A Phase 2 Evaluation of Anti-VEGF Therapy for Diabetic Macular Edema: Bevacizumab (Avastin)

NCT ID: NCT00336323

Last Updated: 2016-08-26

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: PHASE2
• Total Enrollment: 121 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2006-06-30
• Study Completion Date: 2008-02-29

Brief Summary

This study will provide preliminary data on the dose and dose interval related effects of intravitreally administered Avastin on retinal thickness and visual acuity in subjects with Diabetic Macular Edema (DME) to aid in planning a phase 3 trial.

In addition, this study will provide preliminary data on the safety of intravitreally administered Avastin in subjects with DME.

Detailed Description

Diabetic retinopathy is a major cause of visual impairment in the United States. Diabetic macular edema (DME) is a manifestation of diabetic retinopathy that produces loss of central vision. Data from the Wisconsin Epidemiologic Study of Diabetic Retinopathy (WESDR) estimate that after 15 years of known diabetes, the prevalence of diabetic macular edema is approximately 20% in patients with type 1 diabetes mellitus (DM), 25% in patients with type 2 DM who are taking insulin, and 14% in patients with type 2 DM who do not take insulin.

In a review of three early studies concerning the natural history of diabetic macular edema, Ferris and Patz found that 53% of 135 eyes with diabetic macular edema, presumably all involving the center of the macula, lost two or more lines of visual acuity over a two year period. In the Early Treatment Diabetic Retinopathy Study (ETDRS), 33% of 221 untreated eyes available for follow-up at the 3-year visit, all with edema involving the center of the macula at baseline, had experienced a 15 or more letter decrease in visual acuity score (equivalent to a doubling of the visual angle, e.g., 20/25 to 20/50, and termed "moderate visual loss").

In the ETDRS, focal photocoagulation (direct treatment to microaneurysms and grid treatment to diffuse edema) of eyes with clinically significant macular edema (CSME) reduced the risk of moderate visual loss by approximately 50% (from 24% to 12%, three years after initiation of treatment). Therefore, 12% of treated eyes developed moderate visual loss in spite of treatment. Furthermore, approximately 40% of treated eyes that had retinal thickening involving the center of the macula at baseline still had thickening involving the center at 12 months, as did 25% of treated eyes at 36 months.

Although several treatment modalities are currently under investigation, the only demonstrated means to reduce the risk of vision loss from diabetic macular edema are laser photocoagulation, as demonstrated by the ETDRS, intensive glycemic control, as demonstrated by the Diabetes Control and Complications Trial (DCCT) and the United Kingdom Prospective Diabetes Study (UKPDS) and blood pressure control, as demonstrated by the UKPDS. In the DCCT, intensive glucose control reduced the risk of onset of diabetic macular edema by 23% compared with conventional treatment. Long-term follow-up of patients in the DCCT show a sustained effect of intensive glucose control, with a 58% risk reduction in the development of diabetic macular edema for the DCCT patients followed in the Epidemiology of Diabetes Interventions and Complications Study.

The frequency of an unsatisfactory outcome with respect to proportion with vision improvement following laser photocoagulation in some eyes with diabetic macular edema has prompted interest in other treatment modalities. One such treatment is pars plana vitrectomy. These studies suggest that vitreomacular traction, or the vitreous itself, may play a role in increased retinal vascular permeability. Removal of the vitreous or relief of mechanical traction with vitrectomy and membrane stripping may be followed by substantial resolution of macular edema and corresponding improvement in visual acuity. However, this treatment may be applicable only to a specific subset of eyes with diabetic macular edema that have a component of vitreomacular traction contributing to the edema. It also requires a complex surgical intervention with its inherent risks, recovery time, and expense. Other treatment modalities such as pharmacologic therapy with oral protein kinase C inhibitors and use of intravitreal corticosteroids are under investigation. The use of antibodies targeted at vascular endothelial growth factor (VEGF), such as in the current study, is another treatment modality that has generated considerable interest, and is currently being investigated in phase 3 trials of choroidal neovascularization in age-related macular degeneration (with pegaptanib or ranibizumab) or diabetic macular edema (with pegaptanib).

Increased VEGF levels have been demonstrated in the retina and vitreous of human eyes with diabetic retinopathy. VEGF, also known as vascular permeability factor, has been demonstrated to increase vessel permeability by increasing the phosphorylation of tight junction proteins, and has been shown to increase retinal vascular permeability in in vivo models. Anti-VEGF therapy, therefore, may represent a useful therapeutic modality which targets the underlying pathogenesis of diabetic macular edema.

Bevacizumab is currently approved for the treatment of metastatic colorectal cancer, and published case reports and widespread clinical use have suggested its efficacy in the treatment of neovascular age-related macular degeneration and macular edema associated with diabetes and central retinal vein occlusion. To date, no evidence of ocular inflammation or other adverse events has been noted in association with intravitreal injection of bevacizumab. However, a study has not been conducted to evaluate its efficacy and safety. In view of the widespread use of bevacizumab, such a study is important to conduct.

From a public health perspective, an intravitreal bevacizumab study is also important to conduct because of the relatively low cost of the bevacizumab drug. As noted earlier, bevacizumab is marketed for systemic use for colon cancer. The dose used in the eye is a fraction of the systemic dose and costs $25 to $50 per dose.

The two doses of bevacizumab being evaluated in this study will be 1.25 mg, which is the dose that has most commonly been used in clinical practice, and 2.5 mg, which has also been used though less commonly. A lower dose than 1.25 mg would create difficulties with dilution and the accuracy of injection of a small volume.

The optimal interval for the bevacizumab doses is not known. Six weeks has been selected for this study as it is not believed that the effect will last longer than this. Retinal thickening and visual acuity will be measured at 3 and 6 weeks to provide the requisite information to judge the duration of effect.

There is expected to be a beneficial cumulative effect of multiple doses. A total of two doses, spaced 6 weeks apart, was selected for the study with the primary outcome 3 weeks after the second dose.

The decision as to whether to proceed to a phase 3 trial will be based on the observation of a substantial reduction in retinal thickening in the bevacizumab-treated eyes compared with the laser-treated eyes and at least a suggestion of benefit on visual acuity, plus a safety profile of minimal risk.

Description: The study involves the enrollment of subjects over 18 years of age with diabetic macular edema. Subjects will have one study eye randomly assigned with equal probability (stratified by visual acuity) to one of 5 treatment groups:

Laser photocoagulation at baseline

1.25 mg intravitreal injection of bevacizumab at baseline and 6 weeks

2.5 mg intravitreal injection of bevacizumab at baseline and 6 weeks

1.25 mg intravitreal injection of bevacizumab at baseline (sham injection at 6 weeks)

1.25 mg intravitreal injection of bevacizumab at baseline, laser photocoagulation at 3 weeks, and intravitreal injection of 1.25 mg bevacizumab at 6 weeks

Follow-up includes 10 visits at 4 days, 3 weeks, 6 weeks, 4 days following 6 weeks, 9 weeks, 12 weeks, 18 weeks, 24 weeks, 41 weeks and 70 weeks. At each visit, visual acuity and ocular exams are completed on both eyes, and an OCT is performed on the study eye (except at the 4-day visits).

During the first 12 weeks, no other treatment for DME is given. During weeks 13-24, treatment depends on the response to the treatment given during the first 12 weeks. After 24 weeks, follow-up is for safety and treatment is at the investigator's discretion.

Conditions

Diabetic Retinopathy

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: DOUBLE

Study Groups

1

Laser photocoagulation at baseline

Group Type: ACTIVE_COMPARATOR

Laser Photocoagulation

Intervention Type: PROCEDURE

Laser photocoagulation at baseline; If edema present at 12 weeks, can be treated with 2 intravitreal injections of 1.25 mg bevacizumab spaced 6 weeks apart

2

1.25 mg intravitreal injection of bevacizumab at baseline and 6 weeks

Group Type: EXPERIMENTAL

Bevacizumab

Intervention Type: DRUG

1.25 mg intravitreal injection of bevacizumab at baseline and 6 weeks

3

2.5 mg intravitreal injection of bevacizumab at baseline and 6 weeks

Group Type: EXPERIMENTAL

Bevacizumab

Intervention Type: DRUG

2.5 mg intravitreal injection of bevacizumab at baseline and 6 weeks

4

1.25 mg intravitreal injection of bevacizumab at baseline (sham injection at 6 weeks)

Group Type: EXPERIMENTAL

Bevacizumab

Intervention Type: DRUG

1.25 mg intravitreal injection of bevacizumab at baseline (sham injection at 6 weeks)

5

1.25 mg intravitreal injection of bevacizumab at baseline, laser photocoagulation at 3 weeks, and intravitreal injection of 1.25 mg bevacizumab at 6 weeks

Group Type: EXPERIMENTAL

Bevacizumab

Intervention Type: DRUG

1.25 mg intravitreal injection of bevacizumab at baseline, laser photocoagulation at 3 weeks, and intravitreal injection of 1.25 mg bevacizumab at 6 weeks

Interventions

Laser Photocoagulation

Laser photocoagulation at baseline; If edema present at 12 weeks, can be treated with 2 intravitreal injections of 1.25 mg bevacizumab spaced 6 weeks apart

Intervention Type: PROCEDURE

Bevacizumab

1.25 mg intravitreal injection of bevacizumab at baseline and 6 weeks

Intervention Type: DRUG

Bevacizumab

2.5 mg intravitreal injection of bevacizumab at baseline and 6 weeks

Intervention Type: DRUG

Bevacizumab

1.25 mg intravitreal injection of bevacizumab at baseline (sham injection at 6 weeks)

Intervention Type: DRUG

Bevacizumab

1.25 mg intravitreal injection of bevacizumab at baseline, laser photocoagulation at 3 weeks, and intravitreal injection of 1.25 mg bevacizumab at 6 weeks

Intervention Type: DRUG

Other Intervention Names

Avastin; anti-VEGF drug; Avastin; anti-VEGF drug; Avastin; anti-VEGF drug; Avastin; anti-VEGF drug

Eligibility Criteria

Inclusion Criteria

1. Age >= 18 years

2. Diagnosis of diabetes mellitus (type 1 or type 2)

3. Able and willing to provide informed consent.

EXCLUSION

Subjects can have only one study eye. If both eyes are eligible, the study eye will be selected by the investigator and subject.

The eligibility criteria for a study eye are as follows:

INCLUSION

1. Best corrected E-ETDRS visual acuity letter score of >= 24 (i.e., 20/320 or better) and <= 78 (i.e., 20/32 or worse) within 8 days of randomization.

2. On clinical exam, definite retinal thickening due to diabetic macular edema involving the center of the macula.

3. OCT central subfield >=275 microns within 8 days of randomization.

4. Media clarity, pupillary dilation, and subject cooperation sufficient for adequate fundus photographs.

5. If prior macular photocoagulation has been performed, the investigator believes that the study eye may possibly benefit from additional photocoagulation.

EXCLUSION

The following exclusions apply to the study eye only (i.e., they may be present for the nonstudy eye):

6. Macular edema is considered to be due to a cause other than diabetic macular edema.

7. An ocular condition is present such that, in the opinion of the investigator, visual acuity would not improve from resolution of macular edema (e.g., foveal atrophy, pigmentary changes, dense subfoveal hard exudates, nonretinal condition).

8. An ocular condition is present (other than diabetes) that, in the opinion of the investigator, might affect macular edema or alter visual acuity during the course of the study (e.g., vein occlusion, uveitis or other ocular inflammatory disease, neovascular glaucoma, Irvine-Gass Syndrome, etc.).

9. Substantial cataract that, in the opinion of the investigator, is likely to be decreasing visual acuity by 3 lines or more (i.e., cataract would be reducing acuity to 20/40 or worse if eye was otherwise normal).

10. History of treatment for DME at any time in the past 3 months (such as focal/grid macular photocoagulation, intravitreal or peribulbar corticosteroids, anti-VEGF drugs, or any other treatment).

11. History of panretinal scatter photocoagulation (PRP) within 4 months prior to randomization.

12. Anticipated need for PRP in the 6 months following randomization.

13. History of prior pars plana vitrectomy.

14. History of major ocular surgery (including cataract extraction, scleral buckle, any intraocular surgery, etc.) within prior 6 months or anticipated within the next 6 months following randomization.

15. History of YAG capsulotomy performed within 2 months prior to randomization.

16. Aphakia.

17. Uncontrolled glaucoma (in investigator's judgment).

18. Exam evidence of external ocular infection, including conjunctivitis, chalazion, or significant blepharitis.

FELLOW EYE CRITERIA

The fellow eye must meet the following criteria:

1. Best corrected E-ETDRS visual acuity letter score >= 19 (i.e., 20/400 or better).

2. No anti-VEGF treatment within the past 3 months and no expectation of such treatment in next 3 months.

Exclusion Criteria

4. Significant renal disease, defined as a history of chronic renal failure requiring dialysis or kidney transplant.

5. A condition that, in the opinion of the investigator, would preclude participation in the study (e.g., unstable medical status including blood pressure, cardiovascular disease, and glycemic control).

6. Participation in an investigational trial within 30 days of randomization that involved treatment with any drug that has not received regulatory approval at the time of study entry.

7. Known allergy to any component of the study drug.

8. Blood pressure > 180/110 (systolic above 180 OR diastolic above 110).

9. Major surgery within 28 days prior to randomization or major surgery planned during the next 6 months.

10. Myocardial infarction, other cardiac event requiring hospitalization, stroke, transient ischemic attack, or treatment for acute congestive heart failure within 6 months prior to randomization.

11. Systemic anti-VEGF or pro-VEGF treatment within 3 months prior to randomization.

12. For women of child-bearing potential: pregnant or lactating or intending to become pregnant within the next 6 months.

13. Subject is expecting to move out of the area of the clinical center to an area not covered by another clinical center during the first 6 months of the study.

STUDY EYE CRITERIA

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

National Eye Institute (NEI)

NIH

Sponsor Role: collaborator

Jaeb Center for Health Research

OTHER

Sponsor Role: lead

Responsible Party

Jaeb Center for Health Research (DRCR.net)

Principal Investigators

Ingrid U. Scott, M.D., M.P.H.

Role: STUDY_CHAIR

Penn State College of Medicine

Locations

Loma Linda University Health Care, Dept. of Ophthalmology

Loma Linda, California, United States

Southern California Desert Retina Consultants, MC

Palm Springs, California, United States

California Retina Consultants

Santa Barbara, California, United States

Bay Area Retina Associates

Walnut Creek, California, United States

Retina Vitreous Consultants

Fort Lauderdale, Florida, United States

Central Florida Retina Institute

Lakeland, Florida, United States

Southeast Retina Center, P.C.

Augusta, Georgia, United States

Illinois Retina Associates

Joliet, Illinois, United States

Raj K. Maturi, M.D., P.C.

Indianapolis, Indiana, United States

American Eye Institute

New Albany, Indiana, United States

Retina and Vitreous Associates of Kentucky

Lexington, Kentucky, United States

Paducah Retinal Center

Paducah, Kentucky, United States

Maine Vitreoretinal Consultants

Bangor, Maine, United States

Elman Retina Group, P.A.

Baltimore, Maryland, United States

Retina Consultants of Delmarva, P.A.

Salisbury, Maryland, United States

Ophthalmic Consultants of Boston

Boston, Massachusetts, United States

Joslin Diabetes Center

Boston, Massachusetts, United States

Retina Center, PA

Minneapolis, Minnesota, United States

Charlotte Eye, Ear, Nose and Throat Assoc., PA

Charlotte, North Carolina, United States

Wake Forest University Eye Center

Winston-Salem, North Carolina, United States

Retina Associates of Cleveland, Inc.

Beachwood, Ohio, United States

Retina Northwest, PC

Portland, Oregon, United States

Casey Eye Institute

Portland, Oregon, United States

Penn State College of Medicine

Hershey, Pennsylvania, United States

Retina Consultants

Providence, Rhode Island, United States

Palmetto Retina Center

Columbia, South Carolina, United States

Carolina Retina Center

Columbia, South Carolina, United States

Southeastern Retina Associates, P.C.

Knoxville, Tennessee, United States

West Texas Retina Consultants P.A.

Abilene, Texas, United States

Retina Research Center

Austin, Texas, United States

Texas Retina Associates

Dallas, Texas, United States

Charles A. Garcia, PA & Associates

Houston, Texas, United States

Texas Retina Associates

Lubbock, Texas, United States

University of Washington Medical Center

Seattle, Washington, United States

Countries

United States

References

Diabetic Retinopathy Clinical Research Network; Scott IU, Edwards AR, Beck RW, Bressler NM, Chan CK, Elman MJ, Friedman SM, Greven CM, Maturi RK, Pieramici DJ, Shami M, Singerman LJ, Stockdale CR. A phase II randomized clinical trial of intravitreal bevacizumab for diabetic macular edema. Ophthalmology. 2007 Oct;114(10):1860-7. doi: 10.1016/j.ophtha.2007.05.062. Epub 2007 Aug 15.

Reference Type: RESULT

PMID: 17698196 (View on PubMed)

Scott IU, Bressler NM, Bressler SB, Browning DJ, Chan CK, Danis RP, Davis MD, Kollman C, Qin H; Diabetic Retinopathy Clinical Research Network Study Group. Agreement between clinician and reading center gradings of diabetic retinopathy severity level at baseline in a phase 2 study of intravitreal bevacizumab for diabetic macular edema. Retina. 2008 Jan;28(1):36-40. doi: 10.1097/IAE.0b013e31815e9385.

Reference Type: RESULT

PMID: 18185135 (View on PubMed)

Bhavsar AR, Ip MS, Glassman AR; DRCRnet and the SCORE Study Groups. The risk of endophthalmitis following intravitreal triamcinolone injection in the DRCRnet and SCORE clinical trials. Am J Ophthalmol. 2007 Sep;144(3):454-6. doi: 10.1016/j.ajo.2007.04.011.

Reference Type: DERIVED

PMID: 17765429 (View on PubMed)

Other Identifiers

U10EY018817-03

Identifier Type: NIH

Identifier Source: secondary_id

View Link

U10EY014229-07

Identifier Type: NIH

Identifier Source: secondary_id

View Link

U10EY014231-09

Identifier Type: NIH

Identifier Source: secondary_id

View Link

EY14231, EY14269, EY14229

Identifier Type: -

Identifier Source: secondary_id

NEI-129

Identifier Type: -

Identifier Source: org_study_id