001; n = 143) at second evaluation (25 ± 2 weeks) and 57 ± 16 letters (p < 0.0001; n = 132) at third evaluation (51 ± 3 weeks). The baseline mean central retinal thickness (344.6 μm) and total macular volume (8.6 mm(3) ) decreased at first evaluation, to 219.0 μm (p < 0.0001) and 7.2 mm(3) (p < 0.0001), respectively. The mean number of injections per patient treated for 1 year was 5.1 (range 3-9). No systemic side-effects were noted.

CONCLUSION

Treatment of neovascular AMD with intravitreal bevacizumab administered in LD of three monthly injections and followed by an OCT-guided strategy provides functional and anatomical improvements for up to 1 year.

How the comparison of age-related macular degeneration treatments trial results will impact clinical care

PURPOSE

To provide a perspective on the impact of the Comparison of Age-related Macular Degeneration Treatments Trial (CATT) on future clinical practices.

DESIGN

Interpretation of trial outcomes relative to clinical use of neovascular age-related macular degeneration (AMD) treatments, assessment of the influence of study design and execution on results, and review of unanalyzed safety data in the online supplement.

METHODS

Expert opinion.

RESULTS

The CATT study supports the selection of either ranibizumab or bevacizumab for treatment of AMD based on factors other than efficacy, such as cost, because monthly administration of bevacizumab was noninferior to the reference treatment of monthly ranibizumab in improving visual acuity at 1 year. Visual acuity results for bevacizumab as needed were inconclusive for noninferiority relative to monthly administration of either drug. The secondary outcome of decrease in thickness at the foveal center as measured by time-domain optical coherence tomography significantly favored the monthly ranibizumab group vs the bevacizumab-as-needed group but is more difficult to interpret as it did not correlate with visual acuity and is less appropriate for a noninferiority design. Bevacizumab groups had a statistically higher observed risk of serious adverse events; however, scrutiny of the online supplements shows similar numbers of cardiac and neurologic events in bevacizumab and ranibizumab users. Information regarding fellow eye treatment with anti-VEGF agents was not given.

CONCLUSIONS

CATT provides the first level I evidence for bevacizumab in a large number of patients with neovascular AMD. The trial supports use of either drug as primary therapy and suggests that modification of monthly dosing regimens is feasible. A difference in cardiovascular safety between the 2 drugs was not apparent on inspection of the supplementary safety data.

Treatment of age-related macular degeneration: focus on ranibizumab

Ranibizumab, a humanized antigen-binding fragment (Fab) that binds all isoforms of VEGF-A, significantly slows down loss of vision and causes significant visual improvement in many patients with choroidal neovascularization (CNV) due to exudative age-related macular degeneration (AMD). These benefits of intravitreal ranibizumab apply to all angiographic subtypes of neovascular AMD and across all lesion sizes when the drug is injected at monthly intervals as shown in two pivotal phase III trials (ANCHOR and MARINA). The results from the PrONTO study suggest that less frequent treatment with ranibizumab through a variable dosing regimen dependent on optical coherence tomography (OCT) findings is a treatment option that results in comparably favorable visual outcomes. Currently, it is unclear whether combination therapy of ranibizumab with photodynamic therapy (PDT) provides any significant advantage over ranibizumab monotherapy (FOCUS trial); however, the combination of PDT and ranibizumab may decrease the need for frequent retreatment. This question will be addressed in the SUMMIT trial. Therapy with ranibizumab is generally very well tolerated with a low rate of seriously adverse ocular events or systemic side-effects. The advent of vascular endothelial growth factor (VEGF) inhibitors has revolutionized the therapy of neovascular AMD. Ranibizumab at the moment appears to be the most effective approved treatment for neovascular AMD.

Intravitreal bevacizumab has initial clinical benefit lasting eight weeks in eyes with neovascular age-related macular degeneration

Purpose

To determine whether the effect of a single initial intravitreal injection of bevacizumab for neovascular age-related macular degeneration (AMD) persists for 8 weeks.

Methods

We reviewed the records of 25 consecutive patients with neovascular AMD treated with intravitreal bevacizumab. Patients were included (n = 15) if follow up data were available from 4 and 8 week visits after a single initial injection. Additionally, optical coherence tomography (OCT) images were graded qualitatively in a masked fashion by a single reader.

Results

Baseline mean visual acuity was 20/200, improving to 20/125 at 4 weeks (p = 0.0153) and 20/100 at 8 weeks (p = 0.0027). Mean central retinal thickness was 316 ± 107 μm at baseline and decreased to 223 ± 70 μm and 206 ± 45 μm at 4 and 8 weeks post-injection, respectively (p = 0.0003 and 0.0005). By masked OCT grading, macular fluid was resolved in 10/15 (66.7%) and 11/15 (73.3%) eyes at 4 and 8 weeks, respectively, and 3/15 (20%) eyes had continued reduction in residual macular fluid between 4 and 8 weeks.

Conclusions

A single initial bevacizumab injection has persistent clinical benefit lasting 8 weeks in most eyes with neovascular AMD. Results of prospective randomized studies are needed before changes in treatment regimens can be recommended.

Pharmacotherapy for neovascular age-related macular degeneration: an analysis of the 100% 2008 medicare fee-for-service part B claims file

PURPOSE

To describe the usage patterns of pharmacological treatments for neovascular age-related macular degeneration (AMD) in Medicare fee-for-service beneficiaries.

DESIGN

Retrospective review of all Medicare fee-for-service Part B claims for neovascular AMD during 2008.

METHODS

Medicare beneficiaries having undergone treatment were identified. The data collected for each visit for a given beneficiary included age, race, gender, Medicare region, state/zip code of residence, date of visit, whether or not the beneficiary had a treatment, the type and amount of drug, and dollars paid by Medicare. The main outcome measures were the number and rate of treatments, the types of drugs used for treatment, and the payments for these drugs.

RESULTS

Of the 222 886 unique beneficiaries, 146 276 (64.4%) received bevacizumab and 80 929 (35.6%) received ranibizumab. A total of 824 525 injections were performed with 480 025 injections of bevacizumab (58%) and 336 898 injections of ranibizumab (41%). National rates of injections per 100 000 fee-for-service Part B Medicare beneficiaries for bevacizumab and ranibizumab were 1506 and 1057, respectively. Total payments by Medicare were $20 290 952 for bevacizumab and $536 642 693 for ranibizumab. In 39 out of 50 states, the rate of injection was higher for bevacizumab compared with ranibizumab.

CONCLUSIONS

In 2008, bevacizumab was used at a higher rate than ranibizumab for the treatment of neovascular AMD. Even though bevacizumab accounted for 58% of all injections, Medicare paid $516 million more for ranibizumab than bevacizumab. These data suggest that despite its off-label designation, intravitreal bevacizumab is currently the standard-of-care treatment for neovascular AMD in the United States.

Randomised clinical trial of intravitreal Avastin vs photodynamic therapy and intravitreal triamcinolone: long-term results

PURPOSE

To compare 1-year functional and anatomic outcomes of intravitreal bevacizumab (IVB) and photodynamic therapy plus intravitreal triamcinolone (PDT+IVTA) combination in patients with neovascular age-related macular degeneration (AMD).

METHODS

In this prospective, randomised, controlled clinical trial, 28 patients were included. All patients were randomised 1 : 1 to 0.04 ml/1 mg of IVB or PDT plus same day 0.1 ml/4 mg IVTA (PDT+IVTA). Follow-up examinations were performed in monthly intervals in IVB group and every 3 months in PDT+IVTA group. Main outcomes were change in mean visual acuity (VA), mean central retinal thickness (CRT) and the mean number of treatments.

RESULTS

At month 12, mean VA improved to a 1.5-line gain in IVB group, and lost three letters in PDT+IVTA group (P=0.02). Mean CRT was reduced from 357 microm at baseline to 244 microm at month 12 in IVB group and from 326 microm to 254 microm, respectively, in PDT+IVTA group (P=0.8). The mean number of treatments was 6.8 in the IVB group vs 1.9 in the PDT+IVTA group. No significant local or systemic safety concerns were detected during follow-up time.

CONCLUSIONS

Patients treated with IVB showed a significant better VA outcome compared with the PDT+IVTA group despite the fact that both modalities showed equal potency in reducing CRT during a 12-month period.

Intravitreal bevacizumab for exudative age-related macular degeneration: effect on different subfoveal membranes

PURPOSE

The purpose of this study was to assess an association between specific types of subfoveal neovascularization and the change in visual acuity after intravitreal injections of bevacizumab (F. Hoffmann-La Roche AG, Basel, Switzerland) as treatment for exudative age-related macular degeneration.

METHODS

This retrospective clinical interventional comparative study included 307 patients (378 eyes) who received 3 consecutive intravitreal injections of bevacizumab at intervals of 2 months each. The study group was divided into eyes with a predominantly or purely classic type of subfoveal neovascular membrane (n = 81), those with an occult type with or without minimally classic subfoveal neovascularization (n = 232), and eyes with a detachment of the retinal pigment epithelium (n = 65).

RESULTS

The gain in best-corrected visual acuity did not vary significantly among the 3 subgroups at 2 months after baseline (P = 0.35 and P = 0.27), at 4 months after baseline (P = 0.63 and P = 0.56), or at the final follow-up at 7 months after baseline (P = 0.85 and P = 0.76). In multivariate linear regression analysis, the gain in best-corrected visual acuity at the final follow-up was significantly associated with the best-corrected visual acuity at baseline (P < 0.001). It was not significantly associated with age (P = 0.61), sex (P = 0.12), self-reported diabetes (P = 0.79), lens status (P = 0.84), or type of subfoveal neovascularization (P = 0.53).

CONCLUSION

After an intravitreal application of bevacizumab given as therapy for exudative age-related macular degeneration at 2-month intervals, the patient's gain in visual acuity did not depend on the type of the subfoveal neovascular membranes.

Bevacizumab vs ranibizumab for age-related macular degeneration: 1-year outcomes of a prospective, double-masked randomised clinical trial

PURPOSE

To report 1-year visual and anatomic outcomes of a prospective, double-masked randomised clinical trial comparing bevacizumab with ranibizumab for the treatment of age-related macular degeneration (AMD).

METHODS

Patients who met inclusion criteria were randomised 2 : 1 to bevacizumab or ranibizumab. All subjects and investigators (except for the pharmacist responsible for study assignments) were masked to treatment arms. Visual acuity was taken on Early Treatment Diabetic Retinopathy Study chart. Patients were given either bevacizumab or ranibizumab every month for the first 3 months, followed by an optical coherence tomography-guided, variable-dosing treatment schedule. Main outcomes measured included visual acuity, foveal thickness, and total number of injections over the 1-year treatment period.

RESULTS

In total, 15 patients received bevacizumab and 7 patients received ranibizumab. The average pre-operative visual acuity was 34.9 letters in the bevacizumab group, and 32.7 letters in the ranibizumab group. At 1-year follow-up, mean vision was 42.5 letters in the bevacizumab group, and 39.0 letters in the ranibizumab group. Two-tailed t-test failed to showed statistical significance between the two groups (P=0.5). Patients in the bevacizumab group underwent an average of eight injections, whereas patients in the ranibizumab group underwent a mean of four injections (P=0.001).

CONCLUSION

The 1-year outcomes of a prospective, double-masked, randomised clinical trial comparing bevacizumab with ranibizumab failed to show a difference in visual and anatomic outcomes between the two treatments for choroidal neovascularisation in AMD. Total injections given over the treatment period were significantly different between the two groups. Further studies with larger sample sizes are warranted.

Retrospective study of an as required dosing regimen of intravitreal bevacizumab in neovascular age-related macular degeneration in an Australian population

PURPOSE

To investigate the efficacy of intravitreal bevacizumab for the treatment of neovascular age-related macular degeneration (AMD) using an as required dosing regimen.

METHODS

A retrospective study of 210 patients (231 eyes) with choroidal neovascularization resulting from neovasacular AMD. Patients were treated with 1.25 mg intravitreal bevacizumab at a vitreoretinal practice in Adelaide, South Australia. Patients were followed up at 2-4 weeks and then at 1-month intervals; repeat injections were offered in the event of recurrence. Recurrence was defined as either a decrease of best-corrected visual acuity or an increase in macular oedema, subretinal fluid or intraretinal fluid on optical coherence tomography, after complete or partial resolution in previous follow-up visits. Patient data were collected for 12 months of follow up or until the patient's treatment was changed to ranibizumab.

RESULTS

Significant improvement in visual acuity and central retinal thickness was demonstrated at 1 month with an improvement of vision from logMAR equivalent 0.76 to 0.68 (P < 0.001) and a decrease of central retinal thickness from 306 µm to 244 µm (P < 0.001). This overall improvement was continued throughout the 12-month follow-up period; however, follow up was poor with 12-month data available for only a small number of patients (7.8%). Ocular and systemic side-effects were rare at 3.5% and 0.4%, respectively.

CONCLUSION

Eyes with neovascular AMD treated with intravitreal bevacizumab for up to 12 months had significant functional and anatomical improvement. Further studies need to confirm the long-term safety and efficacy of this treatment.

Intravitreal bevacizumab (Avastin) vs. ranibizumab (Lucentis) for the treatment of age-related macular degeneration: a systematic review

PURPOSE OF REVIEW

We conducted a systematic review to evaluate whether the existing evidence justifies the intravitreal use of bevacizumab in comparison to ranibizumab in age-related macular degeneration.

RECENT FINDINGS

Compared with photodynamic therapy, bevacizumab shows a relative improvement in visual acuity that is of similar size as in the comparison of ranibizumab with photodynamic therapy (relative improvement from 30 to 35%). However, this finding is based on one randomized controlled trial including less than 50 patients treated with bevacizumab. Also, nothing is known about long-term (>12 months) improvements in visual acuity and optimal treatment intervals for bevacizumab.Regarding safety, the published literature indicates that ocular and systemic adverse effects are less frequent under bevacizumab than ranibizumab treatment. But the validity of this finding is strongly limited by inadequate reporting, an unsystematic evaluation of adverse effects and short follow-up times in studies evaluating bevacizumab.

SUMMARY

Given the lack of controlled data, the widespread off-label use of bevacizumab is not justified in clinical practice. On the other hand, a major challenge in the management of patients who require repeated antivascular endothelial growth factor injections is the high cost of ranibizumab. This dilemma underlines the need for head-to-head studies comparing both vascular endothelial growth factor antibodies, or, at least, well conducted randomized controlled trials evaluating intravitreal bevacizumab.

Antiangiogenic drugs in the management of ocular diseases: Focus on antivascular endothelial growth factor

Age-related macular degeneration (AMD) complications are the leading cause of severe vision loss among the aging population in the many western countries. The introduction of molecular inhibitors of vascular endothelial growth factor (VEGF), such as pegaptanib, ranibizumab, and bevacizumab, as treatments for wet AMD has provided new hope for affected patients. Now we have these treatment options, which have the possibility to improve or maintain visual acuity for patients suffering from AMD. The treatment needs to be optimized and this is in progress. Based on emerging evidence, adopting a variable VEGF inhibitor-dosing strategy guided by visual acuity assessment and optical coherence tomography are now being tried to reduce the frequency of injections. VEGF inhibitors in combination with photodynamic therapy are another way to optimize treatment. Physicians are waiting for new guidelines for the management of AMD and the results of current and upcoming trials systematically addressing these issues will be expected to provide it.

Intravitreal bevacizumab for treatment-naive patients with subfoveal occult choroidal neovascularization secondary to age-related macular degeneration: a 12-month follow-up study

PURPOSE

The aim of this study was to assess the 12-month efficacy of intravitreal bevacizumab (IVB) injection for occult choroidal neovascularization secondary to age-related macular degeneration.

METHODS

In this retrospective, interventional case series, 68 treatment-naïve patients with age-related macular degeneration, affected by subfoveal occult choroidal neovascularization showing recent disease progression, were monitored during the IVB protocol. The patients received 1 initial IVB injection (1.25 mg/0.05 mL), and they underwent further retreatment on a monthly basis only when necessary, according to a standardized as-required regimen, until no significant signs of choroidal neovascularization activity were present. Main outcome measures were the modifications in best-corrected visual acuity and in central retinal thickness measured by optical coherence tomography.

RESULTS

With respect to baseline, at the 12-month check, mean best-corrected visual acuity increased from 0.82 to 0.45 logMAR (P < 0.01) and mean central retinal thickness decreased from 517.0 microm to 306.5 microm (P < 0.01). To achieve these benefits, the required mean IVB number was lowered from 3.87 in the first 6 months to 1.085 in the second 6 months. A better final best-corrected visual acuity was correlated with greater best-corrected visual acuity (P < 0.005) and lesser central retinal thickness (P < 0.05) at baseline.

CONCLUSION

In patients with age-related macular degeneration complicated by progressive occult choroidal neovascularization, first-line IVB administration represents a useful therapeutic option, especially considering its lower cost in comparison with other antiangiogenic drugs.

Bevacizumab vs ranibizumab for age-related macular degeneration: early results of a prospective double-masked, randomized clinical trial

PURPOSE

To report early outcomes of a prospective, double-masked, controlled trial comparing bevacizumab (Avastin; Genentech Inc, South San Francisco, California, USA) to ranibizumab (Lucentis; Genentech Inc) for the treatment of age-related macular degeneration.

DESIGN

Prospective, double-masked, randomized clinical trial.

METHODS

This is a single-center, randomized clinical trial at the Boston Veterans Affairs Healthcare System. Patients who met inclusion criteria were randomized 2:1 to bevacizumab or ranibizumab. Each patient contributed 1 eye to the study. All subjects and investigators (except for the pharmacist responsible for study assignments) were masked to treatment arms. Visual acuity (VA) was checked on Early Treatment Diabetic Retinopathy Study (ETDRS) chart. Patients were given either bevacizumab or ranibizumab every month for the first 3 months, followed by optical coherence tomography-guided, variable-dosing schedule. Main outcomes measured were VA and foveal thickness.

RESULTS

Twenty patients completed the 6-month follow up. Thirteen patients received bevacizumab and 7 patients received ranibizumab. No subjects in either group lost more than 15 letters on ETDRS chart. The average preoperative VA was 31.6 letters in the bevacizumab group and 30.4 letters in the ranibizumab group. At 6 months follow-up, mean vision was 46.4 letters in the bevacizumab group and 37.4 letters in the ranibizumab group. Two-tailed ttest failed to show statistical significance between the two groups. Patients in the bevacizumab group underwent an average of 5 injections, while patients in the ranibizumab group underwent a mean of 4 injections.

CONCLUSION

Early results of a head-to-head, randomized, double-masked, prospective, single-center controlled trial between bevacizumab and ranibizumab show no difference in efficacy between the two treatments for choroidal neovascularizaton in the treatment of age-related macular degeneration. As this study conveys results of a small number of patients, further studies with larger sample sizes are needed in order to establish statistical significance.

Efficacy of intravitreal bevacizumab (Avastin) therapy for early and advanced neovascular age-related macular degeneration

PURPOSE

To evaluate the safety and efficacy of intravitreal bevacizumab therapy for early and advanced neovascular age-related macular degeneration (ARMD).

METHODS

A consecutive series of eyes with neovascular ARMD treated with monthly intravitreal injections of bevacizumab (1.25 mg/0.05 ml) as long as there was evidence of activity on fluorescein angiography (FA) and optical coherence tomography (OCT) was included and observed for 6 months. For further analysis they were assigned to either an early (untreated/newly diagnosed) or an advanced (predominantly fibrotic/pre-treated) ARMD group. We examined distance visual acuity (VA) with Early Treatment Diabetic Retinopathy Study (ETDRS) charts and central retinal thickness with OCT, as well as lesion size and safety aspects.

RESULTS

Forty-four patients (44 eyes) were enrolled (21 early lesions, 23 advanced lesions). Mean VA changed from 0.74 logMAR at baseline to 0.68 logMAR at month 6 (P = 0.01). Improvement in VA was statistically significant only in eyes with early lesions (n = 21) from month 1 (P = 0.015) up to month 6 (P = 0.03). The changes in central retinal thickness (CRT) (P < 0.001) and total lesion size (P < 0.001) were significant in both groups (early and advanced) at all time-points during follow-up. No significant ocular or systemic adverse effects were observed.

CONCLUSION

Intravitreal bevacizumab was tolerated well by our patients and we did not identify any apparent short-term safety concerns. We observed stabilization in VA overall, with significant improvement in the early lesion group.

Intravitreal bevacizumab (Avastin) for age-related macular degeneration: a critical analysis of literature

PURPOSE

The current medical environment demands that quality health care is delivered at an affordable cost through the use of objective, unbiased clinical data. This study was undertaken to review the current literature on bevacizumab for age-related macular degeneration and its value in determining best clinical practice.

METHODS

Randomised controlled trials (RCTs) and observational studies that met the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) criteria were identified from the current literature for further analysis. Data concerning treatment dosing regimens, response to treatment, complications, and factors influencing outcome and safety were extracted and compiled into a database.

RESULTS

As of January 2009, there were 5 RCTs that compared the outcomes of bevacizumab to other treatment options and 50 studies that met the STROBE criteria with similar visual and anatomical outcomes between RCTs and observational studies. Although the doses and dosing frequencies varied between the studies, the mean gain in vision at 3 months was +7.76+/-5.4 ETDRS letters (range +2 to +14.4); an effect that was maintained at 6 months in studies with longer follow-up. Predominantly classic lesions were the most responsive of all lesion subtypes. The complication profiles/rates were similar to those reported with other anti-vascular endothelial agents.

CONCLUSIONS

There is sufficient scientific and statistical evidence to advocate the effective use of OCT-guided administration of intravitreal bevacizumab for neovascular AMD. This is reflected in our study outcome measures that are comparable to findings published from recent well-conducted RCTs on intravitreal ranibizumab at the same time point.

Bevacizumab (Avastin) for the treatment of ocular disease

The use of intravitreal bevacizumab (Avastin) has greatly expanded since its introduction into ophthalmic care 3 years ago. A PubMed search on 1 August 2008 revealed 51 ocular disease processes that have been treated with bevacizumab. The majority of publications consist of case reports or retrospective case series and their number is increasing quickly. It is important to collate the experiences gained to date to properly inform our clinical decision making and improve the design of future clinical trials. Current studies cannot easily be combined in a meta-analysis given the lack of standardized data and the wide variety of disorders studied in small numbers. This paper will describe the attempted uses of intravitreal bevacizumab and its efficacy for each ocular disease in addition to discussing safety. Comments regarding appropriate use of this treatment are based on our current level of knowledge. It is clear that the initial encouraging results described in this paper warrant further study of intravitreal bevacizumab in larger, controlled, randomized trials.

Off-label use of bevacizumab for the treatment of age-related macular degeneration: what is the evidence?

There is an active and controversial debate about the role of intravitreal bevacizumab versus approved drugs in the treatment of neovascular age-related macular degeneration (AMD). Because bevacizumab was available prior to the launch of ranibizumab, off-label use of the former became widespread and the cancer drug bevacizumab is the most commonly used medication in ophthalmology nowadays. This review considers every publication identified in MEDLINE using the keywords 'bevacizumab' and 'Avastin' between 1 June 2005 and 31 July 2008. The search identified 511 papers that were evaluated. In 33 studies, there was consistent and clear evidence for the efficacy of bevacizumab in neovascular AMD. However, the highest grade studies (three prospective, randomized, controlled trials) did not attain better than grade 2b level of evidence, and objective evaluation of the benefit of bevacizumab relative to representative controls was therefore not possible. Certainly, the available evidence is inferior to that obtained from the approval studies of ranibizumab and this should influence treatment selection and guidance of patients. These considerations indicate that important quality criteria need to be included in future studies to ensure more meaningful conclusions can be drawn. These include clearly defined inclusion criteria, information about the recruitment procedure (including data on withdrawals, excluded patients, concealed treatment allocation, use of intention-to-treat analyses and blinded assessment procedures). Although preclinical studies have almost exclusively found bevacizumab to be safe, the design utilized in clinical case series cannot rule out a possible increase in adverse events, which already show a high spontaneous incidence in elderly AMD patients. The superior evidence level for ranibizumab and the limited safety data for bevacizumab must be taken into consideration when evaluating the costs that a healthcare system is willing to spend. However, the superior grade of evidence for ranibizumab should not be confused with the (still missing) evidence for superior efficacy. The results of ongoing randomized, controlled, comparative trials will provide further data on the efficacy and cost effectiveness of bevacizumab and ranibizumab in the treatment of AMD. In the meantime, patients should be informed about the alternatives, the price differences and the restricted liability issue when off-label use of bevacizumab is offered.

Antivascular endothelial growth factor therapy for neovascular age-related macular degeneration

PURPOSE OF REVIEW

The most important recent advance in the treatment of neovascular age-related macular degeneration (AMD) is the development of antivascular endothelial growth factor (anti-VEGF) therapeutic agents that preserve and improve visual acuity by arresting choroidal neovascular growth and reducing vascular permeability. This review describes the current literature on the use of this therapeutic approach in the management of neovascular AMD.

RECENT FINDINGS

Two anti-VEGF agents, pegaptanib sodium and ranibizumab, are currently approved by the United States Food and Drug Administration for the treatment of neovascular AMD. In addition, off-label use of a third anti-VEGF agent, bevacizumab, as a treatment option for neovascular AMD has become common worldwide. Other anti-VEGF agent strategies that have shown efficacy include small interfering RNA agents to silence the VEGF gene and receptor and the fusion protein VEGF trap.

SUMMARY

The accumulation of preclinical and clinical evidence implicating VEGF-A in the pathogenesis of neovascular AMD has provided a strong rationale for the development of anti-VEGF agents for this disease. Anti-VEGF therapies have been used successfully in the clinic, encouraging their use in the treatment of other neovascular eye diseases.

The treatment of wet age-related macular degeneration

BACKGROUND

Age-related macular degeneration (AMD) is a progressive disease affecting the macula, the area of the retina that has the highest visual acuity. It can progress to geographic atrophy or choroidal neovascularization.

METHOD

Selective literature review.

RESULTS

The authors discuss the results of therapeutic trials and the treatment recommendations of the ophthalmological societies. Mechanism-targeted treatments and improved modes of administration offer the potential for improved therapy.

CONCLUSIONS

With the advent of the antivascular endothelial growth factor (anti-VEGF) therapy, the prognosis of choroidal neovascularization has changed dramatically. Visual acuity can actually be improved, but, in most cases, the improvement can only be sustained with repeated intravitreal injections.

Verteporfin combination regimens in the treatment of neovascular age-related macular degeneration

BACKGROUND

Neovascular age-related macular degeneration is characterized by choroidal neovascularization that has a complex pathogenesis. Combining agents that have different mechanisms of action (i.e., verteporfin photodynamic therapy, antivascular endothelial growth factor, and/or anti-inflammatory therapies) could maximize clinical benefits through potential complementary effects. This review discusses findings from studies investigating this hypothesis.

METHODS

Articles were retrieved from PubMed using relevant search terms. Abstracts from recent scientific meetings and details of ongoing trials from clinicaltrials.gov were also included.

RESULTS

Following its approval, verteporfin was important in the management of choroidal neovascularization due to age-related macular degeneration for several years. Improved visual outcomes have now been reported with antiangiogenic agents (e.g., intravitreal ranibizumab), especially when frequently administered. Results from investigator-sponsored trials, retrospective case studies and Registries, which have provided insights into the latest findings from clinical practice in the "real-world" setting, as well as randomized controlled trials, suggest that a combination approach is generally well tolerated and may maintain improvements in visual and anatomic outcomes with fewer retreatments.

CONCLUSION

A rationale exists for investigating combination approaches to target different processes in choroidal neovascularization pathogenesis, which may optimize treatment benefits in neovascular age-related macular degeneration. Encouraging data suggest that combination strategies are not associated with major adverse events.

Current status of anti-vascular endothelial growth factor therapy in Europe

Vascular endothelial growth factor (VEGF) is an important modulator of angiogenesis, and has been implicated in the pathology of a number of conditions, including age-related macular degeneration (AMD), diabetic retinopathy, and cancer. AMD is a progressive disease of the macula and the third major cause of blindness worldwide. If not treated appropriately, AMD can progress rapidly, causing legal blindness within months of the second eye becoming affected. Until recently, the treatment options for AMD have been limited, with photodynamic therapy (PDT) the mainstay treatment. Although PDT is effective at slowing disease progression, it rarely results in improved vision. Pegaptanib and ranibizumab are both anti-VEGF therapies licensed for the treatment of neovascular AMD in Europe; however, these drugs are not yet available in Japan. This article reviews the available clinical data on anti-VEGF therapies for the treatment of neovascular AMD in Europe, and considers the future of this exciting therapy.

Applying the CONSORT and STROBE statements to evaluate the reporting quality of neovascular age-related macular degeneration studies

PURPOSE

To evaluate the quality of reporting in the neovascular age-related macular degeneration (nvAMD) literature by applying the Consolidated Standards for Reporting Trials (CONSORT) and Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement writing standards.

DESIGN

CONSORT and STROBE impact analysis; literature review.

PARTICIPANTS

Phase III randomized controlled trials (RCTs) of verteporfin photodynamic therapy, pegaptanib, and ranibizumab, and interventional case studies of bevacizumab for nvAMD.

METHODS

A literature search identified eligible articles published before October 31, 2007. We assessed the report quality of Phase III RCTs using the CONSORT statement and case series publications using the STROBE statement, both with indicators relevant to nvAMD.

MAIN OUTCOME MEASURES

Presence or absence of CONSORT or STROBE statement indicators.

RESULTS

Seven publications of Phase III RCTs and 29 publications on bevacizumab interventional case studies for nvAMD met our inclusion criteria. Of 37 possible CONSORT writing guideline items, the mean report quality for RCTs was 30.6 (83%), with a range from 23 to 35 (65%-95%). Of 35 possible STROBE writing guideline items, the mean report quality grade for intravitreal bevacizumab case series was 23 (70%), with a range from 16 to 31 (46%-94%). Among the bevacizumab studies, more than 90% reported scientific background, drug dose and administration, baseline characteristics, unadjusted results, and adverse events. Fewer than 20% reported study size calculations, handling of missing data, or a discussion of bias.

CONCLUSIONS

Since the adoption of the CONSORT standards by Ophthalmology and other journals in 1996, the reporting quality for RCTs has further improved among this cohort of nvAMD articles. On the other hand, no reporting standards for case series have existed until the recent publication of the STROBE statement. In this first application of the STROBE standards to ophthalmology, we found that the small interventional studies in our series had an average reporting score lower than the RCTs, but also that some individual scores were higher than the RCTs. This outcome demonstrates that good, useful articles can be written about small studies. Although not a direct measure of the quality of a study, good reporting allows a reader to assess the validity and applicability of the study's findings.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Relationships between clinical measures of visual function and anatomic changes associated with bevacizumab treatment for choroidal neovascularization in age-related macular degeneration

PURPOSE

This pilot study was undertaken to examine the relationships between clinical measures of visual function and anatomic changes occurring in the eyes treated with bevacizumab for choroidal neovascularization (CNV) due to age-related macular degeneration (AMD).

METHODS

A retrospective review was conducted for 50 eyes that had been treated with at least three injections of bevicizumab for CNV due to AMD, and followed for at least 6 months. Vision outcomes included best-corrected ETDRS chart acuity, scored by best-line read (ETDRS line) and by total letters read (ETDRS letter), and two measures obtained from central acuity perimetry with 98% Michelson contrast targets, the best acuity within 6 degrees of fixation (BA6 degrees ), and global macular acuity (GMA), representing a weighted average of the acuities thresholded at all intercepts within a 10 degrees radius of fixation. Assessment of anatomic outcomes included fibrosis, atrophy, and subretinal hemorrhage grading on fundus photography, CNV size, pigment epithelial detachment (PED) size and grading of CNV leakage on fluorescein angiography, and central retinal PED, and subretinal fluid (SRF) thickness on optical coherence tomography.

RESULTS

Logistic regression analysis showed an association between the vision outcomes of EDTRS letter and BA6 degrees with the change in SRF thickness (R (2): 0.47 and 0.35, respectively). The outcome of the vision measurement of GMA was associated with the change in SRF thickness, in CNV thickness, and in CNV fibrosis grade (R (2): 0.34). No association was noted between the outcomes of ETDRS line with the change in any anatomic outcomes.

CONCLUSION

Acuity perimetry outcomes in this study seemed to offer improved understanding of the relationship between the vision outcomes and the measured anatomic changes. It seemed that neither ocular coherence tomography nor fluorescein angiography alone offered sufficient morphologic markers for prediction of functional outcomes.

Anti-vascular endothelial growth factor pharmacotherapy for age-related macular degeneration: a report by the American Academy of Ophthalmology

OBJECTIVE

To examine the evidence about the safety and efficacy of anti-vascular endothelial growth factor (VEGF) pharmacotherapies for the treatment of neovascular age-related macular degeneration (AMD).

DESIGN

Literature searches were conducted in May and October 2007 in PubMed with no date restrictions, limited to articles published in English, and in the Cochrane Central Register of Controlled Trials without a language limitation and yielded 310 citations. The first author reviewed the abstracts of these articles and selected 73 articles of possible clinical relevance for review by the panel. The panel deemed 64 of these articles sufficiently clinically relevant to review in full text and assigned ratings of level of evidence to each of the selected articles with the guidance of the panel methodologists.

RESULTS

Eleven studies provided level I evidence for intravitreal pegaptanib and ranibizumab for neovascular AMD; there were no studies rated level I for bevacizumab for neovascular AMD. Five studies were rated as level II, which included studies of ranibizumab and bevacizumab, and the remaining 38 articles retrieved were rated as level III. The studies do not provide information about long-term results or the value (comparative effectiveness) and cost-effectiveness of combined therapies.

CONCLUSIONS

Review of the available literature to date suggests that anti-VEGF pharmacotherapy, delivered by intravitreal injection, is a safe and effective treatment for neovascular AMD for up to 2 years. There is level I evidence to support this conclusion for pegaptanib and ranibizumab, but none for bevacizumab at this time.

Vitreous levels of bevacizumab and vascular endothelial growth factor-A in patients with choroidal neovascularization

PURPOSE

To investigate the vitreous levels of bevacizumab and vascular endothelial growth factor-A (VEGF-A) after intravitreal injection of the drug in patients with choroidal neovascularization (CNV).

DESIGN

Interventional case series.

PARTICIPANTS

Eleven eyes of 11 patients with submacular hemorrhage and CNV due to age-related macular degeneration (n = 10) or angioid streaks (n = 1).

METHODS

All patients were treatment naïve except for a single dose of intravitreal injection of bevacizumab (1.25 mg/50 muL dose) and subsequent vitrectomy after various intervals (1-101 days) because of active and progressive lesion. Intravitreal free bevacizumab and VEGF-A levels were measured using enzyme-linked immunosorbent assay and microsphere-based immunoassay, respectively. Vitreous VEGF-A isoforms were analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis and Western blotting.

MAIN OUTCOME MEASURES

Intravitreal bevacizumab and VEGF-A levels were measured and pharmacokinetic parameters were calculated.

RESULTS

Pharmacokinetics of intravitreal bevacizumab followed a 2-compartment model with initial and terminal half-lives of 0.5 and 6.7 days, respectively. Bevacizumab could be detected in all cases, ranging from 2.63 ng/ml to 165 microg/ml. The peak concentration was observed on the second day after intravitreal bevacizumab injection. Vitreous free VEGF-A levels ranged from 0.2 to 33.9 pg/ml and showed a negative correlation with the bevacizumab concentration (P<0.001; r = -0.955) and a positive correlation with time (P<0.001; r = 0.964). However, the percentage expression of VEGF-A(165) exhibited a positive correlation with the bevacizumab concentration (P = 0.032, r = 0.645) and a negative correlation with time (P = 0.007, r = -0.755). A time-dependent increase was found for the percentage expression of VEGF-A(189) (P = 0.023, r = 0.673). Neither bevacizumab- nor time-related alterations were found for VEGF-A(121).

CONCLUSIONS

Based on pharmacokinetics, the interval of 6-7 weeks would be appropriate for efficacy, although clinical trials should guide dosing recommendations. Vitreous levels of free VEGF-A showed a negative correlation with the bevacizumab concentration, which confirmed the in vivo binding affinity of bevacizumab to VEGF-A. The analysis of the VEGF-A isoforms suggests differences of interaction between bevacizumab and individual VEGF-A isoforms.