Metformin for the Minimization of Geographic Atrophy Progression in Patients With AMD

Overview

The purpose of this study is to determine whether metformin, an FDA-approved drug for the treatment of type II diabetes, is a safe and effective treatment to decrease the progression of geographic atrophy in non-diabetic patients with Age-related Macular Degeneration (AMD).

Full Title of Study: “METforMIN: Metformin Administration for the Minimization of Geographic Atrophy Progression in Patients With Age-related Macular Degeneration”

Study Type

  • Study Type: Interventional
  • Study Design
    • Allocation: Randomized
    • Intervention Model: Parallel Assignment
    • Primary Purpose: Treatment
    • Masking: Single (Outcomes Assessor)
  • Study Primary Completion Date: April 2020

Detailed Description

This is a phase II, single-blind, randomized, evaluation of the safety and efficacy of metformin use to decrease geographic atrophy (GA) progression in non-diabetic patients with dry Age-related Macular Degeneration (AMD). Approximately 186 study subjects throughout four separate study sites will be randomized in a 1:1 ratio to the treatment group and the observation group. The treatment group will be assigned to the study intervention (oral Metformin) for 18 months while the observation group will receive no intervention for 18 months, instead continuing with standard of care ophthalmic exams and close monitoring of their disease. There will be one additional follow up visit at 24 months. Throughout the 24 month study period, the progression of subjects' GA or drusen growth will be measured via ocular imaging taken at standard of care follow-up examinations, including fundus autofluorescence imaging, optical coherence tomography (OCT), and fundus photography.

Interventions

  • Drug: Metformin

Arms, Groups and Cohorts

  • Experimental: Metformin
    • This arm will be receiving the study drug, Metformin, for the duration of the 18 month study. They will begin this drug on a low dose of Metformin, increasing the dosage in a step-wise fashion to avoid unwanted gastrointestinal discomfort, a common side effect when patients begin taking Metformin. During the 18 month study, subjects assigned to this arm will have 3 follow-up exams after the initial enrollment exam, at 6 month intervals.
  • No Intervention: Observe
    • This arm will maintain standard of care for dry AMD, which is observation. During the 18 month study, subjects assigned to this arm will have 3 follow-up exams after the initial enrollment exam, at 6 month intervals.

Clinical Trial Outcome Measures

Primary Measures

  • Fundus autoflorescence imaging to measure the rate of change in area of geographic atrophy or drusen growth
    • Time Frame: 0 months, 6 months, 12 months, 18 months, 24 months

Secondary Measures

  • Changes in best corrected visual acuity (BCVA)
    • Time Frame: 0 months, 6 months, 12 months, 18 months, 24 months
  • Changes in normal luminance minus low-luminance visual acuity
    • Time Frame: 0 months, 6 months, 12 months, 18 months, 24 months
    • This measure has been shown to correlate well with enlargement of GA
  • Changes in scores over the study period on the National Eye Institute Visual Function Questionnaire 25 (NEI-VFQ-25)
    • Time Frame: 0 months, 18 months
    • The changes in patients’ scores from time of enrollment to final follow-up exam will be compared between the two study arms
  • Ocular safety as measured by the presence of novel intraocular inflammation judged by the investigator to be due to the study drug metformin
    • Time Frame: 0 months, 6 months, 12 months, 18 months, 24 months
    • Subjects assigned to the Metformin study arm will be assessed at each follow-up eye exam to confirm ocular safety of metformin. The Data Safety and Management Board for this study will also assess the safety of metformin at different time points throughout the study. They will formally meet to discuss study subject safety at 25% enrollment and 75% enrollment. The potential for ocular side effects due to metformin is thought to be very low, due to the large number of diabetic patients who take this drug and are followed closely for diabetic retinopathy or other ocular disease.
  • Systemic safety as measured by presence of side effects listed on Metformin drug label as “severe”
    • Time Frame: 0 months, 6 months, 12 months, 18 months, 24 months
    • These include: Infrequent side effects of metformin (severe): Trouble Breathing Rare side effects of metformin (severe): Increased Blood Acidity due to High Levels of Lactic Acid (Lactic acidosis) Low Blood Sugar Megaloblastic Anemia Reaction due to an Allergy Subjects assigned to the Metformin study arm will be assessed for these side-effects at each follow-up eye exam to confirm ocular safety of metformin. The Data Safety and Management Board for this study will also assess the safety of metformin at different time points throughout the study. They will formally meet to discuss study subject safety at 25% enrollment and 75% enrollment.

Participating in This Clinical Trial

Inclusion Criteria

  • Subject must be >/= 55 years of age
  • Subject must have evidence of advanced dry AMD, defined by the characteristic presence of drusen and/or pigmentary changes as well as geographic atrophy
  • Subject must have clear ocular media and adequate pupillary dilation
  • Subject must be able to swallow capsules
  • Study eye must have best corrected visual acuity (BCVA) of 20/20-20/400
  • Subject must be willing and able to pay for monthly prescription of Metformin HCl for 18 months in the event that their insurance carrier will not cover the cost of the drug

Exclusion Criteria

  • Subjects with insufficient baseline size of geographic atrophy, less than 1.25 mm2 (0.5 Macular Photocoagulation Study Disc Areas). GA is defined as one or more well-defined and often circular patches of partial or complete depigmentation of the RPE, typically with exposure of underlying choroidal blood vessels. Even if much of the RPE appears to be preserved and large choroidal vessels are not visible, a round patch of RPE partial depigmentation may be classified as early GA. The GA in the study eye must be able to be photographed in its entirety, and it must not be contiguous with any areas of peripapillary atrophy, which can complicate area measurements.
  • Subjects who are already taking metformin for another purpose
  • Subjects with type 1 or 2 diabetes
  • Subjects with compromised kidney function:
  • Serum creatinine ≥1.5 mg/dL for males and ≥1.4 mg/dL for females
  • Subjects with moderate to severe heart failure (Class III or IV, New York Heart Association Functional Classifications)
  • Subjects with Child's class C cirrhosis
  • Evidence of retinal atrophy due to causes other than atrophic AMD.
  • Subjects who have had anti-VEGF injections or active choroidal neovascularization in the study eye during the last 12 months
  • Current evidence or history of ocular disorders in the study eye that in the opinion of the investigator confounds study outcome measures, including (but not limited to):

1. Non-proliferative diabetic retinopathy involving 10 or more hemorrhages or microaneurysms, or active proliferative diabetic retinopathy

2. Branch or central retinal vein or artery occlusion

3. Macular hole

4. Pathologic myopia

5. Uveitis

6. Pseudovitelliform maculopathy

7. Intraoperative surgery within the last 90 days prior to study eye enrollment

Gender Eligibility: All

Minimum Age: 55 Years

Maximum Age: N/A

Are Healthy Volunteers Accepted: No

Investigator Details

  • Lead Sponsor
    • University of California, San Francisco
  • Collaborator
    • San Francisco Veterans Affairs Medical Center
  • Provider of Information About this Clinical Study
    • Sponsor
  • Overall Official(s)
    • Jay M Stewart, MD, Principal Investigator, University of California, San Francisco
  • Overall Contact(s)
    • Jay M Stewart, MD, 415-206-3123, eyestudy@ucsf.edu

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