A Study Investigating Subcutaneously Administered Pozelimab in Combination With Cemdisiran or Cemdisiran Alone in Adult Participants With Geographic Atrophy

Key Inclusion Criteria: 1. 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: 1. 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 Neovascularization (PPCNV) in either eye as described in the protocol 3. Prior or current Intravitreal (IVT) treatment of any kind for any indication in study eye or fellow eye, except approved or investigational IVT complement inhibitor therapy or anti-VEGF therapy, as long as last dose was ≥6 months prior to randomization 4. Prior intraocular surgery except cataract extraction or minimally invasive glaucoma surgery in study eye as long as date of these procedures was ≥3 months prior to randomization 5. Comorbid progressive ocular condition (eg, diabetic retinopathy, macular edema, uncontrolled glaucoma, full thickness macular hole) in study eye that could affect central vision and confound study 6. Any ophthalmologic condition that reduces the clarity of the media and that, in the opinion of the investigator interferes with ophthalmologic examination of the study eye (e.g., advanced cataract or corneal abnormalities) as described in the protocol Systemic Exclusion criteria 7. History or current use of systemic complement inhibitor therapy within 6 months prior to randomization as described in the protocol 8. History of solid organ or bone marrow transplantation 9. Use of chronic (\>14 days) systemic corticosteroids (oral or parenteral, ≥20 mg oral prednisone or equivalent) within the previous 30 days prior to the first screening visit as described in the protocol 10. Current or prior use of systemic immunosuppressive therapy other than corticosteroids within 12 months prior to randomization or the likelihood of treatment with any such agent during the study inclusive of the screening period as described in the protocol 11. Not meeting meningococcal or pneumococcal vaccination requirements as described in the protocol 12. Carrier of Neisseria meningitidis based on culture collected during screening 13. Has a hemoglobin A1C ≥ 8.0% during screening as described in the protocol NOTE: Other protocol-defined Inclusion/ Exclusion Criteria apply