EXPLORE: A Phase II Study to Evaluate the Safety and Efficacy of Two Doses of GT005 (EXPLORE)
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ClinicalTrials.gov Identifier: NCT04437368 |
Recruitment Status :
Recruiting
First Posted : June 18, 2020
Last Update Posted : October 5, 2020
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Condition or disease | Intervention/treatment | Phase |
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Dry Age-related Macular Degeneration | Drug: GT005; Dose 1 Drug: GT005; Dose 2 | Phase 2 |
This is a Phase 2, 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 GA secondary to AMD.
The trial includes a screening period of up to 8 weeks followed by a 48-week study period.
Subjects will be randomised to two groups; GT005 or the untreated control group.
Study Type : | Interventional (Clinical Trial) |
Estimated Enrollment : | 75 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Intervention Model Description: | This is a Phase 2, 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 GA secondary to AMD. |
Masking: | Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor) |
Masking Description: | The overall objectives of the study are to evaluate the safety and efficacy (anatomical and functional visual outcomes) of two doses of GT005 in genetically defined subjects with GA due to AMD. |
Primary Purpose: | Treatment |
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 |
Actual Study Start Date : | July 14, 2020 |
Estimated Primary Completion Date : | February 28, 2023 |
Estimated Study Completion Date : | February 28, 2023 |

Arm | Intervention/treatment |
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Experimental: GT005 Dose 1
Approximately 25 subjects are planned, with subjects randomised to GT005 Dose 1.
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Drug: GT005; Dose 1
The study will test two doses of GT005; Dose 1 and Dose 2. |
Experimental: GT005 Dose 2
Approximately 25 subjects are planned, with subjects randomised to GT005 Dose 2.
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Drug: GT005; Dose 2
The study will test two doses of GT005; Dose 1 and Dose 2. |
No Intervention: Untreated control
Approximately 25 subjects are planned, with subjects randomised to untreated control.
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- Progression of geographic atrophy [ Time Frame: 48 weeks ]The change from baseline to Week 48 in GA area as measured by fundus fluorescence (FAF)
- Evaluation of the safety and tolerability of GT005 [ Time Frame: 48 weeks ]Frequency of treatment emergent AEs
- Evaluation of the safety and tolerability of GT005 [ Time Frame: 48 weeks ]Change on ophthalmic examination
- Evaluation of the safety and tolerability of GT005 [ Time Frame: 48 weeks ]Change in imaging modalities
- Evaluation of the safety and tolerability of GT005 [ Time Frame: 48 weeks ]Change in best corrected visual acuity (BCVA)
- Evaluation of the effect of GT005 on retinal anatomical measures [ Time Frame: 48 weeks ]Change in retinal microstructures on spectral domain optical coherence tomography (SD-OCT)
- Evaluation of the effect of GT005 on retinal anatomical measures [ Time Frame: 48 weeks ]Change in presence of area of nascent GA on SD-OCT
- Evaluation of the effect of GT005 on retinal anatomical measures [ Time Frame: 48 weeks ]Change in GA morphology on colour fundus photography (CFP)
- Evaluation of the effect of GT005 on functional measures [ Time Frame: 48 weeks ]Macular sensitivity as assessed by mesopic Microperimetry
- Evaluation of the effect of GT005 on functional measures [ Time Frame: 48 weeks ]Change in BCVA Score via the early treatment for diabetic retinopathy (ETDRS) chart
- Evaluation of the effect of GT005 on functional measures [ Time Frame: 48 weeks ]Change in low luminance difference (LLD) via the ETDRS chart
- Evaluation of the effect of GT005 on visual function [ Time Frame: 48 weeks ]Change in reading performance as assessed by Minnesota low-vision reading test (MNRead) Chart
- Evaluation of the effect of GT005 on visual function [ Time Frame: 48 weeks ]Change in functional reading independence (FRI) index
- Evaluation of the effect of GT005 on patient-reported outcomes [ Time Frame: 48 weeks ]Change in quality of life measured on the Visual Functioning Questionnaire-25 (VFQ-25)

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Ages Eligible for Study: | 55 Years and older (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Inclusion Criteria:
- Able and willing to give written informed consent
- Age ≥55 years
- Have a clinical diagnosis of GA secondary to AMD as determined by the Investigator
- GA lesion(s) within an acceptable size on FAF, in the study eye
- The GA lesion in the study eye must reside completely within the FAF image
- Have a BCVA of 34 letters (6/60 and 20/200 Snellen acuity equivalent) or better, using ETDRS charts, in the study eye
- Serum Complement Factor I level below the lower limit of normal of the selected assay
- Have a rare genetic variant of the CFI gene, defined as a minor allele frequency of <1%
- Able to attend all study visits and complete the study procedures
- Women of child-bearing potential must have a negative pregnancy test within 2 weeks prior to randomisation
Exclusion Criteria:
- Have evidence or history of CNV in either eye
- Presence of moderate/severe or worse non-proliferative diabetic retinopathy in the study eye
- Have history of vitrectomy, sub-macular surgery, or macular photocoagulation in the study eye
- Have clinically significant cataract that may require surgery during the study period in the study eye
- Presence of moderate to severe glaucomatous optic neuropathy in the study eye, uncontrolled intraocular pressure (IOP), use of two or more topical agents to control IOP, or a history of glaucoma-filtering surgery
- Axial myopia of greater than -8 diopters in the study eye
- 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
- Have a contraindication to oral prednisolone/prednisone
- 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 AREDS formula
- Have received a gene or cell therapy at any time
- Are unwilling to use two forms of contraception (one of which being a barrier method) for 90 days post-dosing, if relevant
- Have a history or presence of cutaneous squamous cell carcinoma

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT04437368
Contact: Gyroscope Therapeutics | +441438532142 | clinicaltrials@gyroscopetx.com |
United States, Iowa | |
Wolfe Eye Clinic | Recruiting |
West Des Moines, Iowa, United States, 50266 | |
United States, Massachusetts | |
Ophthalmic Consultants of Boston (OCB) | Recruiting |
Boston, Massachusetts, United States, 02114 | |
United States, Nevada | |
Sierra Eye Associates | Recruiting |
Reno, Nevada, United States, 89502 | |
United States, New York | |
Harkness Eye Institute | Recruiting |
New York, New York, United States, 10032 | |
Retina Association of Western New York | Recruiting |
Rochester, New York, United States, 14620 | |
United States, Ohio | |
Cincinnati Eye Institute | Not yet recruiting |
Cincinnati, Ohio, United States, 45242 | |
United States, Pennsylvania | |
Mid Atlantic Retina | Recruiting |
Philadelphia, Pennsylvania, United States, 19107 | |
United States, Texas | |
The Retina Care Center | Recruiting |
Dallas, Texas, United States, 21209 | |
Germany | |
Universitatsklinikum Tübingen | Recruiting |
Tübingen, Germany, 72076 |
Responsible Party: | Gyroscope Therapeutics |
ClinicalTrials.gov Identifier: | NCT04437368 |
Other Study ID Numbers: |
GT005-02 |
First Posted: | June 18, 2020 Key Record Dates |
Last Update Posted: | October 5, 2020 |
Last Verified: | June 2020 |
Studies a U.S. FDA-regulated Drug Product: | Yes |
Studies a U.S. FDA-regulated Device Product: | No |
Geographic atrophy Retinal disease Eye disease |
Retinal degeneration Macular atrophy Dry age-related macular degeneration |
Macular Degeneration Geographic Atrophy Retinal Degeneration Retinal Diseases Eye Diseases |