title: Gene Therapy for Leber Hereditary Optic Neuropathy: Initial Results.
abstract: OBJECTIVE
  Leber hereditary optic neuropathy (LHON) is a disorder characterized by severe and rapidly progressive visual loss when caused by a mutation in the mitochondrial gene encoding NADH:ubiquinone oxidoreductase subunit 4 (ND4). We have initiated a gene therapy trial to determine the safety and tolerability of escalated doses of an adeno-associated virus vector (AAV) expressing a normal ND4 complementary DNA in patients with a G to A mutation at nucleotide 11778 of the mitochondrial genome.
  
  
  METHODS
  In this prospective open-label trial (NCT02161380), the study drug (self-complementary AAV [scAAV]2(Y444,500,730F)-P1ND4v2) was intravitreally injected unilaterally into the eyes of 5 blind participants with G11778A LHON. Four participants with visual loss for more than 12 months were treated. The fifth participant had visual loss for less than 12 months. The first 3 participants were treated at the low dose of vector (5 × 10(9) vg), and the fourth participant was treated at the medium dose (2.46 × 10(10) vg). The fifth participant with visual loss for less than 12 months received the low dose. Treated participants were followed for 90 to 180 days and underwent ocular and systemic safety assessments along with visual structure and function examinations.
  
  
  METHODS
  Five legally blind patients with G11778A LHON.
  
  
  METHODS
  Loss of visual acuity.
  
  
  RESULTS
  Visual acuity as measured by the Early Treatment Diabetic Retinopathy Study (ETDRS) eye chart remained unchanged from baseline to 3 months in the first 3 participants. For 2 participants with 90-day follow-up, acuity increased from hand movements to 7 letters in 1 and by 15 letters in 1, representing an improvement equivalent to 3 lines. No one lost vision, and no serious adverse events were observed. Minor adverse events included a transient increase of intraocular pressure (IOP), exposure keratitis, subconjunctival hemorrhage, a sore throat, and a transient increase in neutralizing antibodies (NAbs) against AAV2 in 1 participant. All blood samples were negative for vector DNA.
  
  
  CONCLUSIONS
  No serious safety problems were observed in the first 5 participants enrolled in this phase I trial of virus-based gene transfer in this mitochondrial disorder. Additional study follow-up of these and additional participants planned for the next 4 years is needed to confirm these preliminary observations.
authors.affiliation: Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida.
authors.forename: William J
authors.initials: WJ
authors.lastname: Feuer
authors.affiliation: Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida.
authors.forename: Joyce C
authors.initials: JC
authors.lastname: Schiffman
authors.affiliation: Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida.
authors.forename: Janet L
authors.initials: JL
authors.lastname: Davis
authors.affiliation: Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida.
authors.forename: Vittorio
authors.initials: V
authors.lastname: Porciatti
authors.affiliation: Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida.
authors.forename: Phillip
authors.initials: P
authors.lastname: Gonzalez
authors.affiliation: Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida.
authors.forename: Rajeshwari D
authors.initials: RD
authors.lastname: Koilkonda
authors.affiliation: Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida.
authors.forename: Huijun
authors.initials: H
authors.lastname: Yuan
authors.affiliation: Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida.
authors.forename: Anil
authors.initials: A
authors.lastname: Lalwani
authors.affiliation: Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida.
authors.forename: Byron L
authors.initials: BL
authors.lastname: Lam
authors.affiliation: Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida. Electronic address: JGuy@med.miami.edu.
authors.forename: John
authors.initials: J
authors.lastname: Guy
mesh_terms: D000328:Adult; D004272:DNA, Mitochondrial / Q000235:genetics*; D000229:Dependovirus / Q000235:genetics*; D004596:Electroretinography; D005260:Female; D015316:Genetic Therapy; D005822:Genetic Vectors; D006801:Humans; D058449:Intravitreal Injections; D008297:Male; D008875:Middle Aged; D009245:NADH Dehydrogenase / Q000235:genetics*; D029242:Optic Atrophy, Hereditary, Leber / Q000235:genetics / Q000503:physiopathology / Q000628:therapy*; D016133:Polymerase Chain Reaction; D020641:Polymorphism, Single Nucleotide; D011446:Prospective Studies; D041623:Tomography, Optical Coherence; D014792:Visual Acuity / Q000502:physiology; D058609:Visual Field Tests; D014794:Visual Fields
chemical_list: D004272:DNA, Mitochondrial; C098483:NADH dehydrogenase subunit 4; D009245:NADH Dehydrogenase