The final results from the REFLECT phase 3 clinical trial have provided crucial insights into the optimal administration strategy for gene therapy in Leber Hereditary Optic Neuropathy (LHON). The study confirms that bilateral treatment with the gene therapy lenadogene nolparvovec (Lumevoq) results in a greater proportion of patients experiencing meaningful visual recovery compared to unilateral treatment.
Lenadogene nolparvovec is an investigational gene therapy targeting the MT-ND4 mutation, the most prevalent cause of LHON. The REFLECT trial enrolled 98 patients, all of whom received an intravitreal injection of the therapy in their first affected eye. The second eye was then randomized to receive either a second injection of the gene therapy or a placebo, allowing researchers to directly compare unilateral versus bilateral treatment.
The five-year data, presented by researchers from the University of Cambridge, revealed that 75% of patients who received bilateral treatment achieved clinically relevant visual recovery. In contrast, 60% of those treated unilaterally reached the same milestone. Furthermore, 79% of bilaterally treated patients were able to read letters on a vision chart, compared to 72% in the unilateral group.
These findings are significant as they suggest that while unilateral treatment provides a bilateral benefit—likely due to the transfer of the viral vector between eyes via the optic chiasm—direct bilateral administration maximizes the therapeutic effect. The safety profile remained consistent across both groups, with intraocular inflammation being the most common, yet manageable, adverse event.
The REFLECT trial's results strongly support the potential of lenadogene nolparvovec as a long-term treatment for LHON and highlight the enhanced efficacy of treating both eyes. This data will be instrumental in guiding future clinical practices and regulatory decisions regarding gene therapy for mitochondrial optic neuropathies.
Medical Disclaimer: This information is for educational purposes only and does not constitute medical advice. Genetic testing and clinical management should be performed by qualified healthcare professionals.