The latest clinical data continue to demonstrate the therapeutic potential of GenSight Biologics‘ lead candidate GS010 for the treatment of Leber’s Hereditary Optic Neuropathy (LHON), a rare mitochondrial disease. These data further support ongoing Phase 3 clinical trials.
GS010 is a gene therapy designed to deliver and promote the expression of the correct version of the mitochondrial gene ND4 in the eyes. The faulty version of this gene is the most common cause of LHON.
A Phase 1/2 trial (NCT02064569) is currently assessing the safety and tolerability of GS010 when administrated to LHON patients that carry the most common mutation associated with this disease, the G11778A mutation in the ND4 gene.
A total of 15 patients were treated with a single injection of GS010 in their worst-seeing eye. The patients were randomly distributed into five groups, each designed to receive escalating doses of the treatment.
Patients with shorter disease duration and better initial visual capabilities showed an overall positive response to treatment.
Those who had the disease for up to two years and a median visual acuity — baseline LogMAR acuity up to 2.79 —showed at week 78 post-injection a clinically meaningful improvement of 20 ETDRS Letters on the treated eye compared with the untreated eye. This result demonstrates the therapeutic potential of the investigative gene therapy to improve the visual acuity of LHON patients.
Overall, no systemic or serious adverse events related to the treatment were reported. The most common ocular adverse event was inflammation, which was mild in 13 of the participants. Only one patient developed severe ocular inflammation. The patients were treated with steroids, and all events progressed positively without any permanent consequences.
The findings were the subject of two poster presentations titled, “78-week follow-up study results after intravitreal rAAV2/2-ND4 (GS010) injection in patients with vision loss due to G11778A ND4 Leber Hereditary Optic Neuropathy,” and “Humoral and cellular immune responses to AAV2 and ocular inflammation in patients after intravitreal injection of rAAV2/2-ND4 (GS010), an investigational gene therapy for the treatment of ND4 LHON,” during the ESGCT congress.