LHON Treatment NR082 Granted Orphan Drug Designation


Recently, research and development (R&D) company Neurophth Therapeutics announced that the FDA granted Orphan Drug designation to its therapy NR082. Also known as rAAV2-ND4 or NFS-01 project, NR082 is designed to treat patients with Leber hereditary optic neuropathy (LHON). In particular, it treats patients with a specific ND4 gene mutation.

Orphan Drug Designation

Granted by the FDA, Orphan Drug designation is given to therapies which are being developed to diagnose, treat, or prevent rare diseases. These diseases are those which affect under 200,000 American citizens. Orphan Drug designation offers multiple benefits to drug developers, such as tax credits, 7 years of market exclusivity, grant funding, faster approval, and a waiver for fees associated with New Drug Applications (NDAs).


Over 200 gene mutations are associated with genetic retinal diseases. As a result, gene therapy represents an enormous opportunity for the future of genetic ophthalmologic disorders. LHON is considered one of the most common inherited retinal diseases, alongside retinitis pigmentosa and Stargardt disease. When researchers began looking into gene therapy for patients with these conditions, they discovered that adeno-associated viruses (AAVs) and lentivirus (LV) vectors, often used to deliver gene therapies, do not cause negative side effects. However, LUXTURNA is currently the only AAV gene therapy approved for use in patients with ophthalmologic conditions caused by RPE65 double allele mutations.

In terms of NR085, it expresses a functional ND4 gene, stimulating the reparation of optic neuropathy. First explored in 2011, NR085 shows sustained response and vision improvement over an 8-year period. Further, a clinical trial that took place from 2017 to 2018 also showed significant improvement. The trial enrolled 159 participants. After one year, 81 patients experienced significant vision improvement. Additionally, NR085 was shown to be safe and well-tolerated.

Next, Neurophth is looking to submit Investigational New Drug applications in both China and the United States.

Leber Hereditary Optic Neuropathy (LHON)

Caused by mitochondrial DNA gene mutations, Leber hereditary optic neuropathy (LHON) causes vision loss in both eyes. Generally, patients lose sight in one eye first. However, vision loss in the second eye usually occurs soon after. The condition is passed down maternally. However, men are 4-5x more likely to have LHON than females.

In many cases, symptom onset occurs in young adulthood. Most patients lose their vision completely by 40 years old. As vision loss occurs, patients may experience reduced color perception, blurred vision, and (in rare cases) peripheral neuropathy. The latter causes muscle weakness and nerve damage in the hands and feet. However, in most situations, LHON is relatively painless. As of right now, there are no effective treatment options for patients with LHON. Learn more about LHON here.

Jessica Lynn

Jessica Lynn

Jessica Lynn has an educational background in writing and marketing. She firmly believes in the power of writing in amplifying voices, and looks forward to doing so for the rare disease community.

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