Efforts to develop gene therapies for hearing loss have been hampered by the lack of safe, efficient, and clinically relevant delivery modalities1,2. Here we demonstrate the safety and efficiency of Anc80L65, a rationally designed synthetic vector3, for transgene delivery to the mouse cochlea. Ex vivo transduction of mouse organotypic explants identified Anc80L65 from a set of other adeno-associated virus (AAV) vectors as a potent vector for the cochlear cell targets. Round window membrane injection resulted in highly efficient transduction of inner and outer hair cells in mice, a substantial improvement over conventional AAV vectors. Anc80L65 round window injection was well tolerated, as indicated by sensory cell function, hearing and vestibular function, and immunologic parameters. The ability of Anc80L65 to target outer hair cells at high rates, a requirement for restoration of complex auditory function, may enable future gene therapies for hearing and balance disorders.

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This work was supported by the Bertarelli Foundation grants (K.M.S., J.R.H.), the Jeff and Kimberly Barber Gene Therapy Research Fund (J.R.H.), the Patel Gene Therapy Fund (J.R.H.), Department of Defense Grant W81XWH-15-1-0472 (K.M.S.), the National Institutes of Health (NIH) 1R01DC015824 (K.M.S.), Nancy Sayles Day Foundation (K.M.S.), Lauer Tinnitus Research Center (K.M.S.), Giving/Grousbeck (L.H.V.), Foundation Fighting Blindness (L.H.V.), Ush2A Consortium (L.H.V.), and NIH 5DP1EY023177 (L.H.V.). The authors would like to thank H.-C. Lin and S. Narasimhan for help with the brain tissue staining protocol, G. Geleoc and C. Nist-Lund for assistance with vestibular tissue imaging, and R. Xiao, R. Shelke, Y. Lin, and T. Barungi for vector preparation.

Author information

Author notes

    • Charles Askew

    Present address: Gene Therapy Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.

    • Lukas D Landegger
    • , Bifeng Pan
    •  & Charles Askew

    These authors contributed equally to this work.

    • Konstantina M Stankovic
    • , Jeffrey R Holt
    •  & Luk H Vandenberghe

    These authors jointly directed this work.


  1. Eaton Peabody Laboratories, Department of Otolaryngology, Massachusetts Eye and Ear, Boston, Massachusetts, USA.

    • Lukas D Landegger
    •  & Konstantina M Stankovic
  2. Department of Otolaryngology, Harvard Medical School, Boston, Massachusetts, USA.

    • Lukas D Landegger
    • , Bifeng Pan
    • , Charles Askew
    • , Sarah D Gluck
    • , Konstantina M Stankovic
    •  & Jeffrey R Holt
  3. Department of Otolaryngology, Vienna General Hospital, Medical University of Vienna, Vienna, Austria.

    • Lukas D Landegger
  4. Department of Otolaryngology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, Massachusetts, USA.

    • Bifeng Pan
    • , Charles Askew
    • , Sarah D Gluck
    • , Alice Galvin
    •  & Jeffrey R Holt
  5. Grousbeck Gene Therapy Center, Schepens Eye Research Institute and Massachusetts Eye and Ear, Boston, Massachusetts, USA.

    • Sarah J Wassmer
    •  & Luk H Vandenberghe
  6. Ocular Genomics Institute, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA.

    • Sarah J Wassmer
    •  & Luk H Vandenberghe
  7. Harvard Program in Speech and Hearing Bioscience and Technology, Boston, Massachusetts, USA.

    • Sarah D Gluck
    •  & Konstantina M Stankovic
  8. Center for Auditory Research, UCL Ear Institute, London, UK.

    • Ruth Taylor
    •  & Andrew Forge
  9. Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts, USA.

    • Jeffrey R Holt
  10. Harvard Stem Cell Institute, Harvard University, Cambridge, Massachusetts, USA.

    • Luk H Vandenberghe


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L.D.L., B.P., C.A., S.J.W., S.D.G., and A.G. conducted, analyzed, and reported the mouse gene transfer experiments described, and R.T. and A.F. performed and led the human vestibular transduction experiments. L.H.V. provided vector materials. K.M.S., J.R.H., and L.H.V. conceived the study, led experimental design and oversaw analysis. J.R.H., L.H.V., and L.D.L. drafted the manuscript with topical input from all other authors.

Competing interests

L.H.V. holds founder equity in GenSight Biologics, is a consultant to a number of biotech and pharmaceutical companies, and is an inventor on gene therapy patents, including Anc80L65, which are licensed to various entities. L.H.V. also receives sponsored research from Lonza Houston and Selecta Biosciences, licensees of Anc80L65. L.H.V., K.M.S., and J.R.H. have filed a patent on the use of Anc80L65 in the cochlea.

Corresponding authors

Correspondence to Konstantina M Stankovic or Jeffrey R Holt or Luk H Vandenberghe.

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