Recombinant human nerve growth factor (rhNGF) has shown promise as a treatment for dry eye disease in a phase I clinical trial.
“In this study, 4 weeks treatment with rhNGF eye drops at both 4 μg/mL and 20 μg/mL was effective in improving ocular surface damage and dry eye symptoms,” wrote Marta Sacchetti from the University of Sapienza of Rome in Rome, Italy and colleagues.
They published the finding in the British Journal of Ophthalmology.
The finding could lead to a much-needed new therapy for a disease that remains both common and difficult to treat, the researchers said.
Currently most treatments aim at either lubricating the exposed epithelia with tear substitutes or at controlling ocular surface inflammation with immunosuppressive drugs or steroids.
“Development of novel therapies targeting different pathogenic mechanisms is sought-after,” wrote the researchers.
Nerve growth factor (NGF), the first neurotrophin to be discovered, plays a key role in modulating the central and peripheral nervous, endocrine, immune and visual systems.
Preliminary clinical studies have shown that NGF drops from mice can safely and effectively treat neurotrophic keratitis and autoimmune corneal ulcers in humans. A novel recombinant human NGF produced in Escherichia coli (Cenergermin) received European Medicine Agency authorization in 2017 for these indications.
Other studies have suggested that NGF can improve ocular surface wound healing and sensitivity, and increase tear production and conjunctival goblet cell density.
To get a preliminary understanding of the safety and efficacy of rhNGF, Sacchetti and her colleagues enrolled divided 40 consecutive patients with moderate to severe non-Sjogren dry eye disease into 2 groups of 20. Both groups received rhNGF drops twice per day for 4 weeks.
One group received rhNGF in a concentration of 20 µg/mL. The other group received a concentration of 4 µg/mL. While both eyes were treated in all patients, results were only recorded for the more severe eye.