RESUMEN
BACKGROUND: Gene therapy has the potential to reverse disease or prevent further deterioration of vision in patients with incurable inherited retinal degeneration. We therefore did a phase 1 trial to assess the effect of gene therapy on retinal and visual function in children and adults with Leber's congenital amaurosis. METHODS: We assessed the retinal and visual function in 12 patients (aged 8-44 years) with RPE65-associated Leber's congenital amaurosis given one subretinal injection of adeno-associated virus (AAV) containing a gene encoding a protein needed for the isomerohydrolase activity of the retinal pigment epithelium (AAV2-hRPE65v2) in the worst eye at low (1.5 x 10(10) vector genomes), medium (4.8 x 10(10) vector genomes), or high dose (1.5 x 10(11) vector genomes) for up to 2 years. FINDINGS: AAV2-hRPE65v2 was well tolerated and all patients showed sustained improvement in subjective and objective measurements of vision (ie, dark adaptometry, pupillometry, electroretinography, nystagmus, and ambulatory behaviour). Patients had at least a 2 log unit increase in pupillary light responses, and an 8-year-old child had nearly the same level of light sensitivity as that in age-matched normal-sighted individuals. The greatest improvement was noted in children, all of whom gained ambulatory vision. The study is registered with ClinicalTrials.gov, number NCT00516477. INTERPRETATION: The safety, extent, and stability of improvement in vision in all patients support the use of AAV-mediated gene therapy for treatment of inherited retinal diseases, with early intervention resulting in the best potential gain. FUNDING: Center for Cellular and Molecular Therapeutics at the Children's Hospital of Philadelphia, Foundation Fighting Blindness, Telethon, Research to Prevent Blindness, F M Kirby Foundation, Mackall Foundation Trust, Regione Campania Convenzione, European Union, Associazione Italiana Amaurosi Congenita di Leber, Fund for Scientific Research, Fund for Research in Ophthalmology, and National Center for Research Resources.
Asunto(s)
Proteínas Portadoras/genética , Proteínas del Ojo/genética , Terapia Genética/métodos , Atrofia Óptica Hereditaria de Leber/terapia , Adolescente , Adulto , Factores de Edad , Ceguera/congénito , Ceguera/genética , Niño , Adaptación a la Oscuridad , Dependovirus/genética , Progresión de la Enfermedad , Relación Dosis-Respuesta a Droga , Electrorretinografía , Femenino , Vectores Genéticos/genética , Vectores Genéticos/uso terapéutico , Humanos , Inyecciones , Masculino , Mutación/genética , Nistagmo Fisiológico , Atrofia Óptica Hereditaria de Leber/diagnóstico , Atrofia Óptica Hereditaria de Leber/genética , Seguridad , Resultado del Tratamiento , Agudeza Visual , Adulto Joven , cis-trans-IsomerasasRESUMEN
Leber's congenital amaurosis (LCA) is a group of inherited blinding diseases with onset during childhood. One form of the disease, LCA2, is caused by mutations in the retinal pigment epithelium-specific 65-kDa protein gene (RPE65). We investigated the safety of subretinal delivery of a recombinant adeno-associated virus (AAV) carrying RPE65 complementary DNA (cDNA) (ClinicalTrials.gov number, NCT00516477 [ClinicalTrials.gov]). Three patients with LCA2 had an acceptable local and systemic adverse-event profile after delivery of AAV2.hRPE65v2. Each patient had a modest improvement in measures of retinal function on subjective tests of visual acuity. In one patient, an asymptomatic macular hole developed, and although the occurrence was considered to be an adverse event, the patient had some return of retinal function. Although the follow-up was very short and normal vision was not achieved, this study provides the basis for further gene therapy studies in patients with LCA.
Asunto(s)
Ceguera/terapia , Proteínas Portadoras/genética , Proteínas del Ojo/genética , Terapia Genética , Vectores Genéticos , Degeneración Retiniana/terapia , Adulto , Ceguera/congénito , Ceguera/genética , Ceguera/patología , ADN Complementario , Dependovirus/genética , Técnicas de Transferencia de Gen , Humanos , Inyecciones , Mutación , Regiones Promotoras Genéticas , Reflejo Pupilar , Retina/patología , Degeneración Retiniana/congénito , Degeneración Retiniana/genética , Degeneración Retiniana/patología , Agudeza Visual , cis-trans-IsomerasasRESUMEN
The short- and long-term effects of gene therapy using AAV-mediated RPE65 transfer to canine retinal pigment epithelium were investigated in dogs affected with disease caused by RPE65 deficiency. Results with AAV 2/2, 2/1, and 2/5 vector pseudotypes, human or canine RPE65 cDNA, and constitutive or tissue-specific promoters were similar. Subretinally administered vectors restored retinal function in 23 of 26 eyes, but intravitreal injections consistently did not. Photoreceptoral and postreceptoral function in both rod and cone systems improved with therapy. In dogs followed electroretinographically for 3 years, responses remained stable. Biochemical analysis of retinal retinoids indicates that mutant dogs have no detectable 11-cis-retinal, but markedly elevated retinyl esters. Subretinal AAV-RPE65 treatment resulted in detectable 11-cis-retinal expression, limited to treated areas. RPE65 protein expression was limited to retinal pigment epithelium of treated areas. Subretinal AAV-RPE65 vector is well tolerated and does not elicit high antibody levels to the vector or the protein in ocular fluids or serum. In long-term studies, wild-type cDNA is expressed only in target cells. Successful, stable restoration of rod and cone photoreceptor function in these dogs has important implications for treatment of human patients affected with Leber congenital amaurosis caused by RPE65 mutations.