Cenegermin for Neurotrophic Keratitis: Treating the Cause, Not Just the Surface

Candidate profile

The person this therapy is for has neurotrophic keratitis — a rare corneal disease in which the nerves supplying the cornea are damaged, leaving the eye's front surface numb and unable to heal itself. It commonly follows herpes simplex or shingles eye infections, diabetes, eye surgery, chemical burns, or long-term contact lens use. Depending on stage, patients may have a persistent, non-healing surface defect or, in severe cases, corneal ulceration that threatens sight.

A hallmark of the condition is a striking mismatch: the cornea can look badly damaged while the person feels little, precisely because the sensory nerves are impaired. That numbness is also why the disease is often caught late. This use case describes an approved therapy used under an ophthalmologist's care, not a self-directed remedy.

Why the mechanism fits

The root problem in neurotrophic keratitis is loss of the nerves' trophic (nourishing) support for the corneal surface. Nerve growth factor is the natural neurotrophin that corneal nerves and epithelial cells depend on. So rather than only lubricating or bandaging a failing surface, the targeted strategy is to restore NGF directly to the eye.

Cenegermin (Oxervate) is recombinant human NGF formulated as a preservative-free eye drop. By supplying NGF at the ocular surface, it supports the survival and function of corneal nerves and epithelial cells, promoting genuine healing and helping recover corneal sensation — addressing the neurodegenerative cause rather than only the symptoms.

The evidence

In randomized controlled trials (including the REPARO study in Europe and a subsequent US trial), an 8-week course of cenegermin significantly increased complete corneal healing in moderate-to-severe neurotrophic keratitis compared with vehicle drops, with healing maintained in many patients during follow-up. This evidence supported its approval as the first topical NGF therapy for the condition.

How it is used

• Regimen: one drop in the affected eye six times a day, roughly every two hours while awake, for eight weeks.
• Handling: it is preservative-free and requires specific cold storage and careful handling, which is part of why treatment is tightly supervised.
• A telling side effect: mild eye pain or discomfort on instillation is the most common effect — and partly reflects the drug working, as a previously numb cornea begins to regain sensation.

What it works alongside

Cenegermin is the targeted therapy, but it sits within broader ocular-surface care: intensive preservative-free lubrication to protect a vulnerable surface, treating any underlying infection or inflammation, stopping toxic topical medications, and, in advanced disease, measures like bandage contact lenses, autologous serum drops, amniotic membrane, or eyelid procedures. The underlying cause — poorly controlled diabetes, recurrent herpes eye disease — is managed in parallel.

Other peptides such as thymosin beta-4 have been studied for corneal healing, but they are investigational for this use; cenegermin is the approved, cause-directed option.

Honest limitations

• It is a prescription biologic managed by an ophthalmologist, not a wellness or research peptide, and not something to self-source.
• An 8-week course promotes healing but is not guaranteed to be permanent; outcomes vary and some cases need further treatment depending on the underlying nerve damage.
• It targets the neurotrophic cause but does not by itself resolve whatever originally injured the nerves, which must also be addressed.

The takeaway

Cenegermin is a rare example of a therapy that treats a corneal disease at its biological source — replacing the very nerve-support signal the eye has lost. Delivered as a demanding but well-defined 8-week eye-drop course under specialist care, it can restore healing to a cornea that could not heal on its own. It is a genuine, approved NGF peptide medicine, and its proper home is the ophthalmology clinic.

This article is educational and does not constitute medical advice. Neurotrophic keratitis is diagnosed and managed by an ophthalmologist.