GenSight Biologics 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). 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.