NCT06541704 · Regeneron Pharmaceuticals
A Study Investigating Subcutaneously Administered Pozelimab in Combination With Cemdisiran or Cemdisiran Alone in Adult Participants With Geographic Atrophy
(SIENNA)
What this study is about
This study is researching experimental (study) drugs called pozelimab and cemdisiran. The study is focused on participants who have Geographic Atrophy (GA) caused by Age-related Macular Degeneration (AMD). Geographic atrophy is a medical term that refers to later-stage cases of AMD which is an eye condition affecting central vision (what one sees straight ahead).
View original scientific description
This study is researching experimental (study) drugs called pozelimab and cemdisiran. The study is focused on participants who have Geographic Atrophy (GA) caused by Age-related Macular Degeneration (AMD). Geographic atrophy is a medical term that refers to later-stage cases of AMD which is an eye condition affecting central vision (what one sees straight ahead).
Interventions
DRUG
Pozelimab
Subcutaneous (SC) injection
DRUG
Cemdisiran
SC injection
DRUG
Placebo
SC injection
Primary outcome measures
Growth rate (slope) of total GA lesion area (mm^2 /year) from baseline, measured by Fundus Autofluorescence (FAF)
Time frame: To week 52
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Study eye with diagnosis of GA of the macula secondary to AMD as described in the protocol 2. Total GA area in the study eye measuring between ≥2.5 mm\^2 and ≤17.5 mm\^2 as described in the protocol 3. BCVA of 55 letters or better using ETDRS charts (20/80 Snellen equivalent) in the study eye as described in the protocol 4. Sufficiently clear ocular media, adequate pupillary dilation and fixation to permit quality fundus imaging in the study eye as described in the protocol 5. Willing and able to comply with clinic visits and study-related procedures, including completion of the full series of meningococcal vaccinations and pneumococcal vaccination required per protocol Key
Exclusion criteria
- GA in either eye due to causes other than AMD, such as Stargardt disease, cone rod dystrophy or toxic maculopathies like hydroxychloroquine maculopathy 2. History or current evidence of Macular Neovascularization (MNV) and/or exudation or Peripapillary Choroidal N
Where
- Chandler, Arizona
- Phoenix, Arizona
- Scottsdale, Arizona
- Tucson, Arizona
- Springdale, Arkansas
- Beverly Hills, California
- Encino, California
- Fresno, California
- Fullerton, California
- Huntington Beach, California
- Irvine, California
- La Jolla, California
And 111 more locations — see the full list below.
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jul 9, 2026 · Source of record for eligibility and locations