Efficacy and Safety of AAV2-REP1 for the Treatment of Choroideremia

This is a phase 3 clinical trial of a gene therapy vector made from adeno-associated virus
(AAV) called AAV2-REP1 for the treatment of Choroideremia. Participating subjects will be
required to attend a screening visit during which their suitability for the study will be
assessed, and eligible subjects will be randomized to either AAV2-REP1 treatment or the
control group.

Inclusion Criteria:

- Are willing and able to give informed consent for participation in the study.

- Are male and ≥18 years of age.

- Have a genetically-confirmed diagnosis of CHM.

- Have active disease clinically visible within the macular region in the study eye.

- Fulfill pre-defined visual acuity criteria.

Exclusion Criteria:

- Have a history of amblyopia in the eligible eye.

- Are unwilling to use barrier contraception methods, for a period of 3 months, if
treated with AAV2-REP1.

- Previous intraocular surgery performed in the study eye within 3 months of Visit 1.

- Have any other significant ocular or non-ocular disease/disorder which, in the opinion
of the investigator, may either put the subjects at risk because of participation in
the study, or may influence the results of the study, or the subject's ability to
participate in the study.

- Have participated in another research study involving an investigational product in
the past 12 weeks or received a gene/cell-based therapy at any time previously.