Geographic AtrophyPhase 2NCT07606365
A Study in Adults With Geographic Atrophy
A Phase 2 study testing STL303 in people with Geographic Atrophy, run by Sitala Bio LTD at 56 sites in 7 countries.
Trial summary
The purpose of this clinical research study is to look at how safe STL303 is and whether it works when given to people with Geographic Atrophy (GA) secondary to Age-related Macular Degeneration (AMD). Read more about this study
- Who is it for?
- Ages 60 years and older
- Conditions the study is for
- Geographic Atrophy
- What is being tested?
- STL303
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 300 participants
- Where
- 56 sitesin 7 countries
- Study dates
- 11 Sep 2026to Aug 2029
- Phase
- Phase 2
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 60 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- The study eye must meet all inclusion criteria. If both eyes meet the inclusion criteria, the eye with the better visual acuity at the Screening visit will be designated as the study eye. If both eyes have the same visual acuity, the right eye will be selected as the study eye.
- Participants ≥60 years of age at the time of Screening (signing the ICF).
- Diagnosis of non-exudative AMD in both eyes, with confirmed presence of phenotypic hallmarks of AMD such as hard and/or soft drusen.
- The GA lesion in the study eye must meet the following criteria as determined by the central Reading Centre's assessment at Screening:
- Total GA area must be ≥2.5 and ≤10.16 mm2 (1 and 4 DA, respectively) as measured using SD-OCT.
- If GA is multifocal, at least one focal lesion must be ≥1.25 mm2 (0.5 DA), with the overall aggregate area of GA, as specified above in 3a.
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- The entire GA lesion must be completely visualised on the 6 × 6 mm fovea-centred OCT scan and must be able to be imaged in its entirety and not contiguous with any areas of peripapillary atrophy.
- The entire EZ loss border must be completely visualised on the 6 × 6 mm fovea centred OCT scan as determined by the central Reading Centre's assessment at Screening; in cases where the EZ loss border is close to the grid boundary, a grid centred on the atrophic area may be used at the Baseline visit (as advised by the Reading Centre).
- All GA lesions must be at least 150 μm from foveal centre.
- Confirmed presence of any pattern of hyper-autofluorescence in the junctional zone of GA; absence of hyper-autofluorescence is exclusionary.
- BCVA by Early Treatment Diabetic Retinopathy Study (ETDRS) score of ≥55 letters (Snellen equivalent ≥20/70) in the study eye at the Screening visit and Baseline visit.
- Low luminance visual acuity (LLVA) by ETDRS score of ≥10 letters in the study eye at the Screening visit and Baseline visit.
- Meets the following criteria related to microperimetry:
- Able to detect fixation target.
- Fixation losses must be ≤20%.
- Participant is willing and able to undertake microperimetry assessment in the opinion of the Investigator.
- Able to take IMP or have an appropriate designee who can administer the IMP (i.e., a capable family member or caregiver).
- Able to provide written informed consent and willing to comply with all site visits, examinations, daily IMP administrations and dosing diary entries, and other conditions of the study protocol.
- Adequate clarity of ocular media, adequate pupillary dilation, and fixation to permit the collection of good quality images as determined by the Investigator.
- The fellow eye may have any of the following: AMD without GA, AMD with GA, or foveal GA (ongoing treatment with complement inhibitor therapies in the fellow eye is allowed).
- Vaccination against Neisseria meningitidis and Streptococcus pneumoniae infection are required at least two weeks prior to the start of the treatment with STL303.
- If not received previously, vaccination against Haemophilus influenzae type b infection should be given, if available and according to local regulations.
- Body mass index (BMI) ≥18 kg/m2 to ≤40 kg/m2.
- Participants of childbearing potential (POCBP) must use an appropriate birth control if not confirmed postmenopausal; male participants with partners of childbearing potential must agree to use highly effective contraception methods during the study and for 1 month after the last dose of the IMP.
- Participants must agree to refrain from donating gametes during the duration of the study and for 1 month after the last dose of the IMP.
Who cannot join
- Atrophic retinal disease of causality other than AMD including myopia-related maculopathy and macular dystrophies such as pattern dystrophy and Stargardt disease in either eye.
- Evidence of ongoing exudative AMD, polypoidal choroidal vasculopathy, or macular neovascularisation in either eye by history, OCT, fluorescein angiography (FA) or optical coherence tomography angiography (OCTA) as determined by the Reading Centre (prior IVT treatment for CNV is permitted in the fellow eye so long as the last injection was more than two years previously).
- Previous treatment with any ocular photodynamic therapy or laser coagulation to the macula in the study eye.
- Presence of active/current retinal vein occlusion in the study eye.
- Presence of vitreous haemorrhage in the study eye.
- History of retinal detachment in the study eye.
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- Ocular conditions - either eye:
- Presence of at least moderate non-proliferative diabetic retinopathy (or worse) in either eye (a history of diabetes mellitus without retinopathy and mild non-proliferative diabetic retinopathy is not a criterion for exclusion).
- Presence of any other retinal pathology that, in the opinion of the Investigator, would confound the diagnosis or assessment of GA or would make follow-up not feasible.
- History of herpetic infection in either eye.
- Active uveitis and/or vitritis (grade trace or above) in either eye.
- History of idiopathic or autoimmune-associated uveitis in either eye.
- Active infectious conjunctivitis, keratitis, scleritis, or endophthalmitis in either eye.
- Spherical equivalent of the refractive error demonstrating >6 diopters of myopia or an axial length >26 mm in either eye.
- Intraocular surgery (including lens replacement surgery) within 3 months prior to randomisation in either eye.
- Yttrium Aluminium Garnet (YAG) laser in either eye within 1 month prior to randomisation.
- History of infection with Neisseria meningitidis, Streptococcus pneumoniae or Haemophilus influenzae type b despite vaccination.
- History or known human immunodeficiency virus (HIV), hepatitis B virus (HBV), or hepatitis C virus (HCV)-positivity (unless treated [for HBV and HCV only]) and achieved sustained viral response with negative polymerase chain reaction (PCR).
- Known ongoing immunodeficiency with or without treatment.
- Previous participation in a retinal gene therapy clinical study where the gene therapy was delivered to either eye.
- History of any prior IVT treatment for any indication other than AMD in either eye. Prior IVT treatment for CNV is permitted in the fellow eye so long as the last injection was more than two years previously.
- Any prior treatment for AMD in the study eye (for example, surgical, radiation, thermotherapeutic, or laser intervention), except oral supplements or minerals; prior treatment with Izervay or Syfovre is allowed in the study eye so long as 6 months have elapsed since the last treatment and so long as the participant did not experience any ocular inflammation or adverse events during the treatment with either Izervay or Syfovre. Ongoing treatment with Izervay or Syfovre is permitted in the fellow eye.
- Usage of systemic immunosuppressants or other immunomodulatory drugs within 90 days prior to the first administration or within 5 half-lives of the drug (whichever is longer), specifically including but not limited to cyclophosphamide, rituximab, infliximab, mycophenolate mofetil, cyclosporine, tacrolimus, sirolimus, systemic corticosteroids (inhaled or topical corticosteroids, or corticosteroids directly injected into the joints are allowed).
- Previous treatment with other systemic complement inhibitors within 30 days prior to the first dose, or within 5 half-lives of the drug, or within the potential period of residual effects from previous clinical studies, such as anti-sense oligonucleotide (ASO) or ribonucleic acid interference (RNAi), whichever is longer.
- Participants with any unstable or clinically significant medical condition that, in the opinion of the Investigator, could pose a risk of complications or interfere with participation during the course of the study.
- Participants with prolonged corrected QT interval (QTc) at Screening or at Baseline (QT interval corrected using Fridericia's formula [QTcF] >480 ms).
- Participants with clinically-relevant cardiac events within the last 2 years.
- Participants with significantly abnormal liver function at Screening or at Baseline: any parameter of ALT, AST, gamma glutamyl transferase (GGT) or alkaline phosphatase (ALP) >3 × upper limit of normal (ULN); serum bilirubin total >1.5 × ULN.
- Platelet count <75000 cells/mm3.
- Haemoglobin value <8 gm/dL.
- History of end stage liver or kidney disease requiring dialysis or transplant.
- History of hypersensitivity to any of the study treatments or excipients or to drugs of similar chemical classes or clinically relevant sensitivity to fluorescein dye as assessed by the Investigator.
- History of alcohol or drug abuse within the last 5 years.
- Ongoing treatment with cytochrome P450 2C8 (CYP2C8) inhibitors, or inducers or strong P-glycoprotein inhibitors.
- Ongoing participation in any other clinical study.
Trial locations and contacts
56 sites in 7 countries. Contact the study team or a site near you to ask about taking part.
56 sites in 7 countries
United States16 sites, 16 recruiting
- Not yet recruiting
Northeast Wisconsin Retina Associates
Appleton, Wisconsin, 54914
Swati Agarwal Sinha
- Not yet recruiting
Retina Specialists of Colorado
Aurora, Colorado, 80012
Michael Jansen
- Not yet recruiting
California Retina Consultants
Bakersfield, California, 93309
Dilsher Dhoot
- Not yet recruiting
Retina Consultants of Texas
Bellaire, Texas, 77401
David Brown
- Not yet recruiting
Retina-Vitreous Associates Medical Group
Beverly Hills, California, 90211
Homayoun Tabandeh
- Recruiting
Star Vision Research
Burleson, Texas, 76028
Courtney Crawford
- Recruiting
Erie Retina Research
Erie, Pennsylvania, 16507
David Almeida
- Not yet recruiting
Cumberland Valley Retina Consultants,P.C.
Hagerstown, Maryland, 21740
Allen Hu
- Not yet recruiting
Mid Atlantic Retina Specialists
Hagerstown, Maryland, 21740
Adam Gerstenblith
- Not yet recruiting
Long Island and Queens Vitreoretinal Consultants of NY, P.C.
Hauppauge, New York, 11788
Brett Rosenblatt
- Not yet recruiting
University Retina and Macula Associates, P.C.
Lemont, Illinois, 60439
Veeral Sheth
- Not yet recruiting
Tennessee Retina, PC
Nashville, Tennessee, 37203
Carl Awh
- Not yet recruiting
Retina Consultants of Texas
Schertz, Texas, 78154
Jeremiah Brown
- Not yet recruiting
Ophthalmic Consultants of Boston
Waltham, Massachusetts, 02451
Chirag Shah
- Not yet recruiting
Retina Group of New England, PC
Waterford, Connecticut, 06385
Nauman Chaudhry
- Not yet recruiting
Eye Clinic of Wisconsin
Wausau, Wisconsin, 54403
Deepak Sambhara
Argentina11 sites, 11 recruiting
- Not yet recruiting
Buenos Aires Macula S.A
Buenos Aires, Buenos Aires, 1061
- Not yet recruiting
Centro Medico Viamonte SRL
Buenos Aires, Buenos Aires, C1120AAC
- Not yet recruiting
Hospital Britanico de Buenos Aires
Buenos Aires, Ciudad Autonoma Buenos Aires, 1008
- Not yet recruiting
Instituoto Oftalmologico de Buenos Aires S.A.
Buenos Aires, Ciudad Autonoma Buenos Aires, C1056
- Not yet recruiting
Centro Oftalmologico Dr. Charles S.A.
Buenos Aires, Ciudad Autonoma Buenos Aires, C1121ABB
- Not yet recruiting
Centro Privado de Ojos
Ciudad Autonoma Buenos Aires, Ciudad Autonoma Buenos Aires, C1033AAW
- Not yet recruiting
IMOC Instituto de Microcirugia Ocular Cordoba
Córdoba, Córdoba Province, X5000
- Not yet recruiting
Centrovision Mendoza SA
Mendoza, Mendoza Province, 5500
- Not yet recruiting
Centro de Ojos Quilmes
Quilmes, Buenos Aires, 1878
- Not yet recruiting
Grupo Laser Visión - Rosario Eximer Laser Visión
Rosario, Santa Fe Province, 2000
- Not yet recruiting
Centro de la Vision
Salta, Salta Province, 4400
Poland10 sites, 10 recruiting
- Not yet recruiting
Szpital Swietego Lukasza S. A.
Bielsko-Biala, 43-309
- Not yet recruiting
Specjalistyczny Osrodek Okulistyczny Oculomedica
Bydgoszcz, 00-189
- Not yet recruiting
Prywatna Klinika Okulistyczna OFTALMIKA
Bydgoszcz, 85-631
- Not yet recruiting
Clinical Medical Research Sp. z o.o.
Katowice, 40-156
- Not yet recruiting
Specjalistyczna Praktyka Lekarska Prof. Edward Wylęgała
Katowice, 40-594
- Not yet recruiting
Centrum Medyczne Dietla 19
Krakow, 31-070
- Not yet recruiting
Centrum Diagnostyki i Mikrochirurgii Oka LENS
Olsztyn, 10-424
- Not yet recruiting
Poznanskie Centrum Wzroku sp z o o
Poznan, 60-538
- Not yet recruiting
Centrum Medyczne
Wałbrzych, 58304
- Not yet recruiting
Centrum Zdrowia MDM
Warsaw, 00-189
Australia6 sites, 6 recruiting
- Not yet recruiting
Adelaide Eye and Retina Centre
Adelaide, South Australia, 5000
- Recruiting
Cerulea Pty Ltd
East Melbourne, Victoria, 3002
- Not yet recruiting
Royal Melbourne Hospital
Parkville, Victoria, 3050
- Not yet recruiting
Queensland Eye Institute
South Brisbane, Queensland, 4101
- Not yet recruiting
Sydney Eye Hospital
Sydney, New South Wales, 2000
- Not yet recruiting
Sydney West Retina
Westmead, New South Wales, 2145
Switzerland6 sites, 6 recruiting
- Not yet recruiting
Ente Ospedaliero Cantonale
Bellinzona, 6500
- Not yet recruiting
Berner Augenklinik
Bern, 3007
- Not yet recruiting
Augenarzte Bern Zentrum Marktgasse
Bern, 3011
- Not yet recruiting
Vista Augenklinik Binningen
Binningen, 4102
- Not yet recruiting
Swiss Visio Montchoisi
Lausanne, 1006
- Not yet recruiting
Stadtspital Triemli
Zurich, 8063
United Kingdom4 sites, 4 recruiting
- Not yet recruiting
University Hospitals of Leicester NHS Trust
Leicester, Leicestershire, LE5 4PW
- Not yet recruiting
The Retina Clinic London
London, Greater London, W1G 7LB
- Not yet recruiting
Royal Victoria Infirmary
Newcastle upon Tyne, Tyne & Wear, NE1 4LP
- Not yet recruiting
Southampton General Hospital
Southampton, Hampshire, SO16 6YD
Czechia3 sites, 3 recruiting
- Not yet recruiting
OFTEX, s.r.o.
Pardubice, Prague, 530 02
- Not yet recruiting
Fakultni nemocnice Kralovske Vinohrady
Prague, Prague, 100 34
- Not yet recruiting
Axon Clinical s.r.o.
Prague, Prague, 150 00
About this study
Official title: A Phase 2, Multicentre, Randomised, Double-masked, Placebo-controlled, Parallel-group, Dose-range Finding Study, to Assess the Efficacy and Safety of Oral STL303 in Adults With Geographic Atrophy Secondary to Age-related Macular Degeneration
The purpose of this clinical research study is to look at how safe STL303 is and whether it works when given to people with Geographic Atrophy (GA) secondary to Age-related Macular Degeneration (AMD). Geographic atrophy secondary to AMD is a condition where cells in the back part of the eye slowly die, causing a blurry, or missing spot in the centre of vision.
Read the detailed description
This study is designed as a randomized, multi-center, double-masked, dose-range finding study to characterize the efficacy and safety of STL303.
- Conditions
- Geographic Atrophy
- Being tested
- STL303, Placebo
- Keywords
- Age-Related Macular Degeneration, Geographic Atrophy
- Medical subject headings
- Geographic Atrophy, Macular Degeneration
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
STL303Drug
STL303 arm participants will receive a specific dose of STL303
PlaceboDrug
Placebo arm participants will receive placebo
| Study group | Role | What they receive |
|---|---|---|
| STL303 dose level 1 | Experimental | Participants will receive STL303 dose level 1 Receives: Drug: STL303 |
| STL303 dose level 2 | Experimental | Participants will receive STL303 dose level 2 Receives: Drug: STL303 |
| Placebo | Placebo comparator | Participants will receive placebo Receives: Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Reduction of rate of total EZ area loss
Rate of change in the area of photoreceptor loss
Measured: From baseline to Week 52
Secondary outcomes (8)
Number of reported treatment-emergent adverse events (TEAE) and serious adverse events (SAEs)
Assess safety and tolerability of STL303
Measured: Baseline to week 108
Change in Retinal sensitivity
Mesopic microperimetry using participant-customised peri-lesional grid.
Measured: From enrolment to end of treatment at week 104
Rate of disease progression (photoreceptor loss)
Rate of change in the area of photoreceptor loss (defined as ellipsoid zone to retinal pigment epithelium thickness of 0 μm) in the study eye, as assessed by spectral-domain optical coherence tomography (SD-OCT)
Measured: From enrolment to end of treatment at week 104
Change in Vision-Related Quality of Life
Change from baseline in the National Eye Institute 25 item Visual Functioning Questionnaire (NEI VFQ-25). Range: 0-100, where higher scores indicate better vision-related quality of life.
Measured: From Baseline to end of treatment at week 104
Maximum serum concertation at steady-state (Cmax, ss) of STL303
Measure maximum plasma concentration at steady-state (Cmax, ss) at steady state.
Measured: Weeks 0, 4, 12, 26, 52, 78, and 104 pre and 2 hours post dose.
Determine pharmacodynamic profile of STL 303
Change from baseline in complement alternative pathway (AP) functional activity as measured by the Wieslab assay in serum
Measured: Weeks 0, 4, 12, 26, 52, 78 and 104 pre and 2 hours post dose.
Trough plasma concentration at steady-state of STL303
Measure trough plasma concentration at steady-state (Cmin, ss /Ctrough, ss),
Measured: Weeks 0, 4, 12, 26, 52, 78, and 104 pre and 2 hours post dose.
Area under plasma concentration-time curve for STL303
Measure the area under the plasma concentration-time curve over one dosing interval at steady state (AUCtau)
Measured: Weeks 0, 4, 12, 26, 52, 78, and 104 pre and 2 hours post dose.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted26 May 2026
- Study start11 Sep 2026
- Primary completionJul 2028 (estimated)
- Study completionAug 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Geographic AtrophyStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 300 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Sitala Bio LTD
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07606365
- Sponsor's protocol ID
- STL303-202
- Status last verified
- Sep 2026
- First submitted
- 12 May 2026
- Last updated
- 21 Sep 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No: Individual participant data (IPD) will not be shared because participant consent and ethics approvals do not permit public data sharing. A clinical study report will be prepared at the end of the study and result will be shared with research sites and investigators will be able to discuss results with participants if needed.