GenSight's Gene Therapy Shows Better Outcomes When Administered During Dynamic Phase of LHON Disease
Key Insights
A new exploratory analysis published in Investigational Ophthalmology and Visual Science identifies key predictive factors for improved visual outcomes in LHON (search) patients treated with GenSight's gene therapy LUMEVOQ®.
Better baseline visual acuity and thicker retinal nerve fiber layer and ganglion cell layer measurements predict superior visual outcomes 1.5 years after treatment.
Patients treated during the dynamic phase of disease achieve better final visual outcomes than those treated during the subacute phase, challenging conventional treatment timing wisdom.
GenSight Biologics has announced the publication of groundbreaking research that identifies key predictive factors for visual recovery in patients with Leber hereditary optic neuropathy (search) (LHON (search)) treated with the company's investigational gene therapy LUMEVOQ® (lenadogene nolparvovec). The exploratory analysis, published in the July 2025 issue of Investigational Ophthalmology and Visual Science, reveals that treatment timing and baseline retinal structure measurements significantly influence therapeutic outcomes.
Key Predictive Factors Identified
The study concluded that "better baseline BCVA value and baseline thicker GCL (macular ganglion cell layer) and RNFL (retinal nerve fiber layer) are key predictors of the improved BCVA 1.5 years after treatment" among patients treated with LUMEVOQ® at least 6 months after disease onset. Researchers performed univariate analyses on 113 eyes of patients across three Phase III studies (RESCUE, REVERSE and REFLECT), examining best-corrected visual acuity (BCVA) at 1.5 years post-treatment as the primary outcome measure.
The analysis used age, gender, timing of treatment, baseline BCVA value and baseline optical coherence tomography (OCT) parameters as covariates. BCVA was assessed using the Early Treatment Diabetic Retinopathy Study (ETDRS) chart at 1 or 4 meters.
Dynamic Phase Treatment Shows Superior Outcomes
A particularly significant finding challenges conventional wisdom about optimal treatment timing. The analyses revealed that patients treated during the dynamic phase of the disease achieve better visual outcomes than patients treated during the subacute phase of the disease. The authors hypothesize that RNFL pseudoedema (swelling) during the subacute phase may hamper the diffusion of the viral vector to retinal ganglion cells (search) (RGCs (search)).
"In the dynamic phase of the disease, the stabilized retinal layers are sufficiently preserved to optimize the transfection efficiency of RGCs (search) and thus the effects of gene therapy," the researchers explained.
Clinical Implications and Recommendations
Dr. Robert C. Sergott, MD, lead author from the Departments of Ophthalmology and Neurology at Wills Eye Hospital and Thomas Jefferson University, emphasized the study's clinical significance. "The study is the first to use spectral domain-optical coherence tomography (SD-OCT) and other clinical outcomes to identify predictive factors of BCVA changes 1.5 years after treatment," noted Dr. Sergott, who also heads the Central Reading Center at William H. Annesley, Jr., EyeBrain Center.
The structural and functional evidence supports bilateral treatment approaches. "The structural and functional evidence concurs that direct injection of lenadogene nolparvovec may be more effective than the contralateral therapeutic effect, thus supporting a recommendation to treat LHON (search) patients bilaterally when possible," Dr. Sergott stated.
Study Design and Methodology
The research represents the first comprehensive analysis linking retinal structure with functional outcomes in LHON (search) gene therapy. Study authors noted that "by linking structure and function, improves our understanding of the factors influencing vision recovery after lenadogene nolparvovec administration in patients with MT-ND4 (search) LHON, showing that better baseline BCVA values and thicker baseline OCT retinal layers in the dynamic phase of the disease, particularly the outer segments of macular GCL, are the key predictive factors associated with better BCVA 1.5 years after treatment."
The findings demonstrate a clear relationship between preservation of retinal structures and treatment response. "This relationship between preservation of retinal structures and response to treatment strongly supports an effect of lenadogene nolparvovec on [retinal ganglion cell] RGC survival and function. These findings should facilitate optimization of patient selection for future clinical trials," the authors concluded.
Study Limitations and Future Directions
The researchers acknowledged several limitations, including the exploratory nature of the study and the absence of a pure sham/placebo control group. The inclusion of such a control group could provide insights on predictive factors of outcome in the spontaneous evolution of MT-ND4 (search) LHON (search) disease. Additionally, findings were limited to gene therapy administration during the subacute and dynamic phases of the disease.
About LHON and Current Treatment Landscape
Leber Hereditary Optic Neuropathy (search) is a rare maternally inherited mitochondrial genetic disease characterized by degeneration of retinal ganglion cells (search) that results in brutal and irreversible vision loss, mainly affecting adolescents and young adults. The disease is associated with painless, sudden loss of central vision in the first eye, with the second eye sequentially impaired. Ninety-seven percent of patients have bilateral involvement at less than one year of onset of vision loss, and in 25% of cases, vision loss occurs in both eyes simultaneously.