Comparison of Ranibizumab With or Without Verteporfin Photodynamic Therapy for Polypoidal Choroidal Vasculopathy: The EVEREST II Randomized Clinical Trial

Question

What are the differences in treatment outcomes of combination therapy with intravitreal ranibizumab and verteporfin photodynamic therapy vs ranibizumab monotherapy in polypoidal choroidal vasculopathy at month 24?

Findings

In the EVEREST II randomized clinical trial, combination therapy was superior to monotherapy in terms of adjusted mean best-corrected visual acuity gain and superior in achieving complete absence of indocyanine green hyperfluorescence of polypoidal lesions with fewer ranibizumab injections.

Meaning

These data suggest that ranibizumab plus prompt verteporfin photodynamic therapy is more effective compared with ranibizumab monotherapy for polypoidal choroidal vasculopathy with reduced treatment burden.

Importance

The 2-year efficacy and safety of combination therapy of ranibizumab administered together with verteporfin photodynamic therapy (vPDT) compared with ranibizumab monotherapy in participants with polypoidal choroidal vasculopathy (PCV) are unclear.

Objective

To compare treatment outcomes of ranibizumab, 0.5 mg, plus prompt vPDT combination therapy with ranibizumab, 0.5 mg, monotherapy in participants with PCV for 24 months.

Design, Setting, and Participants

This 24-month, phase IV, double-masked, multicenter, randomized clinical trial (EVEREST II) was conducted among Asian participants from August 7, 2013, to March 2, 2017, with symptomatic macular PCV confirmed using indocyanine green angiography.

Interventions

Participants (N = 322) were randomized 1:1 to ranibizumab, 0.5 mg, plus vPDT (combination therapy group; n = 168) or ranibizumab, 0.5 mg, plus sham PDT (monotherapy group; n = 154). All participants received 3 consecutive monthly ranibizumab injections, followed by a pro re nata regimen. Participants also received vPDT (combination group) or sham PDT (monotherapy group) on day 1, followed by a pro re nata regimen based on the presence of active polypoidal lesions.

Main Outcomes and Measures

Evaluation of combination therapy vs monotherapy at 24 months in key clinical outcomes, treatment exposure, and safety. Polypoidal lesion regression was defined as the absence of indocyanine green hyperfluorescence of polypoidal lesions.

Results

Among 322 participants (mean [SD] age, 68.1 [8.8] years; 225 [69.9%] male), the adjusted mean best-corrected visual acuity (BCVA) gains at month 24 were 9.6 letters in the combination therapy group and 5.5 letters in the monotherapy group (mean difference, 4.1 letters; 95% CI, 1.0–7.2 letters; P = .005), demonstrating that combination therapy was superior to monotherapy by the BCVA change from baseline to month 24. Combination therapy was superior to monotherapy in terms of complete polypoidal lesion regression at month 24 (81 of 143 [56.6%] vs 23 of 86 [26.7%] participants; P < .001). Participants in the combination group received fewer ranibizumab injections (median, 6.0 [interquartile range (IQR), 4.0-11.0]) than the monotherapy group (median, 12.0 [IQR, 7.0-17.0]) up to month 24. The combination group required a median of 2.0 (IQR, 1.0-3.0) vPDT treatments for 24 months, with 75 of 168 participants (44.6%) requiring only 1 vPDT treatment.

Conclusions and Relevance

The 24-month data findings confirm that ranibizumab therapy, given as monotherapy or in combination with vPDT, is efficacious and safe for treatment of PCV. Combination therapy with vPDT added to ranibizumab achieved superior BCVA gain, increased odds of complete polypoidal lesion regression, and fewer treatment episodes compared with ranibizumab monotherapy.

Trial Registration

ClinicalTrials.gov Identifier: NCT01846273.

RANIBIZUMAB WITH OR WITHOUT VERTEPORFIN PHOTODYNAMIC THERAPY FOR POLYPOIDAL CHOROIDAL VASCULOPATHY: Predictors of Visual and Anatomical Response in the EVEREST II Study

PURPOSE

To evaluate the demographic and imaging factors at baseline and Month 3 (M3) that predict visual or anatomical responses at Month 12 (M12) in the EVEREST-II study for polypoidal choroidal vasculopathy.

METHODS

Post-hoc analysis of 322 participants in the EVEREST-II study. Patient factors, best-corrected visual acuity (BCVA), treatment, and imaging parameters at baseline and M3 were evaluated with respect to outcomes at M12 using univariate and multivariable analysis.

RESULTS

Younger age (P < 0.001) and lower baseline BCVA (P < 0.001) were associated with higher BCVA gains at M12. Smaller baseline polypoidal lesion area was associated with higher BCVA gains at M12 only in the ranibizumab monotherapy arm (P = 0.008). Central subfield thickness at M3, area of branching vascular network at M3, BCVA at M3, and age were associated with change in BCVA from M3 at M12. Higher odds of fluid-free retina at M12 were associated with lower baseline central subfield thickness (P = 0.006), treatment with combination therapy (baseline and M3 models; P < 0.001), and absence of subretinal fluid at M3 (P < 0.001).

CONCLUSION

Several imaging parameters at baseline and M3 can predict treatment outcome. The interaction between treatment arm and total polypoidal lesion area suggests this feature may assist selecting between initial ranibizumab monotherapy or combination therapy.

Functional versus functional and anatomical criteria-guided ranibizumab treatment in patients with neovascular age-related macular degeneration - results from the randomized, phase IIIb OCTAVE study

Background

To evaluate the efficacy and safety of two individualized ranibizumab retreatment schemes in neovascular age-related macular degeneration.

Methods

Patients (N = 671) were randomized (1:1) to receive three initial monthly ranibizumab 0.5 mg injections, then retreatment guided by either best-corrected visual acuity (BCVA) loss (Group I) or BCVA loss and/or signs of disease activity on optical coherence tomography (OCT; Group II). The study was terminated prematurely and the decision to discontinue the study was made by the sponsor. Efficacy analyses were performed on patients who completed 12 months of the originally planned 24-month study. Safety analyses are presented for all safety analyzable patients.

Results

Of 671 randomized patients, 305 completed 12 months of the study. For the 12-month completers, baseline mean (standard deviation) BCVA and reading-center evaluated central subfield thickness (CSFT) were comparable [Group I: 60.9 (13.10) letters and 517.7(201.79) μm; Group II: 60.2 (12.21) letters and 515.3 (198.37) μm]. The change from baseline at Month 12 in BCVA was 6.7 (13.48) letters in Group I and 8.3 (13.53) letters in Group II and the change in CSFT was − 161.3 (163.48) μm and − 175.3 (170.45) μm, respectively. The mean number of ranibizumab injections was 8.2 in Group I and 8.4 in Group II.

Conclusion

Ranibizumab treatment resulted in visual and anatomic gains at 12 months for both retreatment strategies, with a trend in favor of OCT-guided vs BCVA loss guided retreatment. No new safety signals were seen.

Trial registration

www.ClinicalTrials.gov (NCT01780935). Registered 31 January 2013.

Visual benefit versus visual gain: what is the effect of baseline covariants in the treatment arm relative to the control arm? A pooled analysis of ANCHOR and MARINA

Background

This study aimed to elucidate visual benefits of ranibizumab in patients with neovascular age-related macular degeneration (nAMD) compared with control arms and identify factors affecting response.

Methods

This is a post-hoc pooled analysis of two phase III studies, ANCHOR and MARINA, of ranibizumab for the treatment of nAMD. ANCHOR included 83 international sites. MARINA included 96 sites in the USA. Analysis included patients (control, n=323; ranibizumab, n=332) with nAMD and a baseline best-corrected visual acuity (BCVA) of ≥35–<85 letters.

Results

Patients receiving ranibizumab achieved an adjusted mean BCVA superiority of 18.9 and 21.2 letters over 12 and 24 months, respectively, compared with control. Ranibizumab treatment, higher baseline BCVA, lower age and smaller lesion size were positively associated with the ability to achieve BCVA >69 letters. Patients with the highest baseline BCVA had lowest BCVA gains. Ranibizumab treatment, lower baseline BCVA, lower age and smaller lesion size were identified as significant predictors of BCVA gain from baseline at month 24 (all p<0.0001). However, the difference in mean BCVA gains at month 24 between treatment and control groups was similar for all baseline BCVA subgroups (≥35–<55 letters, 21.9 letters; ≥55–<70 letters, 25.2 letters; ≥70–<85 letters, 19.3 letters).

Conclusions

Higher baseline BCVA is associated with lower BCVA gains but a greater likelihood of achieving good final BCVA >69 letters due to smaller gains needed to achieve response. Visual benefits, including maintenance of visual acuity (VA), final VA achieved and relative gain compared with natural disease progression, should be considered when assessing treatment response in nAMD.

Dose-response analysis of ranibizumab as-needed regimens for visual improvement in patients with diabetic macular edema using a modelling approach

BACKGROUND

Ranibizumab and aflibercept are anti-vascular endothelial growth factor therapies for diabetic macular edema (DME) but have only been directly compared in one study: the Protocol T study, a 24-month randomized controlled trial which compared the safety and efficacy of three anti-VEGF agents (ranibizumab 0.3 mg, aflibercept 2.0 mg and bevacizumab 1.25 mg). The ranibizumab dose used in Protocol T is not licensed for use outside of the US, where a higher ranibizumab dose of 0.5 mg is approved. Therefore, the relevance of the head-to-head Protocol T study findings to healthcare providers in Europe is limited. The purpose of this research was to predict the visual outcomes that may have been achieved in Protocol T with ranibizumab 0.5 mg.

METHODS

A simplified dose-response model was constructed to describe the relationship between average monthly dose and one-year best corrected visual acuity (BCVA) change from baseline. A linear mixed effects model was evaluated and Bayesian Monte-Carlo Markov chains method was used to estimate the model parameters.

RESULTS

If ranibizumab 0.5 mg PRN had been studied in Protocol T, it would have resulted in a BCVA gain of 14-15 early treatment diabetic retinopathy study (ETDRS) letters; 3-4 letters more than the actual BCVA gain reported with ranibizumab 0.3 mg PRN. In Protocol T patients with poor baseline BCVA (<69 letters), a similar additional letter gain would have been achieved.

CONCLUSION

The relevance of the Protocol T study findings are limited due to the use of ranibizumab 0.3 mg PRN which, based on the modelling approach reported herein, resulted in sub-optimal visual gains.

Efficacy and safety of ranibizumab monotherapy versus ranibizumab in combination with verteporfin photodynamic therapy in patients with polypoidal choroidal vasculopathy: 12-month outcomes in the Japanese cohort of EVEREST II study

Purpose

To compare the efficacy and safety of ranibizumab 0.5 mg with or without verteporfin photodynamic therapy in Japanese patients with polypoidal choroidal vasculopathy over 12 months.

Study design

EVEREST II was a 24-month, Phase IV, multicenter, randomized, double-masked study in Asian patients with symptomatic macular polypoidal choroidal vasculopathy.

Methods

Of the 322 enrolled patients, 84 patients, including 46 patients who received ranibizumab + verteporfin photodynamic therapy (combination therapy arm) and 38 patients who received ranibizumab/sham PDT (monotherapy arm), were Japanese who were evaluated in this subanalysis. Mean change in best-corrected visual acuity (BCVA) and complete polyp regression at Month 12, ranibizumab treatment exposure, and safety over 12 months were assessed.

Results

Baseline demographics were well balanced between the arms. At Month 12, mean change in BCVA letter score was +8.5 with combination therapy versus +6.4 with monotherapy. Complete polyp regression was higher with combination therapy than with monotherapy at Month 12 (70.5% vs 27.3%). Over 12 months, patients in the combination arm received a median of 4.0 ranibizumab injections vs 7.0 in the monotherapy arm. Serious adverse events were generally low in both arms, and retinal hemorrhage, an adverse event, was reported in one patient (2.2%).

Conclusion

The results from the Japanese cohort were in agreement with the EVEREST II study. Combination therapy was effective in improving BCVA and achieving a higher rate of complete polyp regression with a lower number of ranibizumab injections than monotherapy. No new safety signals were reported, and safety events were comparable between both arms over 12 months.

MACUSTAR: Development and Clinical Validation of Functional, Structural, and Patient-Reported Endpoints in Intermediate Age-Related Macular Degeneration

PURPOSE

Currently, no outcome measures are clinically validated and accepted as clinical endpoints by regulatory agencies for drug development in intermediate age-related macular degeneration (iAMD). The MACUSTAR Consortium, a public-private research group funded by the European Innovative Medicines Initiative intends to close this gap.

PROCEDURES

Development of study protocol and statistical analysis plan including predictive modelling of multimodal endpoints based on a review of the literature and expert consensus.

RESULTS

This observational study consists of a cross-sectional and a longitudinal part. Functional outcome measures assessed under low contrast and low luminance have the potential to detect progression of visual deficit within iAMD and to late AMD. Structural outcome measures will be multimodal and investigate topographical relationships with function. Current patient-reported outcome measures (PROMs) are not acceptable to regulators and may not capture the functional deficit specific to iAMD with needed precision, justifying development of novel PROMs for iAMD. The total sample size will be n = 750, consisting mainly of subjects with iAMD (n = 600).

CONCLUSIONS

As clinical endpoints currently accepted by regulators cannot detect functional loss or patient-relevant impact in iAMD, we will clinically validate novel candidate endpoints for iAMD.

Systemic Safety in Ranibizumab-Treated Patients with Neovascular Age-Related Macular Degeneration: A Patient-Level Pooled Analysis

TOPIC

This study evaluated the cardiovascular/cerebrovascular safety profile of ranibizumab 0.5 mg versus sham ± verteporfin in patients with neovascular age-related macular degeneration (nAMD). In addition, comparisons of ranibizumab 0.3 mg with sham and ranibizumab 0.5 mg to 0.3 mg were performed.

CLINICAL RELEVANCE

Intravitreal anti-vascular endothelial growth factor (VEGF) agents carry potential increased systemic risks, including cardiovascular or cerebrovascular events. Pooled safety analyses allow better interpretation of safety outcomes seen in individual clinical trials, especially for less common events. To our knowledge, this is the largest patient-level pooled analysis of patients with nAMD treated with ranibizumab.

METHODS

Patient-level pooled analysis of data from 7 Genentech- and Novartis-sponsored phase II, III, and IV studies in nAMD that were completed by December 31, 2013. Pairwise comparisons (primary comparison: ranibizumab 0.5 mg [globally approved dose for nAMD] vs. sham or verteporfin) were performed using Cox proportional hazard regression (hazard ratios [HRs], 95% confidence intervals [CIs]) and rates per 100 patient-years. Standardized Medical Dictionary for Regulatory Activities queries (SMQs) and extended searches were used to identify relevant safety endpoints, including arterial thromboembolic events (ATEs), myocardial infarction (MI), stroke or transient ischemic attack (TIA), stroke (excluding TIA), vascular deaths, and major vascular events as defined by the Antiplatelet Trialists' Collaboration (APTC).

RESULTS

The HRs (95% CIs) for the primary comparison of ranibizumab 0.5 mg (n=480) versus sham or verteporfin (n=462) were 1.16 (0.72-1.88) for ATE, 1.33 (0.59-2.97) for MI, 1.43 (0.54-3.77) for stroke excluding TIA, 1.25 (0.61-2.55) for stroke or TIA, 0.57 (0.18-1.78) for vascular death, and 1.12 (0.64-1.98) for APTC events. Hazard ratio 95% CIs included 1, indicating no significant treatment differences, for all endpoints for comparison of ranibizumab 0.5 mg versus sham or verteporfin.

CONCLUSIONS

The rates of cardiovascular and cerebrovascular events were low in these patients with nAMD and not clinically meaningfully different for patients treated with ranibizumab 0.5 mg versus sham or verteporfin, which supports the favorable benefit-risk profile of ranibizumab in the patient population with nAMD. Pooling these studies allows an analysis with higher power and precision compared with individual study analyses.

Efficacy and Safety of Ranibizumab With or Without Verteporfin Photodynamic Therapy for Polypoidal Choroidal Vasculopathy: A Randomized Clinical Trial

Importance

Polypoidal choroidal vasculopathy (PCV) is a common subtype of exudative age-related macular degeneration among Asian individuals. To our knowledge, there are no large randomized clinical trials to evaluate intravitreal ranibizumab, with and without verteporfin photodynamic therapy (vPDT), for the treatment of PCV.

Objective

To compare the efficacy and safety of combination therapy of ranibizumab and vPDT with ranibizumab monotherapy in PCV.

Design, Setting, and Participants

A double-masked, multicenter randomized clinical trial of 322 Asian participants with symptomatic macular PCV confirmed by the Central Reading Center using indocyanine green angiography was conducted between August 7, 2013, and March 2, 2017.

Interventions

Participants were randomized 1:1 to ranibizumab, 0.5 mg, and vPDT (n = 168; combination therapy group) or ranibizumab, 0.5 mg, and sham PDT (n = 154; monotherapy group). All participants received 3 consecutive monthly ranibizumab injections, followed by a pro re nata regimen. Participants also received vPDT/sham PDT on day 1, followed by a pro re nata regimen based on the presence of active polypoidal lesions.

Main Outcomes and Measures

Step 1 assessed whether combination therapy was noninferior (5-letter margin) to monotherapy for change in best-corrected visual acuity from baseline and superior in complete polyp regression. If noninferiority was established, step 2 assessed whether combination therapy was superior to monotherapy measured by best-corrected visual acuity change at month 12.

Results

Baseline demographics of the 322 participants were comparable between the treatment groups. Mean (SD) age of the patients was 68.1 (8.8) years, and overall, 69.9% of the patients were men. At baseline, the overall mean best-corrected visual acuity and mean central subfield thickness were 61.1 letters and 413.3 μm, respectively. At 12 months, mean improvement from baseline was 8.3 letters with combination therapy vs 5.1 letters with monotherapy (mean difference, 3.2 letters; 95% CI, 0.4-6.1), indicating that combination therapy met the predefined criterion for noninferiority as well as being superior to monotherapy (P = .01). Combination therapy was also superior to monotherapy in achieving complete polyp regression at month 12 (69.3% vs 34.7%; P < .001). Over 12 months, the combination therapy group received a median of 4.0 ranibizumab injections compared with 7.0 in the monotherapy group. Vitreous hemorrhage was the only ocular serious adverse event (combination therapy group, 1 [0.6%]; monotherapy group, 3 [2.0%]).

Conclusions and Relevance

After 12 months, combination therapy of ranibizumab plus vPDT was not only noninferior but also superior to ranibizumab monotherapy in best-corrected visual acuity and superior in complete polyp regression while requiring fewer injections. Combination therapy should be considered for eyes with PCV.

Trial Registration

clinicaltrials.gov Identifier: NCT01846273.

Ranibizumab in Diabetic Macular Oedema - A Benefit-risk Analysis of Ranibizumab 0.5 mg PRN Versus Laser Treatment

INTRODUCTION

The structured Benefit-risk Action Team (BRAT) approach aims to assist healthcare decision makers in treatment assessments. We applied BRAT to compare the benefit-risk profile of ranibizumab 0.5 mg versus laser photocoagulation for the treatment of diabetic macular oedema (DMO).

METHODS

One-year data for the ranibizumab 0.5 mg pro re nata (PRN) and laser arms of the phase III trials RESPOND (NCT01135914; n=220), RESTORE (NCT00687804; n=345), and REVEAL (NCT00989989; n=396) were included in the analysis. The benefit measures included ≥10 letters gain/avoidance of loss in best-corrected visual acuity (BCVA), achieving central retinal thickness (CRT) <275 μm, and 25-item Visual Function Questionnaire (VFQ-25) outcomes. The risks measures included endophthalmitis, intraocular pressure increase, hypertension, proteinuria, arterial/venous thromboembolic events and deaths.

RESULTS

Ranibizumab treatment provided significant benefits compared with laser for ≥10 letter BCVA gain at month 12 (387/1,000 versus 152/1,000 patients), CRT <275 μm at 12 months (474/1,000 versus 348/1,000 patients), and improvement of ≥6.06 on the VFQ-25 near activities subscale (325/1,000 versus 245/1,000 patients). Results for the risk measures were similar for both treatments.

CONCLUSIONS

Superior clinically relevant outcomes were observed with ranibizumab 0.5 mg PRN compared with laser without compromising on safety. This analysis further supports the positive benefit-risk profile of ranibizumab 0.5 mg PRN.

Vascular Safety of Ranibizumab in Patients With Diabetic Macular Edema: A Pooled Analysis of Patient-Level Data From Randomized Clinical Trials

Importance

Patients with diabetic macular edema (DME) are at high risk of vascular complications, including stroke and myocardial infarction (MI). Concerns have been raised that intravitreal dosing of vascular endothelial growth factor inhibitors in DME could be associated with an increase in cardiovascular and cerebrovascular adverse events.

Objective

To evaluate the cardiovascular and cerebrovascular safety of ranibizumab, 0.5 mg and 0.3 mg, compared with sham with and without laser in DME.

Data Sources

Patient-level data from 6 randomized, double-masked, sham- and laser-controlled clinical trials.

Study Selection

Company-sponsored (Genentech or Novartis) studies in DME completed as of December 31, 2013.

Data Extraction and Synthesis

Pairwise comparisons (ranibizumab, 0.5 mg, vs sham and laser; ranibizumab, 0.3 mg, vs sham) were performed using Cox proportional hazard regression (hazard ratios, 95% CIs) and rates per 100 person-years. Data analysis was conducted from June 1 to July 15, 2015.

Main Outcomes and Measures

Standardized Medical Dictionary for Regulatory Activities queries and extended searches were prospectively defined to identify relevant safety end points, including arterial thromboembolic events, MI, stroke or transient ischemic attack, vascular deaths, and major vascular events as defined by the Antiplatelet Trialists' Collaboration (APTC).

Results

Overall, 936 patients were treated with ranibizumab, 0.5 mg; 250 patients with ranibizumab, 0.3 mg; and 581 patients with sham/laser. The hazard ratios associated with all pairwise comparisons included 1 for all key cardiovascular and cerebrovascular safety end points. For ranibizumab, 0.5 mg, vs sham/laser and ranibizumab, 0.3 mg, vs sham, the hazard ratios were, respectively, arterial thromboembolic events, 1.05 (95% CI, 0.66-1.68) and 0.78 (95% CI, 0.43-1.40); MI, 0.84 (95% CI, 0.41-1.72) and 0.94 (95% CI, 0.43-2.06); stroke or transient ischemic attack, 0.94 (95% CI, 0.44-1.99) and 0.53 (95% CI, 0.19-1.42); stroke (excluding transient ischemic attack), 1.63 (95% CI, 0.65-4.07) and 0.59 (95% CI, 0.14-2.46); vascular death, 2.17 (95% CI, 0.57-8.29) and 2.51 (95% CI, 0.49-12.94); and APTC-defined events, 1.09 (95% CI, 0.63-1.88) and 1.00 (95% CI, 0.51-1.96).

Conclusions and Relevance

This pooled analysis includes 1 of the largest patient-level data sets on treatment of DME with ranibizumab. Although still underpowered to detect small differences for infrequent events, such as stroke, the findings suggest that intravitreous ranibizumab does not increase the risk of systemic vascular events. However, uncertainty remains for patients with DME who are at high risk for vascular disease and were not included in these trials.

Baseline visual acuity strongly predicts visual acuity gain in patients with diabetic macular edema following anti-vascular endothelial growth factor treatment across trials

Objective

This study was designed to evaluate the correlation of baseline visual acuity (VA) with VA outcome in response to anti-vascular endothelial growth factor (VEGF) in diabetic macular edema using a retrospective analysis of nine clinical trials. The result will help assess the relevance of VA gain comparisons across trials.

Methods

A correlation analysis was performed between mean baseline VA and VA gain at month 12 for 1,616 diabetic macular edema patients across nine randomized clinical trials (RESOLVE, RISE, RIDE, RESTORE, RETAIN, DRCR.net Protocol I, DA VINCI, VIVID, VISTA) with anti-VEGF treatment regimens ranibizumab 0.5 mg and aflibercept 2 mg.

Results

The mean baseline VA ranged from 56.9 to 64.8 Early Treatment Diabetic Retinopathy Study (ETDRS) letters. The mean VA gain at month 12 ranged from 6.8 to 13.1 ETDRS letters across trials. There was a strong inverse correlation between mean baseline VA and VA gain at month 12 (r=−0.85). The mean VA at 12 months plateaued at ~70 (68.5–73.0) ETDRS letters (20/40 Snellen VA equivalent) for the anti-VEGF treatment groups from all trials, regardless of dosing regimens and agents.

Conclusion

Cross-trial comparisons based on changes in best-corrected visual acuity should be done cautiously and only after adjusting for best-corrected visual acuity at baseline. Furthermore, the total VA afforded by treatment appears to be subject to a plateau effect, which warrants further exploration.

Predictive Value of Retinal Morphology for Visual Acuity Outcomes of Different Ranibizumab Treatment Regimens for Neovascular AMD

PURPOSE

To establish the predictive value of defined retinal morphologic parameters on visual outcomes and re-treatment needs in patients with neovascular age-related macular degeneration (nAMD) receiving ranibizumab treatment.

DESIGN

Post hoc analysis of a prospective, 12-month, multicenter, phase IIIb trial.

PARTICIPANTS

Three hundred fifty-three treatment-naïve patients with nAMD.

METHODS

Available data from 319 treatment-naïve patients receiving ranibizumab 0.3 mg monthly (frequent regimen; n = 102) or ranibizumab 0.3 or 0.5 mg quarterly (pooled 0.3/0.5 mg = infrequent regimen; n = 217) were analyzed to assess the correlations between baseline retinal morphologic parameters and best-corrected visual acuity (BCVA) change (structure-function correlations). The BCVA was measured at monthly visits. Optical coherence tomography scans were acquired monthly for quantitative measures of the central retinal thickness and qualitative assessment of retinal morphologic features. Assessed morphologic parameters included intraretinal cystoid fluid (IRC), subretinal fluid (SRF), pigment epithelial detachment, and vitreomacular interface configuration classification comprising vitreomacular adhesion and posterior vitreous detachment (PVD). An analysis of covariance was conducted to evaluate the impact of retinal morphologic features on BCVA change at month 12.

MAIN OUTCOME MEASURES

Change in BCVA from baseline to month 12 compared between frequent and infrequent treatment arms.

RESULTS

Relevant predictive factors for BCVA change at month 12 were baseline SRF (P = 0.05), PVD (P = 0.03), IRC (P = 0.05), treatment frequency (P < 0.01), and BCVA (P < 0.01). The presence of both SRF and PVD at baseline was associated with similar BCVA gains regardless of treatment frequency (mean difference in BCVA gains at month 12 of +2.6 letters in favor of infrequent treatment). Subretinal fluid was present in 71% of patients, and PVD was present in 64% of patients.

CONCLUSIONS

In patients with both SRF and PVD at baseline, similar BCVA outcomes were observed regardless of treatment frequency. These patients may require less frequent treatments compared with patients without SRF, without PVD, or without either who may require more frequent injections for maintenance of vision. This finding may have implications in clinical practice by helping to tailor an individualized re-treatment interval in nAMD patients.

Apolipoprotein B100 secretion by cultured ARPE-19 cells is modulated by alteration of cholesterol levels

Cholesteryl ester rich apolipoprotein B100 (apoB100) lipoproteins accumulate in Bruch's membrane before the development of age-related macular degeneration. It is not known if these lipoproteins come from the circulation or local ocular tissue. Emerging, but incomplete evidence suggests that the retinal pigmented epithelium (RPE) can secrete lipoproteins. The purpose of this investigation was to determine (i) whether human RPE cells synthesize and secrete apoB100, and (ii) whether this secretion is driven by cellular cholesterol, and if so, (iii) whether statins inhibit this response. The established, human derived ARPE-19 cells challenged with 0-0.8 mM oleic acid accumulated cellular cholesterol, but not triglycerides. Oleic acid increased the amount of apoB100 protein recovered from the medium by both western blot analysis and (35) S-radiolabeled immunoprecipitation while negative stain electron microscopy showed lipoprotein-like particles. Of nine statins evaluated, lipophilic statins induced HMG-CoA reductase mRNA expression the most. The lipophilic Cerivastatin (5 μM) reduced cellular cholesterol by 39% and abrogated apoB100 secretion by 3-fold. In contrast, the hydrophilic statin Pravastatin had minimal effect on apoB100 secretion. These data suggest that ARPE-19 cells synthesize and secrete apoB100 lipoproteins, that this secretion is driven by cellular cholesterol, and that statins can inhibit apoB100 secretion by reducing cellular cholesterol.

Evaluation of 9-cis-retinyl acetate therapy in Rpe65-/- mice

PURPOSE

Mice lacking retinal pigment epithelium-specific 65-kDa protein (RPE65) develop retinopathy and blindness resembling Leber congenital amaurosis. Effects of 9-cis-retinyl acetate (9-cis-R-Ac) on visual function and retinopathy progression were tested in Rpe65(-/-) mice.

METHODS

Young C57Bl/6 mice were given 9-cis-R-Ac in each of four different oil-based vehicle solutions by gastric gavage to identify the vehicle most suitable for drug delivery by measuring retinoid levels in plasma. Then doses of 9-cis-R-Ac ranging from 1 to 100 mg/kg were administered to 5- to 12-week-old Rpe65(-/-) mice by different treatment regimens, including single doses and either intermittent or daily doses for various periods up to 8 weeks. Retinoid effects on visual function were evaluated by electroretinography, retinoid analyses, histologic methods, and vision-dependent behavioral testing.

RESULTS

Soybean oil vehicle provided the highest 9-cis-R-Ac metabolite levels in plasma. Single doses of 9-cis-R-Ac (6.25-50 mg/kg) provided significant dose-dependent improvement in electroretinographic responses. Well-tolerated daily doses (1-12.5 mg/kg) for 2 weeks induced remarkable improvement of retinal function. Significant dose-dependent improvement of electroretinographic responses was observed 6 days after administration of 9-cis-R-Ac daily for 3 days at 1 to 12.5 mg/kg. Mice given either daily or intermittent 9-cis-R-Ac treatment at 1 and 4 mg/kg and evaluated 8 weeks later displayed dose-dependent improvement of retinal function and morphology, whereas retinal function deteriorated in control animals. Treated mice also performed better than control animals in vision-dependent behavioral tests.

CONCLUSIONS

Treatment with 9-cis-R-Ac improves visual function and preserves retinal morphology in Rpe65(-/-) mice.

Comparing pegaptanib and triamcinolone efficacy in the rat choroidal neovascularization model

OBJECTIVE

To evaluate the prophylactic effect of intravitreal pegaptanib sodium on choroidal neovascularization membrane (CNVM) development and compare its performance with that of triamcinolone acetonide.

METHODS

In drug-treated and control groups, CNVMs were induced by laser trauma. Immediately after undergoing the laser procedure, animals received intravitreal injections of pegaptanib sodium, 8 or 17 mug; triamcinolone acetonide, 200 mug; or a vehicle solution. After 21 days, fluorescein angiography was performed. The CNVM mean diameters and radial thicknesses were measured histologically.

RESULTS

Mean CNVM diameters were 10% to 13% smaller in pegaptanib-treated eyes and 43% smaller in triamcinolone-treated eyes compared with laser-only control eyes. Late-stage fluorescein angiography leakage scores, on a scale of 0 to 3, suggested a statistical difference between triamcinolone- (0.6) and pegaptanib(8 microg)-treated (1.5) groups compared with the laser-only control group (2.0). The CNVM mean thicknesses were greater in the pegaptanib(8 microg)- (79 microm) and pegaptanib(17 microg)-treated (71 microm) groups and significantly smaller in the triamcinolone-treated group (26 microm) compared with the laser-only control group (67 microm).

CONCLUSION

In this animal model of choroidal neovascularization, intravitreal pegaptanib exhibited marginal or no effect on CNVM development; whereas intravitreal triamcinolone evoked robust inhibition of CNVMs. Clinical Relevance Pegaptanib treatment may be insufficient to prevent CNVM formation.

Photodynamic therapy with verteporfin in a rabbit model of corneal neovascularization

PURPOSE

To determine the efficacy of photodynamic therapy (PDT) with verteporfin (Visudyne; Novartis AG, Basel, Switzerland) for treatment of corneal neovascularization in a rabbit eye model.

METHODS

Corneal neovascularization was induced in Dutch belted rabbits by placing an intrastromal silk suture near the limbus. Verteporfin was administered by intravenous injection at a dose of 1.5 mg/kg, and the pharmacokinetics of verteporfin distribution in the anterior segment or PDT-induced (laser energy levels 17, 50, and 150 J/cm(2)) regression of corneal blood vessels were then determined. To assess PDT-induced toxicity of the anterior segment, corneal and iris/ciliary body histology, and IOP were evaluated after PDT.

RESULTS

Verteporfin accumulation in vascularized regions of the cornea and the iris/ciliary body tissue were time dependent and maximum levels achieved at 60 minutes after injection. In rabbits, PDT of corneal vessels using laser energy of 17 or 50 J/cm(2) resulted in 30% to 50% regression of corneal neovascularization; however, in these animals, a rapid regrowth of new blood vessels occurred between 3 and 5 days. In the rabbits receiving PDT using laser energies of 150 J/cm(2), the mean vessel regression was 56%. During the nine days of the laser therapy follow-up period, no vessel regrowth was observed in these rabbits. Histologic examination of the anterior segment after PDT (150 J/cm(2)) showed localized degeneration of the corneal blood vessels without observable change in other anterior segment structures.

CONCLUSIONS

These results provide evidence that PDT can produce significant regression of neovascular corneal vessels with no observable toxicity to the anterior segments. However, the optimal laser energy necessary to induce long-term regression (150 J/cm(2)) was three times that used to treat choroidal neovascularization.

Rapid induction of apoptosis in human keratinocytes with the photosensitizer QLT0074 via a direct mitochondrial action

QLT0074 is a newly introduced, porphyrin-derivative for use in photodynamic therapy (PDT). In the current study, the intracellular distribution of QLT0074 and the mode of cell death induced by photosensitization with this compound in vitro were assessed for transformed human HaCaT keratinocytes. Fluorescence microscopy studies indicated a distribution of the drug to the cytoplasm, nuclear membrane and mitochondria of these cells. In the absence of light, QLT0074 produced no evidence of apoptosis-related biochemical changes or affected cell viability. When combined with blue light exposure, cytotoxicity was exerted in a QLT0074- and light-dose-related manner. Appearance of the mitochondrial protein cytochrome c in the cytosolic fraction and expression of the apoptosis-associated mitochondrial 7A6 antigen were demonstrable following photosensitization at nano-molar levels of QLT0074. Evidence of processing of the apoptosis-effector molecules caspase-3, -6, -7, -8 and -9 as well as cleavage of the caspase-3 substrate poly (ADP-ribose) polymerase (PARP) were demonstrable subsequent to cytochrome c release after PDT. Treatment with the anti-oxidant pyrrolidine dithiocarbamate (PDTC) inhibited cytochrome c release, caspase-3 activation and PARP cleavage associated with PDT thereby supporting the contention that QLT0074 induces apoptosis through the generation of reactive oxygen species upon light activation. QLT0074 is a potent photosensitizer with the capacity to directly initiate apoptosis by acting upon mitochondria.

Status of therapies in development for the treatment of age-related macular degeneration

Age-related macular degeneration (AMD) is among the leading causes of visual impairment in the elderly. The FDA has approved only two treatments, laser photocoagulation and Visudyne photodynamic therapy (PDT), approved for the wet form of AMD, a progressive condition characterized by the presence of choroidal neovascularization (CNV). Current pharmaceutical activities aimed at the treatment of wet-type AMD are largely focused on the development of anti-angiogenic drugs that would inhibit further CNV formation or even reduce existing CNV. However, other lines of attack for the treatment of wet AMD include anti-inflammatory agents as well as new PDT agents. This review will summarize ongoing activities for these different approaches.

Mitochondrial release of apoptosis-inducing factor and cytochrome c during smooth muscle cell apoptosis

Photodynamic therapy (PDT) is under investigation for the treatment of intimal hyperplastia in conditions such as atherosclerosis and restenosis. Although smooth muscle cells (SMCs) may be a key target for treatment, the effects of PDT on these cells are poorly characterized. In the present study, apoptosis was induced in primary human aortic SMCs by the combination of the photosensitizer verteporfin and visible light. After PDT, an increase in mitochondrial cytochrome c (cyt c) and apoptosis-inducing factor (AIF) levels were detected in the cytosol immediately and their levels increased steadily up to 2 hours. Cytosolic levels of the pro-apoptotic Bcl-2 family member Bax decreased reciprocally throughout this period, but this change did not occur before cyt c release. Confocal microscopy revealed a diffuse staining pattern of cyt c within apoptotic cells as compared to a distinct mitochondrial staining in normal cells. AIF translocated from mitochondria to the nucleus during the progression of apoptosis. After cyt c release, caspase-9 and caspase-3 processing was visible by 1 hour and caspase-6, -7, and -8 processing was apparent by 2 hours after PDT. In summary, these results demonstrate for the first time the cellular redistribution of mitochondrial AIF during SMC apoptosis, as well as the early release of cyt c and the subsequent activation of multiple caspases during PDT-induced SMC apoptosis.

Benzoporphyrin derivative monacid ring A (Verteporfin) alone has no inhibitory effect on intimal hyperplasia: in vitro and in vivo results

Benzoporphyrin derivative monoacid ring A (Verteporfin, BPD-MA), a photosensitizing drug, has been suggested as having inhibitory effects on smooth muscle cell (SMC) proliferation in rabbit aortic intimal injuries. The effect of BPD-MA on vascular SMCs in the absence of light stimulation in vitro and in vivo was studied using models of intimal hyperplasia. Human SMCs were incubated with BPD-MA for 4 h in darkness. A small (20%) but significant decrease in viability (n =42,p < .05) was noted for BPD-MA concentrations above 15 microg/mL. This was an all-or-none phenomenon with no further decrease in viability at higher concentrations. Treatment with BPD-MA was also carried out in vivo using a balloon injury model of intimal hyperplasia in rabbit aortas. Thirty-three rabbits were randomized into five groups and given intravenous BPD-MA (2 mg/kg) according to the following schedule: Group 1 (n = 8), BPD-MA 25 min prior to injury; Group 2 (n = 8), BPD-MA 25 min prior to injury plus a second dose 4 weeks later; Group 3 (n = 4), BPD-MA immediately postinjury; Group 4 (n = 7), BPD-MA immediately postinjury plus a second dose 4 weeks later; or Group 5 (n = 6), no drug (control group). No statistically significant difference was seen in the amount of intimal hyperplasia that developed in the five groups.

Reduced xenograft rejection in rat striatum after pretransplant photodynamic therapy of murine neural xenografts

OBJECT

The goal of this study was to develop a method of reducing neural xenograft rejection by pretreating the graft with photodynamic therapy (PDT).

METHODS

Xenograft cell suspensions were prepared from fetal mouse mesencephalon, after which they were incubated for 30 minutes with various concentrations of a photosensitizer, verteporfin for injection, and light exposure. The xenograft cell suspensions were injected into the dopamine-depleted striata of 40 hemiparkinsonian rats assigned to different treatment groups. Four weeks after transplantation, xenograft function (determined by methamphetamine-induced rotation) and survival (determined by immunohistochemical staining for murine neurons) were compared. Group 1 animals (xenografts pretreated with 25 ng/ml verteporfin) and Group 3 animals (no verteporfin pretreatment, but daily administration of cyclosporin A) had significantly better xenograft survival and function compared with control animals (no pretreatment with verteporfin). Group 2 animals (xenografts pretreated with 250 ng/ml verteporfin) had no significant improvement.

CONCLUSIONS

This work demonstrates improved neural xenograft survival and function when using pretransplant PDT of the graft in a rodent model. The potential benefits of this new therapy are its convenience (one pretransplant treatment) and its compatibility with host immunosuppression.

Release of cytochrome c, Bax migration, Bid cleavage, and activation of caspases 2, 3, 6, 7, 8, and 9 during endothelial cell apoptosis

Although the executioner phase of apoptosis has been well defined in many cell types, the subcellular events leading to apoptosis in endothelial cells remain undefined. In the current study, apoptosis was induced in primary human umbilical venous endothelial cells by the photosensitizer verteporfin and light. Release of mitochondrial cytochrome c into the cytosol was detectable immediately and accumulated over 2 hours after treatment while cytosolic levels of the proapoptotic Bcl-2 family member, Bax, decreased reciprocally over the same time period. Cleavage of another proapoptotic Bcl-2 family member, Bid, was observed by 2 hours after treatment. Although Bid cleavage has been shown to occur as an upstream event responsible for inducing cytochrome c release, we demonstrate that Bid cleavage can also occur after cytochrome c release. Activation of caspases 2, 3, 6, 7, 8, and 9 occurred following the release of cytochrome c, and cleavage of downstream substrates was observed. In summary, endothelial cell death involves the cellular redistribution of Bax and cytochrome c, followed by the activation of multiple caspases which manifest the apoptotic phenotype.

Photodynamic therapy inhibits cell adhesion without altering integrin expression

Adhesion is a primordial cell function that, among others, regulates inflammation, metastasis, and tissue repair. To understand how these events could be affected by photodynamic therapy (PDT), we studied the effects of PDT on human foreskin fibroblast (HFF) adhesion to bovine collagen type I, human vitronectin or fibronectin. PDT, using benzoporphyrin derivative monoacid ring A (verteporfin) as the photosensitizer, inhibited cell adhesion in a drug dose-dependent manner, with no significant difference among matrices. The drug dose that killed 90% of cells within 20 h post-treatment inhibited HFF adhesion by 55%-68%. However, 45 min following PDT, a time period corresponding to that of the adhesion assay, HFF membrane integrity remained unaltered. In addition, cell surface expression of integrins was not modified for at least 2h following PDT. Western blots of cell lysates, using the anti-phosphotyrosine 4G10 monoclonal antibody, revealed that PDT prevented the adhesion-induced phosphorylation of 110-130 kDa proteins. Immunoblots of cell lysates immunoprecipitated with antibodies to focal adhesion kinase suggested that its phosphorylation was suppressed by PDT. These results demonstrate that PDT inhibits cell adhesion and affects integrin signalling without modifying cell membrane integrity or integrin expression.

Biological activities of phthalocyanines. XVII histopathologic evidence for different mechanisms of EMT-6 tumor necrosis induced by photodynamic therapy with disulfonated aluminum phthalocyanine or photofrin

The necrosis of EMT-6 mammary murine tumors induced by photodynamic therapy (PDT) with Photofrin (PII) or disulfonated aluminum phthalocyanine (AlPcS2) was studied. Attention was given to the spontaneous evolution of angiogenesis and necrosis of such tumors in order to determine the most appropriate moment for treatment. On day 6 after tumor cell inoculation, mice were injected with photosensitizer followed by exposure to red light 24 h later, at which time optimal dye concentrations were reached in the tumor. Animals were sacrificed 3 h or 24 h after illumination and tissues were prepared for histology. Prominent cytopathic alterations were already observed at 3 h and there was massive necrosis at 24 h. In the case of PII vascular damage, congestion and hemorrhage were already present at 3 h and these changes account for the subsequent tumor necrosis through hemorrhagic infarction. With AlPcS2 these early vascular alterations were much less evident and only focal at 24 h, suggesting that AlPcS2-PDT mediated tumor necrosis involves to a large extent direct tumor cell damage.

Structure-photodynamic activity relationships of a series of 4-substituted zinc phthalocyanines

Radioiodinated zinc phthalocyanine including [125I]ZnPcI4 and differently sulfonated [65Zn]ZnPcS (ZnPcS4, ZnPcS3, ZnPcS2 and ZnPcS1.75, a mixture of adjacent di and 25% mono) were prepared in order to study cell uptake and release kinetics in EMT-6 cells. The same compounds were evaluated for their in vitro phototoxicity and the biological parameters were compared to partition coefficients to arrive at quantitative structure-activity relationships (QSAR). At 1 microM in 1% serum, at 37 degrees C, all dyes showed rapid cell uptake during the first hour followed by a slow accumulation phase. After 24 h, the highest cellular concentration was observed with the lipophilic ZnPcI4, followed by the amphiphilic ZnPcS2 and ZnPcS1.75. The hydrophilic ZnPcS4 and ZnPcS3 showed lower uptake. Dye release from dye-loaded cells during incubation in dye-free medium could reach up to 60% and was shown to depend mainly on the amount of drug incorporated rather than the type of compound. These results suggest that care should be taken in interpreting dye toxicity data, which involve in vitro cell manipulations in dye-free medium, particularly during in vitro-in vivo protocols. The EMT-6 cell survival after 1 h or 24 h incubation with 1 microM dye in 1% serum followed by exposure to red light was assessed by means of the colorimetric 3-(4,5-dimethylthiazol-2-yl)-diphenyl-tetrazolium bromide (MTT) assay. Photocytotoxicities correlated inversely with the tendencies of the dyes to aggregate. Increased dye uptake by the cells also correlated with their activities, except for the lipophilic ZnPcI4, which showed the highest cell uptake but little phototoxicity. The QSAR between phototoxicity and the log of the partition coefficients (phosphate-buffered saline and n-octanol) gave a parabola with optimal partition values corresponding to the adjacent sulfonated ZnPcS2.

Evaluation of a 99mTc-antimyosin kit for myocardial infarct imaging

The Fab fragment of a mouse monoclonal antibody AM(3-48) that recognizes alpha and beta-heavy chains of human atrial and ventricular myosin and beta-heavy chain of human slow skeletal muscle myosin [CardioVisionTM] was labeled with 99mTc using stannous reductant in a simple, instant kit method. The infarcted heart uptake in dogs of 99mTc-AM(3-48)Fab' was compared with that of established radiopharmaceuticals routinely used for cardiac imaging in humans. The dog infarct was induced by bringing a catheter from the femoral artery to the coronary artery where an artificial blood clot was generated. The 99mTc-AM(3-48)Fab' preparation was selectively taken up by infarcted myocardium, resulting in diagnostic quality images of the infarcted area as early as 6 hour post-injection, rendering CardioVisionTM particularly useful for SPECT imaging. Good agreement was found between the images obtained with 99mTc-Pyrophosphate and those obtained with 99mTc-AM(3-48)Fab', while the infarcted area was clearly delineated as a cold spot with 99mTc-MIBI or 201 Tl-thallous chloride. The biodistribution of 99mTc-AM(3-48)Fab' was also studied in healthy and isoproterenol-infarcted rats, from which dosimetry values in man were extrapolated. The data indicate that the kidneys will receive the highest radiation dose and that they will be the main contributors to the total radiation burden, which was estimated at 0.005 rad/mCi.

Phthalocyanine-induced photohemolysis: structure-activity relationship and the effect of fluoride

Phthalocyanine (Pc) containing A1, Ga or Zn as central metal ligand and substituted with a varying number of sulfonic acid residues as well as additional benzene rings were synthesized and their photodynamic activity was assayed using photohemolysis of human erythrocytes as an endpoint. The Pc derivatives varied > 300-fold in their photodynamic activity. Activity correlated with binding of the dye to the cell, with the exception of some of the amphiphilic dyes where cell uptake was an order of magnitude higher than expected from the observed activity. Fluoride was shown to inhibit A1PcSn-induced photohemolysis. This effect occurred also with other A1Pc and GaPc derivatives, but the concentration of F- required to slow photohemolysis by a factor of two (Ki) varied between 4 microM and 10 mM. Fluorescence spectral studies indicated complex formation between F- and the dye, which was stronger for A1Pc than GaPc derivatives. Ultrastructural studies using scanning electron microscopy showed that the photosensitized cells were converted to spherocytes and that F- prevented this to a large extent.

Photodynamic properties of naphthosulfobenzoporphyrazines, novel asymmetric, amphiphilic phthalocyanine derivatives

Metallo naphthosulfobenzoporphyrazines sulfonated to different degrees (M-NSBP) were prepared, and their potential as photosensitizers for the photodynamic therapy (PDT) of cancer was evaluated. M-NSBP can be viewed as hybrid molecules between sulfophthalocyanines and naphthalocyanines resulting in distinct differences in the absorption spectra between the mono-through tetrasulfonated derivatives. This feature greatly facilited their purification. Using V-79 Chinese hamster cells in vitro, the disulfonated derivatives were found slightly more photoactive than the hydrophilic trisulfonated derivatives while the monosulfonated derivative was inactive, in spite of a sixfold higher cell uptake. In the case of the di- and trisulfonated derivatives, differences in phototoxicity correlated well with their relative cell uptake. Substitution of Al for Zn had little effect on the extent of phototoxicity of the M-NSBP. In vitro PDT of the EMT-6 cells after in vivo dye administration, revealed a similar potency for direct cell killing between the di- and trisulfonated AlOH-NSBP, while the monosulfonated analog was inactive. PDT with the amphiphilic disulfonated AlOH-NSBP on the EMT-6 mammary tumor in BALB/c mice induced a significant tumor response, while the monosulfonated derivative was much less active.

Mixed acenannellated metallotetraazaporphins: a new class of amphiphilic photosensitizers for the photodynamic therapy of cancer

The first synthesis of amphiphilic mixed acenannellated metallotetraazaporphins compounds, designed with the aim of improving cell membrane penetration, is described and the preliminary results on their photocytotoxicity are presented.