Study to Evaluate QR-110 in Subjects With Leber's Congenital Amaurosis (LCA) Due to the c.2991+1655A>G Mutation (p.Cys998X) in the CEP290 Gene

The purpose of this study is to evaluate the safety and tolerability of QR-110 administered
via intravitreal injection in subjects with LCA due to the CEP290 p.Cys998X mutation.
Subjects will receive QR-110 in one eye every 3 months, for a maximum of 4 doses. Up to 3
dose levels of QR-110 will be evaluated.

Inclusion Criteria:

- Male or female, ≥ 6 years of age at Screening with a clinical diagnosis of LCA and a
molecular diagnosis of homozygosity or compound heterozygosity for the CEP290
p.Cys998X mutation.

- Best-corrected visual acuity greater than or equal to light perception in both eyes
and equal to or worse than LogMAR +1.0 (Snellen notation 20/200) in the worse eye and
equal to or worse than LogMAR +0.7 (Snellen notation 20/100) in the contralateral eye.

- Detectable outer nuclear layer (ONL) in the area of the macula.

- An electroretinogram (ERG) result consistent with LCA.

- Clear ocular media and adequate pupillary dilation to permit good quality retinal
imaging.

Exclusion Criteria:

- Syndromic disease.

- Pregnant or breast-feeding female.

- Any clinically significant cardiac disease or defect.

- One or more coagulation parameters outside of the normal range.

- Any ocular disease or condition that could compromise treatment safety, visual acuity
or interfere with assessment of efficacy and safety.

- Prior receipt of intraocular surgery or intravitreal injection within 3 months prior
to study start or planned intraocular surgery or procedure during the course of the
study.

- Use of any investigational drug or device within 90 days or 5 half-lives of Day 1,
whichever is longer, or plans to participate in another study of a drug or device
during the PQ-110-001 study period.

- Any prior receipt of genetic therapy for LCA