An Open-label, Dose Escalation and Double-masked, Randomized, Controlled Trial Evaluating Safety and Tolerability of Sepofarsen in Children (<8 Years of Age) With LCA10 Caused by Mutations in the CEP290 Gene.

Inclusion Criteria:

• Male or female child, <8 years of age at Screening with a clinical diagnosis of LCAand a molecular diagnosis of homozygosity or compound heterozygosity for the CEP290p.Cys998X mutation, based on genotyping analysis at Screening. A historic genotypingreport from a certified laboratory are acceptable with Sponsor approval.
• BCVA equal to or better than Logarithm of the Minimum Angle of Resolution (logMAR) + 4.0 (Light Perception), and equal to or worse than logMAR + 0.4 in the treatment eye.
• Detectable outer nuclear layer (ONL) in the area of the macula.

Exclusion Criteria:

• Presence of any significant ocular or non-ocular disease/disorder which may put thesubject at risk because of participation in the trial' may influence the results ofthe trial, or the subject's ability to participate in the trial.
• Receipt within 1 month prior to Screening of any intraocular or periocular surgery (including refractive surgery), or an IVT injection or planned intraocular surgery orprocedure during the course of the trial.
• Current treatment or treatment within the past 12 months with therapies known toinfluence the immune system (including but not limited to cytostatics, interferons,TNF-binding proteins, drugs acting on immunophilins, or antibodies with known impacton the immune system).
• Current treatment or treatment within the past 3 months or planned treatment withdrugs known to be toxic to the lens, retina, or the optic nerve.
• Use of any investigational drug or device within 3 months or 5 half-lives of Day 1,whichever is longer, or plans to participate in another study of a drug or deviceduring the trial period.
• Any prior receipt of genetic or stem-cell therapy for ocular or non-ocular disease.