• Study demonstrates contralateral transfer of LUMEVOQ® after unilateral injection
  • Results suggest mechanistic explanation for bilateral improvement of visual function among ND4-LHON patients unilaterally treated with LUMEVOQ®

Paris, France, December 1, 2021, 7:30 am CET – GenSight Biologics (Euronext: SIGHT, ISIN: FR0013183985, PEA-PME eligible), a biopharma company focused on developing and commercializing innovative gene therapies for retinal neurodegenerative diseases and central nervous system disorders, today announced that the journal Molecular Therapy – Methods and Clinical Development has published the results of a mechanistic study demonstrating the transfer of LUMEVOQ® vector DNA from the injected eyes to the non-injected eyes of non-human primates.

The findings provide a mechanistic explanation for the bilateral improvement of best-corrected visual acuity (BCVA) observed in ND4-LHON patients unilaterally treated with a single intravitreal (IVT) injection of LUMEVOQ®, which was observed in all clinical trials of the gene therapy (unilaterally treated patients in REVEAL; RESCUE, REVERSE and RESTORE studies; and the unilaterally treated patients in the REFLECT study).1,2,3,4 

This work is consistent with our previous report published last year in Science Translational Medicine and by illuminating the unexpected bilateral effect, addresses some of the questions that arose when the contralateral effect was so consistently observed across the LUMEVOQ trials,” commented last and corresponding author José-Alain Sahel, MD, Co-founder of GenSight Biologics and of the Institut de la Vision (Sorbonne-Université/Inserm/CNRS), Paris, France, and Distinguished Professor and Chairman of the Department of Ophthalmology at the University of Pittsburgh School of Medicine, USA. “The implications for the design of future gene therapy trials are significant.”

Lead author David J. Calkins, PhD, O’Day Professor & Vice Chair and Director for Research at the Department of Ophthalmology and Visual Sciences at Vanderbilt University Medical Center, further noted, “Our study is a critical step towards understanding not only how bilateral improvement in vision occurs with unilateral gene therapy, but also mechanisms of interocular interactions more generally. Crosstalk  between the two optic projections could have ramifications for additional blinding eye diseases.”

In the LUMEVOQ® clinical studies, BCVA improved in both eyes of patients who received a unilateral injection of the gene therapy. The mechanism behind the contralateral therapeutic effect of LUMEVOQ® on untreated eyes was explored in a non-human primate (NHP) study that analyzed the biodistribution of LUMEVOQ® vector DNA (i.e., the therapeutic ND4 gene) in the visual system following a single unilateral IVT. Six monkeys received a single injection of LUMEVOQ® in their right eye at a dose equivalent to that used in humans. Three of these monkeys were monitored for 3 months and the other three for 6 months. Two control animals were monitored for 3 and 6 months but received a placebo injection.

As expected, LUMEVOQ® vector DNA was detected in all the eyes that were injected with the gene therapy. But vector DNA was also detected or quantified in the contralateral non-injected eyes for 5 of the 6 animals in the treatment group. In addition, vector DNA was detected or quantified in the optic chiasm of all 6 animals. The results provide evidence that LUMEVOQ® vector DNA reached the non-injected eye after unilateral IVT.

Because biodissemination studies have detected only a limited and transient presence of vector DNA in the blood of ND4-LHON patients treated with LUMEVOQ®, systemic transfer of vector DNA was ruled unlikely as the mechanism behind the results. The investigators instead consider transport via the optic nerve and chiasm along the anterior visual pathways as the likely mechanism for the transfer of the viral vector DNA to the untreated eye.

The authors also discuss other mechanisms that could participate in the contralateral treatment effect of LUMEVOQ®, such as the transfer of mitochondrial material (like RNA or proteins) between eyes and brain plasticity.

The paper is available at https://www.sciencedirect.com/science/article/pii/S2329050121001510. The article will be in the December 10 print issue of the journal.

*About the paper:

Biodistribution of Intravitreal Lenadogene Nolparvovec Gene Therapy in Nonhuman Primates


Authors: David J. Calkins,1 Patrick Yu-Wai-Man,2,3,4,5 Nancy J. Newman,6 Magali Taiel,7 Pramila Singh,8 Clémentine Chalmey,8 Alexandra Rogue,8 Valerio Carelli,9,10 Philippe Ancian,8 and José A. Sahel11,12,13,14



1Department of Ophthalmology and Visual Sciences, Vanderbilt University Medical Center, 1161 21st Avenue South, Nashville, TN 37232, USA

2Cambridge Centre for Brain Repair and MRC Mitochondrial Biology Unit, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK

3Cambridge Eye Unit, Addenbrooke’s Hospital, Cambridge University Hospitals, Cambridge, UK

4Moorfields Eye Hospital, London, UK

5UCL Institute of Ophthalmology, University College London, London, UK

6Departments of Ophthalmology, Neurology, and Neurological Surgery, Emory University School of Medicine, Atlanta, GA, USA

7GenSight Biologics, 74 rue du Faubourg Saint Antoine, 75012 Paris, France

8Charles River Laboratories, Evreux, France

9IRCCS Istituto delle Scienze Neurologiche di Bologna, UOC Clinica, Neurologica, Bologna, Italy;

10Unit of Neurology, Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy

11Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France

12Fondation Ophtalmologique A. de Rothschild, Paris, France

13Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA

14CHNO des Quinze-Vingts, Institut Hospitalo-Universitaire FOReSIGHT, INSERM-DGOS CIC, Paris, France



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  2. Newman NJ, Yu-Wai-Man P, Carelli V, Moster ML, Biousse V, Vignal-Clermont C, Sergott RC, Klopstock T, Sadun AA, Barboni P, DeBusk AA, Girmens JF, Rudolph G, Karanjia R, Taiel M, Blouin L, Smits G, Katz B, Sahel JA; LHON Study Group. Efficacy and Safety of Intravitreal Gene Therapy for Leber Hereditary Optic Neuropathy Treated within 6 Months of Disease Onset. Ophthalmology. 2021 May;128(5):649-660.
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  4. Biousse V, Newman NJ, Yu-Wai-Man P, Carelli V, Moster ML, Vignal-Clermont C, Klopstock T, Sadun AA, Sergott RC, Hage R, Esposti S, La Morgia C, Priglinger C, Karanja R, Blouin L, Taiel M, Sahel JA; LHON Study Group. Long-Term Follow-Up After Unilateral Intravitreal Gene Therapy for Leber Hereditary Optic Neuropathy: The RESTORE Study. J Neuroophthalmol. 2021 Sep 1;41(3):309-315. J Neuroophthalmol. 2021 Sep 1;41(3):309-315.