EXPLORE: A Phase II Study to Evaluate the Safety and Efficacy of Two Doses of GT005


Trial ID: NCT04437368


The purpose of this clinical study is to evaluate the safety and efficacy of two doses of GT005 administered as a single subretinal injection in subjects with geographic atrophy secondary to age-related macular degeneration (AMD).

Official Title

EXPLORE: A Phase II, Outcomes Assessor-masked, Multicentre, Randomised Study to Evaluate the Safety and Efficacy of Two Doses of GT005 Administered as a Single Subretinal Injection in Subjects With Geographic Atrophy Secondary to Age-related Macular Degeneration

Stanford Investigator(s)


Inclusion Criteria:

   1. Able and willing to give written informed consent

   2. Age ≥55 years

   3. Have a clinical diagnosis of GA secondary to AMD in the study eye, as determined by
   the Investigator, and a diagnosis of AMD in the contralateral eye (except if the
   subject is monocular)

   4. Have GA lesion(s) total size between or equal to 1.25mm2 to 17.5mm2 in the study eye

   5. The GA lesion(s) in the study eye must reside completely within the FAF image

   6. Up to 25% of the enrolled study population are permitted to have CNV in the fellow
   eye, defined as either:

      1. Non-exudative/sub-clinical fellow eye CNV identified at Screening, or

      2. Known history of fellow eye CNV with either ≥2 years since diagnosis or with no
      active treatment required in 6 months prior to Screening

   7. Have a BCVA of 24 letters (6/95 and 20/320 Snellen acuity equivalent) or better, using
   ETDRS charts, in the study eye

   8. Part 1 Only: Subjects carrying a CFI rare variant genotype (minor allele frequency of
   ≤1%) previously associated with low serum CFI or subjects carrying an unreported CFI
   rare variant genotype that have tested to have a low serum CFI

   9. Able to attend all study visits and complete the study procedures

10. Women of child-bearing potential must have a negative pregnancy test within 2 weeks
   prior to randomisation. A pregnancy test is not required for postmenopausal women
   (defined as being at least 12 consecutive months without menses) or those surgically
   sterilised (those having a bilateral tubal ligation/bilateral salpingectomy, bilateral
   tubal occlusive procedure, hysterectomy, or bilateral oophorectomy)

Exclusion Criteria:

   1. Subjects who have a clinical diagnosis of Stargardt Disease or other retinal
   dystrophies, confirmed by the central reading centre

   2. Have a history, or evidence, of CNV in the study eye

   3. Presence of moderate/severe or worse non-proliferative diabetic retinopathy in the
   study eye

   4. Have history of vitrectomy, sub-macular surgery, or macular photocoagulation in the
   study eye

   5. History of intraocular surgery in the study eye within 12 weeks prior to Screening
   (Visit 1). Yttrium aluminium garnet capsulotomy is permitted if performed >10 weeks
   prior to Visit 1

   6. Have clinically significant cataract that may require surgery during the study period
   in the study eye

   7. Presence of moderate to severe glaucomatous optic neuropathy in the study eye;
   uncontrolled IOP despite the use of two or more topical agents; a history of
   glaucoma-filtering or valve surgery is also excluded

   8. Axial myopia of greater than -8 dioptres in the study eye

   9. Have any other significant ocular or non-ocular medical or psychiatric condition
   which, in the opinion of the Investigator, may either put the subject at risk or may
   influence the results of the study

10. Have a contraindication to specified protocol corticosteroid regimen

11. Have received any investigational and/or approved product(s) for the treatment of GA
   within the past 6 months, or 5 half-lives (whichever is longer) other than nutritional
   supplements such as the age-related eye disease study (AREDS) formula in the study eye
   or systemically

12. Have received a gene or cell therapy at any time

13. Are unwilling to use two forms of contraception (one of which being a barrier method)
   for 90 days post-dosing, if relevant

14. Active malignancy within the past 12 months, except for: appropriately treated
   carcinoma in situ of the cervix, non-melanoma skin carcinoma, or prostate cancer with
   a stable prostate-specific antigen (PSA) ≥12 months


drug: GT005; Low Dose

drug: GT005; High Dose


Contact Information

Stanford University
School of Medicine
300 Pasteur Drive
Stanford, CA 94305