A Study to Evaluate the Safety, Tolerability, Pharmacokinetics, and Efficacy of RO7446603 Administered Alone or in Combination With Aflibercept or Faricimab in Participants With Diabetic Macular Edema

Inclusion Criteria:

• Documented diagnosis of diabetes mellitus (DM) (Type 1 or Type 2) with glycatedhemoglobin (HbA1c) < 12%

• Macular thickening secondary to DME involving the center of the fovea > 325 microns

• Decreased VA attributable primarily to DME between 25 and 73 ETDRS letters

Exclusion Criteria:

• Currently untreated DM or previously untreated participants who initiated oralanti-diabetic medication or insulin within 90 days prior to Day 1

• Uncontrolled blood pressure (BP)

• Pregnancy or breastfeeding, or intention to become pregnant during the study

• For Parts 1-4: IVT anti-VEGF treatment within 90 days prior to Day 1; For Part 5:IVT anti-VEGF treatment within 120 days prior to Day 1 or IVT anti-VEGF treatmentprior to Day 1 for treatment naïve participants

• Treatment with SUSVIMOTM (ranibizumab injection) prior to Day 1

• Any IVT or periocular (sub-tenons) corticosteroid treatment within 6 months prior toDay 1

• Any current or history of ocular disease other than DME that may confound assessmentof the macula or affect central vision

• Proliferative diabetic retinopathy (PDR) in the study eye

• Active or history of uveitis, vitritis (grade trace or above), and/or scleritis ineither eye Other protocol-specified inclusion/exclusion criteria may apply