GS010 is an AAV2 gene therapy vector that encodes the human wild-type ND4 protein, which we are developing as a treatment of LHON caused by mutation of the ND4 gene.
The ND4 gene is normally located in the mitochondria where ND4 proteins are synthesized. GS010 allows efficient allotopic expression of the mitochondrial gene ND4 in the nucleus thanks to a proprietary Mitochondrial Targeting Sequence that shuttles the messenger RNA from the nucleus directly to the outer membrane of the mitochondria. There, the ND4 proteins are synthesized and incorporated into the mitochondria. Wild-type ND4 proteins then integrate into Complex I of the respiratory chain and rescue the deficiency.
We believe that GS010 can become the first curative treatment for LHON, thereby addressing a significant unmet medical need in this rare disease.
Trials with enrollment already closed
A Phase I/II trial, completed in France subjects with long-standing vision loss from LHON with the ND4 gene mutation, demonstrated that GS010 was well-tolerated. Two Phase 3 trials (RESCUE and REVERSE), to evaluate the efficacy of GS010 in LHON patients with a recent onset of disease (i.e., less than one year), were completed in 2019 in Europe and the US. We reported full Week 48 results from REVERSE in June 2018 and Week 48 results from RESCUE in 2019. Results of follow-up visits up to Week 96 in both trials were reported in 2019. Patients in both trials were invited to participate in a long-term follow-up study, which will monitor safety and efficacy up to 5 years after injection.
Studies being initiated
Two additional studies have been initiated. The first, a clinical trial pursuant to a special protocol assessment with the FDA, is the REFLECT study, which will evaluate the efficacy and safety of bilateral intravitreal injection of GS010 for the treatment of vision loss up to 1 year. The second is the REALITY LHON Registry retrospective study to understand the evolution of visual functions and structural changes and other associated symptoms in patients with LHON.
Expanded access / compassionate use
In some circumstances, a patient may not be able to participate in a clinical trial. Seeking use of an investigational medication under these circumstances is permitted by the FDA and commonly referred to as compassionate use or expanded access. Our policy is intended to comply with U.S. Food and Drug Administration (FDA) requirements for any such use or access. Please see the attached document for details.