• To be eligible for study participation, subjects must meet the following criteria:

• Provide written consent. Subjects under legal age will also provide informed assent according to guidelines set forth by the same.

• Are male or female adolescents and adults, aged as follows:

∙ In Part A, subjects will be ≥18 to ≤65\* years (inclusive)

‣ In Part B, subject age is planned as ≥12 to ≤65\* years (inclusive) \*Subjects aged \>65 years may be eligible in Parts A and B, following discussion with, and approval by, the Medical Monitor.

• Are able to understand and comply with the study procedures.

• Have a diagnosis of STGD1 caused by bi-allelic pathogenic, or likely pathogenic, variants in the ABCA4 gene confirmed genotypically by an accredited genetic testing laboratory

• Clinical evidence consistent with Stargardt Disease type 1.

• For women of child-bearing potential (WOCBP), have a negative pregnancy test at Screening and, if due to receive active treatment, at Day 0.

• For both WOCBP and male subjects (or their female partners who are of child-bearing potential), agree to either strict abstinence or, if sexually active, use an acceptable contraception measure for 3 months from Day 0

• Must have clear ocular media and adequate pupillary dilation in the study eye, including no allergy to dilating eyedrops, to permit good quality retinal imaging.

• Fulfil visual acuity criteria based on ETDRS letter chart

⁃ Fulfil baseline lesion size measurement, as measured by the Reading Center

⁃ Evidence of disease progression as determined by the Medical Monitor following consultation with the Investigator.