4D-150 in Patients With Diabetic Macular Edema

Inclusion Criteria:

• ≥18 years of age

• Type I or Type II diabetes mellitus with macular thickening secondary to DMEinvolving the center of the fovea; diagnosis of DME must be within 2 years ofScreening

• CST ≥ 350 μm (Spectralis SD-OCT) in the study eye at Screening, confirmed by theindependent reading center

• Demonstrate clinical response to on-study aflibercept injection in the study eye.

• Decreased visual acuity attributable primarily to DME

• BCVA in the study eye between 25 and 83 ETDRS letters, inclusive (~20/320 and 20/25,respectively) at Screening

• Study eye amenable to IVT injection

• Sufficient clear ocular media, pupil dilation and fixation in the study eye topermit adequate imaging; ability to perform tests of visual and retinal function andstructure; and ability to comply with other protocol-specified procedures

• Provide written informed consent

Exclusion Criteria:

• Macular edema in the study eye considered to be secondary to a cause other than DME

• Systemic anti-VEGF treatment (e.g. sunitinib, bevacizumab, pazopanib) within 6months, or anticipated need for systemic anti-VEGF therapy during studyparticipation

• Systemic corticosteroids (oral, intravenous, intramuscular, intra-articular) orother immunosuppressive medications within 3 months

• Received an investigational drug, agent, device, or therapy (ocular or non-ocular)in the 3 months (or at least 5 half-lives, whichever is longer) prior to 4D-150administration (Day 1)

• Prior gene therapy (ocular or non-ocular) and/or ocular stem cell therapy in eithereye

• Any concurrent ocular condition in the study eye that is likely to require surgicalintervention (e.g. cataract surgery) during the 2 year (104 week) study duration

Note: Other inclusion/exclusion criteria apply.