for people ages 55 years and up (full criteria)
at Sacramento, California and other locations
study started
estimated completion



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

HORIZON: A Phase II, Open-label, Outcomes-assessor Masked, Multicentre, Randomised, Controlled 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


This is a Phase 2, open-label, outcomes-assessor masked, multicentre, randomised, controlled study to evaluate the safety and efficacy of two doses of GT005 administered as a single subretinal injection in subjects with GA secondary to AMD. The trial includes a screening period of up to 8 weeks and a 96-week study period. Subjects will be randomised to one of two groups; GT005 or the untreated control group.


Dry Age-related Macular Degeneration Geographic atrophy Retinal disease Eye disease Retinal degeneration Macular atrophy Macular Degeneration GT005: Medium Dose GT005: High Dose


You can join if…

Open to people ages 55 years and up

  1. Able and willing to give written informed consent
  2. Age ≥55 years
    1. In Stage 1: 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; b. In

Stage 2: Have a clinical diagnosis of GA secondary to AMD in the study eye, as determined by the Investigator, that is non-foveal, as determined by the central reading centre, or has a CFI rare variant genotype and meets inclusion criteria 3a, and a diagnosis of AMD in the contralateral eye (except if monocular)

  1. GA lesion(s) within an acceptable size on FAF, in the study eye
  2. The GA lesion in the study eye must reside completely within the FAF image
  3. Up to 25% of the enrolled study population are permitted to have CNV in the fellow eye
  4. Have a BCVA of ≥24 letters (6/95 or 20/320 Snellen acuity equivalent), using ETDRS charts, in the study eye
    1. In Stage 1: Meet one of the pre-specified AMD genetic subgroup criteria; b. In

Stage 2: Genotyping is not required for study eligibility

  1. Able to attend all study visits and complete the study procedures
  2. . Women of child-bearing potential must have a negative pregnancy test within 2 weeks prior to randomisation (not required for postmenopausal women) or provide documentation of being surgically sterilised

You CAN'T join if...

    1. In Stage 1: Carriers of excluded genetic variants; b. In Stage 2: Subjects are excluded if they have a clinical diagnosis of Stargardt Disease or other retinal dystrophies
  1. Have a history, or evidence, of CNV in the study eye
  2. Presence of moderate/severe or worse non-proliferative, diabetic retinopathy in the study eye
  3. Have history of vitrectomy, sub-macular surgery, or macular photocoagulation in the study eye
  4. History of intraocular surgery in the study eye within 12 weeks prior to Visit 1
  5. Have clinically significant cataract that may require surgery during the study period in the study eye
  6. Presence of moderate to severe glaucomatous optic neuropathy, uncontrolled intraocular pressure (IOP), despite use of two or more topical agents; or a history of glaucoma-filtering or valve surgery
  7. Axial myopia of greater than -8 diopters in the study eye
  8. Have received any investigational product 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
  9. . Have received a gene or cell therapy at any time.
  10. . Have a contraindication to the protocol specified corticosteroid regimen
  11. . Are unwilling to use two forms of contraception (one of which being a barrier method) for 90 days post-dosing, if relevant
  12. . 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
  13. . 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


  • University of California- Davis Medical Group Eye Center accepting new patients
    Sacramento California 95817 United States
  • Byers Eye Institute at Stanford accepting new patients
    Palo Alto California 94303 United States


accepting new patients
Start Date
Completion Date
Gyroscope Therapeutics Limited
Sign up for this study
Phase 2 Macular Degeneration Research Study
Study Type
Expecting 250 study participants
Last Updated