Recombinant human nerve growth factor (cenegermin) for moderate-to-severe dry eye: phase II, randomized, vehicle-controlled, dose-ranging trial.

BACKGROUND: Dry eye disease (DED) includes neurosensory abnormalities as part of its multifactorial etiology. Nerve growth factor is important for maintaining corneal nerve integrity and wound healing. Cenegermin (recombinant human nerve growth factor) is a topical biologic that promotes corneal healing in patients with neurotrophic keratitis. The purpose of this study was to evaluate efficacy and safety of cenegermin in moderate-to-severe DED and identify an optimal dosing strategy. METHODS: This was a phase II, multicenter, randomized, double-masked, vehicle-controlled, dose-ranging clinical trial in patients with moderate-to-severe DED, including Sjögren's DED (NCT03982368). Patients received 1 drop of cenegermin 3 times daily (t.i.d.; 20 mcg/mL), cenegermin 2 times daily (b.i.d.; 20 mcg/mL) and vehicle once daily, or vehicle t.i.d. for 4 weeks. Follow-up continued for 12 additional weeks. The primary endpoint was change in Schirmer I score from baseline to week 4. Other key endpoints included rate of responders (Schirmer I test > 10 mm/5 min) after treatment and change in Symptoms Assessment iN Dry Eye (SANDE) scores from baseline to end of follow-up. A 1-sided test (α = 0.025) was used to evaluate statistical significance. RESULTS: At week 4, mean changes in Schirmer I scores were not statistically significantly different in either cenegermin group versus vehicle (cenegermin vs vehicle [treatment difference; 95% CI]: t.i.d., 2.60 mm and b.i.d., 3.99 mm vs 1.68 mm [t.i.d.: 0.93; -1.47 to 3.32, P = 0.078; b.i.d.: 2.31; -0.08 to 4.70, P = 0.066]). More patients responded to treatment with cenegermin t.i.d. and b.i.d. versus vehicle (t.i.d.: 25.9% [21/81, P = 0.028]; b.i.d.: 29.3% [24/82, P = 0.007] vs 11.9% [10/84]), with statistical significance (set at P < 0.025) observed in the b.i.d. group. Only cenegermin t.i.d. yielded statistically significant (P < 0.025) reductions in SANDE scores versus vehicle, which were sustained up to the end of follow-up (P value range, 0.002-0.008). Eye pain, primarily mild and transient, was the most frequently observed treatment-emergent adverse event with cenegermin. Similar results were observed in patients with Sjögren's DED. CONCLUSIONS: Cenegermin was well tolerated and although this study did not meet its primary endpoint, significant improvement in patient-reported symptoms of dry eye was observed through follow-up. Larger studies evaluating cenegermin in patients with DED are warranted. TRIAL REGISTRATION: NCT03982368; registered May 23, 2019.

The Role of Sensory Innervation in Homeostatic and Injury-Induced Corneal Epithelial Renewal.

The cornea is the window through which we see the world. Corneal clarity is required for vision, and blindness occurs when the cornea becomes opaque. The cornea is covered by unique transparent epithelial cells that serve as an outermost cellular barrier bordering between the cornea and the external environment. Corneal sensory nerves protect the cornea from injury by triggering tearing and blink reflexes, and are also thought to regulate corneal epithelial renewal via unknown mechanism(s). When protective corneal sensory innervation is absent due to infection, trauma, intracranial tumors, surgery, or congenital causes, permanent blindness results from repetitive epithelial microtraumas and failure to heal. The condition is termed neurotrophic keratopathy (NK), with an incidence of 5:10,000 people worldwide. In this report, we review the currently available therapeutic solutions for NK and discuss the progress in our understanding of how the sensory nerves induce corneal epithelial renewal.

Long-term clinical outcome and satisfaction survey in patients with neurotrophic keratopathy after treatment with cenegermin eye drops or amniotic membrane transplantation.

PURPOSE: Neurotrophic keratopathy (NK) is a degenerative corneal disease caused by damage of trigeminal innervation. The purpose of this study is to evaluate the clinical outcomes and patient-reported satisfaction of treatment with amniotic membrane transplantation (AMT) or cenegermin eye drops in patients with NK. METHODS: Clinical charts of patients with NK treated with AMT (group A) or cenegermin eye drops (group B), with at least 12 months of follow-up, were reviewed for demographics, medical history, corneal healing, and disease recurrence. Patient satisfaction was evaluated by a newly developed questionnaire investigating patient's appreciation of treatment of NK (2 items) and satisfaction with NK treatment outcomes (5 items). RESULTS: At the end of treatment, complete corneal healing was observed in 13/15 (86%) patients in group A and in 23/24 (96%) in group B. At 12 months follow-up, 6/13 patients (46%) in group A and 3/23 patients (13%) in group B showed recurrence of NK (p = 0.037). Survival analysis showed that group B remained recurrence free for a significantly longer period of time than the group A (p = 0.028). Patients in group B showed a significantly higher satisfaction when compared with patients in group A (total score: 65.7 ± 15.7 vs 47.4 ± 12.8, p = 0.003), both in terms of patients' appreciation of treatment (78.3 ± 15.9 vs 52.2 ± 30, p = 0.020) and satisfaction with treatment outcomes (60.7 ± 21 vs 45.4 ± 13.3, p = 0.037). CONCLUSIONS: Treatment of NK with cenegermin was associated with long-term maintenance of corneal integrity and a higher degree of patient satisfaction.

Ocular adverse events of cenegermin used in neurotrophic keratopathy: an analysis of the FDA adverse event reporting system database.

BACKGROUND: Cenegermin, a recombinant human nerve growth factor, is an orphan drug approved for neurotrophic keratitis. The safety information on the label is incomplete, and the adverse reactions noted are mostly mild and tolerable. However, the occurrence of painful epithelial plagues and irreversible corneal deposits after cenegermin usage have been reported. Real-world data on long-term ocular safety are lacking. We aimed to assess the cenegermin-associated eye safety profile in the FDA pharmacovigilance database. METHODS: The signals of cenegermin-related ocular adverse events (AEs) from 2018 to 2022 were quantified using the reporting odds ratio (ROR) and information component (IC). The grading system was used to prioritize the signals. RESULTS: We identified 3288 cases of cenegermin-related ocular AEs and 56 positive ocular-related signals. Fifty unexpected signals of ocular AE were identified. Eye ulcer was classified as a designated medical event. Twenty AEs, including corneal perforation, eye infection, corneal deposits, and eye inflammation, were recognized as important medical event. The median onset time for ocular AEs was 6 days (interquartile range [IQR]: 1-29 days). CONCLUSION: This study revealed new cenegermin-related ocular AE signals. Clinical practice requires close monitoring to early identify and manage adverse reactions that may cause occurrence of serious irreversible consequences.

The History of Nerve Growth Factor: From Molecule to Drug.

Nerve growth factor (NGF), the first neurotrophin to be discovered, has a long and eventful research journey with a series of turning points, setbacks, and achievements. Since the groundbreaking investigations led by Nobel Prize winner Rita Levi-Montalcini, advancements in the comprehension of NGF's functions have revolutionized the field of neuroscience, offering new insights and opportunities for therapeutic innovation. However, the clinical application of NGF has historically been hindered by challenges in determining appropriate dosing, administration strategies, and complications related to the production process. Recent advances in the production and scientific knowledge of recombinant NGF have enabled its clinical development, and in 2018, the United States Food and Drug Administration approved cenegermin-bkbj, a recombinant human NGF, for the treatment of all stages of neurotrophic keratitis. This review traces the evolutionary path that transformed NGF from a biological molecule into a novel therapy with potential research applications beyond the eye. Special emphasis is put on the studies that advanced NGF from discovery to the first medicinal product approved to treat a human disease.

Effect of Topical Recombinant Human Nerve Growth Factor on Corneal Epithelial Regeneration in Refractory Epithelial Keratopathy.

PURPOSE: To report the effect of topical application of recombinant human nerve growth factor (rhNGF) eye drops on corneal epithelial regeneration in patients with refractory epitheliopathy. METHODS: A retrospective chart review was conducted on patients treated with topical rhNGF for refractory epithelial keratopathy due to stage I neurotrophic keratitis (NK). Data regarding demographics and ocular/systemic past medical history was extracted from patient charts. Visual acuity and corneal staining scores were recorded at baseline and subsequent follow-up visits at 8 weeks and 3 months. Measurements from the worse eye were used to compare before and after treatment values. RESULTS: We identified 14 patients (median age 68 years, 21% male) who received rhNGF treatment for refractory epithelial keratopathy. After an 8-week treatment with topical rhNGF, the median corneal staining score in the worse eye improved from 4 to 1 (p = 0.001). All patients showed at least one-grade improvement in corneal staining at 8 weeks, with sustained effect in seven patients at 3 months. A better response was observed in eyes with post-radiation epithelial keratopathy, LASIK, and Sjogren's disease. Those with chronic use of other topical treatments and uncontrolled diabetes mellitus demonstrated incomplete responses. Eight patients reported mild-to-moderate ocular discomfort from drop application that fully resolved after completion of treatment. CONCLUSIONS: Topical rhNGF was effective and safe for refractory epithelial keratopathy in our small cohort, but sustained effects were seen only in certain etiologies for up to 3 months. Further studies are needed for optimal dosing and duration based on underlying causes.

The use of rh-NGF in the management of neurotrophic keratopathy.

Neurotrophic keratitis or keratopathy (NK) is a degenerative corneal disease induced by impairment of the trigeminal nerve function. This condition may lead to persistent epithelial defects, corneal ulceration, and perforation. The diagnosis of NK requires a careful investigation of any ocular and systemic condition associated with the disease and ocular surface and corneal sensitivity examinations. In the past, several medical and surgical procedures were used to treat this condition with different clinical effectiveness. Cenegermin is a recombinant human nerve growth factor (rh-NGF) that supports corneal reinnervation. Different clinical trials have demonstrated the safety and efficacy of topical cenegermin in patients with moderate to severe neurotrophic keratitis. In this review, we report the literature on clinical results regarding the treatment of NK with cenegermin since its approval by the European Medicines Agency (EMA) and the Food and Drug Administration (FDA) in 2017 and 2018, respectively.

Phase IV Multicenter, Prospective, Open-Label Clinical Trial of Cenegermin (rhNGF) for Stage 1 Neurotrophic Keratopathy (DEFENDO).

INTRODUCTION: Cenegermin is approved for treatment of neurotrophic keratopathy (NK) and has been studied in patients with stage 2 or 3 NK. This study evaluated the efficacy and safety of cenegermin in adults with stage 1 NK. METHODS: This was a phase IV, multicenter, prospective, open-label, uncontrolled trial. Adults with stage 1 NK (Mackie criteria) and decreased corneal sensitivity (≤ 4 cm) received 1 drop of cenegermin 20 mcg/ml in the affected eye(s) 6 times/day for 8 weeks with a 24-week follow-up. RESULTS: Of 37 patients, corneal epithelial healing was observed in 84.8% (95% confidence interval [CI] 68.1-94.9%; P < 0.001) at week 8; 95.2% (95% CI 76.2-99.9%; P < 0.001) of those patients remained healed at the end of the 24-week follow-up (week 32). At week 8, 91.2% (95% CI 76.3-98.1%; P < 0.001) of patients experienced improved corneal sensitivity; this improvement was observed in 82.1% (95% CI 63.1-93.9%; P < 0.001) of patients at week 32. Mean best-corrected distance visual acuity change from baseline at week 8 was - 0.10 logMAR (standard deviation [SD], 0.15; 95% CI - 0.16 to - 0.05; P < 0.001) and at week 32 was - 0.05 logMAR (SD, 0.16; 95% CI - 0.11 to 0.01; P = 0.122). At weeks 8 and 32, 15.2% (95% CI 5.1-31.9%; P < 0.001) and 10.7% (95% CI 2.3-28.2%; P < 0.001) of patients, respectively, had a 15-letter gain from baseline. At least one adverse event (AE) was reported by 73.0% and 45.7% of patients during the treatment and follow-up periods, respectively. The most common treatment-related, treatment-emergent AEs were eye pain (37.8%), blurred vision (10.8%), and eyelid pain (8.1%); these were mostly mild or moderate and were only reported during the treatment period. CONCLUSIONS: These results support the potential use of cenegermin for treating patients with stage 1 NK, and future confirmatory studies would be beneficial to elaborate on these findings. TRIAL REGISTRATION: DEFENDO; NCT04485546.

Can Nerve Growth Factor (NGF) Be a Treatment Option for Pediatric Eye Diseases?

A critical review of mechanisms of action and pharmacokinetics of nerve growth factor (NGF), including topical administration, and the studies showing the NGF treatment for anterior and posterior segment diseases in adult and pediatric population are summarized in our paper. Nerve growth factor is commonly used for many different ocular conditions in the adult population to promote nerve regeneration or cellular rescue. Clinical trials for recombinant human NGF have also treated several challenging ocular conditions, such as neurotrophic keratopathy, glaucoma, and retinitis pigmentosa with cystoid macular edema. The safety and efficacy of NGF have been demonstrated in pediatric patients as well. This leads us to consider new applications of NGF for the treatment of pediatric eye diseases.

Effect of recombinant human nerve growth factor treatment on corneal nerve regeneration in patients with neurotrophic keratopathy.

Introduction: Neurotrophic Keratopathy (NK) is a neurodegenerative corneal disease that results in diminished corneal sensation. Previous studies have found that Cenegermin 0.002%, a recombinant human nerve growth factor (rhNGF), improves corneal epithelial healing in stage 2 and 3 NK patients. However, rhNGF effect on corneal sensation and nerve regeneration has not been well established. Thus, this study aims to analyze the effect of rhNGF on corneal nerve regeneration using in vivo confocal microscopy (IVCM) and on corneal sensitivity in NK patients. Methods: This is a retrospective, longitudinal, case-control study that included patients with NK, treated with rhNGF for at least 4 weeks, with pre- and post-treatment IVCM images available for analysis. Chart reviews were conducted documenting prior medical and surgical history, clinical signs and symptoms, and corneal sensation using Cochet-Bonnet esthesiometry. Corneal nerve parameters were assessed by IVCM. Sex- and age-matched reference controls were selected from a database of healthy subjects for comparison. Results: The study included 25 patients, with 22 (88%) stage 1, two (8%) stage 2, and 1 (4%) stage 3 NK patients, with a median age of 64 years (range: 30-93 years). Total, main, and branch nerve densities [median (range) in mm/mm2] were lower in the NK group pre-treatment [2.3 (0.0-21.1); 1.7 (0.0-13.0); 0.5 (0.0-10.2); respectively] vs. controls [22.3 (14.9-29.0); 10.1 (3.2-15.4); and 12.1 (6.2-18.4), (p < 0.0001 for all), respectively]. Post-treatment nerve densities increased compared to pre-treatment to 5.3 (0.0-19.4, p = 0.0083) for total, 3.5 (0.0-13.2, p = 0.0059) for main, and 2.0 (0.0-10.4, p = 0.0251) for branch nerves, but remained lower than controls (p < 0.0001 for all). Corneal sensation increased from 2.3 ± 1.1 cm pre-treatment to 4.1 ± 1.4 cm post-treatment (p = 0.001). Median best corrected visual acuity significantly increased following rhNGF treatment from 0.4 (0.0-1.6) to 0.12 (-0.1 to 1.6) (p = 0.007). Conclusion: Patients with NK treated with at least 4 weeks of rhNGF, showed a significant increase in corneal nerve densities after treatment. A significant increase in corneal sensation, as well as best corrected visual acuity, was observed following treatment.

Cenegermin for the treatment of dry eye disease.

Dry eye disease (DED) is the most common ocular surface disorder affecting millions of people worldwide. Due to its chronic nature, the management of DED still represents a challenge in the ophthalmic practice. Nerve growth factor (NGF), which is expressed along with its high-affinity TrkA receptor on the ocular surface complex, has been widely studied for the treatment of neurotrophic keratopathy, and a novel recombinant human NGF (rhNGF) has recently received full market authorization in this setting. Since NGF has shown in both in vitro and in vivo studies to promote corneal healing, to enhance conjunctival epithelium differentiation and mucin secretion, and to stimulate tear film production and functionality, it could provide potential benefits also in patients with DED. A recent phase II clinical trial has assessed the role of rhNGF in DED patients, demonstrating significant improvements of DED signs and symptoms after 4 weeks of treatment. Further clinical evidence will be provided by the 2 ongoing phase III clinical trials. This review aims at comprehensively illustrating the rationale of use along with the efficacy and safety profile of topical NGF in patients with DED.

Topical cenegermin associated ocular surface and contact lens drug precipitate deposit formation.

Purpose: To report for the first time drug precipitate deposit formation on both the ocular surface and bandage contact lens (BCL) of a patient treated with topical cenegermin. Observations: A patient suffering from stage III neurotrophic keratitis developed extensive ocular surface and BCL deposits over the eight week course of her topical cenegermin therapy. The ocular surface deposits were weakly adherent, detaching and clearing from the cornea within minutes of BCL removal. They reappeared rapidly and repeatedly however after each of five BCL exchanges. Symptom wise, the patient was unaware of their presence. Of historical note, this patient: (1) developed BCL ciprofloxacin deposits while undergoing a traditional neurotrophic keratitis treatment regimen, (2) did not develop corneal drug precipitate deposits within the placebo arm of the cenegermin clinical trial (vehicle only without cenegermin or BCL), and (3) did not develop corneal deposits with a latter BCL-free cenegermin treatment course. Conclusions and Importance: Topical cenegermin can produce extensive drug precipitate deposits on both the ocular surface and contact lens when used in conjunction with a bandage contact lens. Such deposits: (1) may represent an esthetic issue only as at least in our patient they were not symptom provoking, questionably interfered with the clinical course of the cenegermin therapy and did not require drug cessation, (2) may implicate both contact lenses and high frequency drug application as previously unidentified but formal risk factors for drug precipitate deposit formation, and (3) may act as a time-release medication reservoir enhancing drug delivery and long-term treatment efficacy.

Observational study of cenegermin for the treatment of limbal stem cell deficiency associated with neurotrophic keratopathy.

Background: Neurotrophic keratopathy (NK) and limbal stem cell deficiency (LSCD) have high morbidity and require aggressive management to prevent permanent vision loss. Cenegermin, a recombinant human nerve growth factor, was approved by the Federal Drug Administration in 2018 for the treatment of NK. Objectives: To determine the efficacy and safety of cenegermin in the treatment of LSCD associated with NK. Design: Prospective cohort study. Methods: Patients diagnosed with LSCD and NK who had failed conventional treatment were enrolled in this prospective open-label study. Patients were treated with cenegermin for 8 weeks. The primary objective was to determine whether the area of abnormal epithelium decreased following treatment. Corneal sensation, visual acuity (VA), and LSCD severity were also evaluated. Results: Six eyes of 5 patients were included in the study. Cenegermin significantly improved the area of abnormal corneal epithelium in 5 of 6 eyes, measuring 73% of total corneal area at the initial visit and 48% at the final visit (P = .036). Corneal sensation improved in all patients, Cochet-Bonnet aesthesiometry measured 14.7 and 26.7 mm at the initial and final visit, respectively (P = .009). VA improved in 4 out of 6 eyes, with mean initial logMAR VA of 1.67 and final logMAR VA of 1.19 (P = .045). Finally, LSCD grading improved using the Aravena scoring system; however, this difference was not statistically significant (P = .14). One patient presented with an epithelial defect at baseline, which resolved following treatment. No patient withdrew from the study due to adverse effects. Conclusions: Cenegermin effectively improved the cornea epithelium, VA, and corneal sensation in patients with LSCD and NK who had failed prior treatment. Further studies are necessary to better understand the anatomical changes and to confirm our results with a larger randomized control trial. Registration: The study was registered at ClinicalTrials.gov with identifier NCT04552730 (https://clinicaltrials.gov/ct2/show/NCT04552730).

Neurotrophic keratopathy: Clinical presentation and effects of cenegermin.

Purpose: To report on 4 patients (3 adults, 1 child) with neurotrophic keratopathy (NK) treated with cenegermin 20 µg/ml (Oxervate®), a recombinant human nerve growth factor (rhNGF), which was authorized by the European Medicines Agency for the treatment of neurotrophic keratopathy stage 2 and stage 3 of Mackie Classification in patients over 18 years of age. Observations: Three patients with neurotrophic keratopathy stage 2 and 1 patient with neurotrophic keratopathy stage 3, who were treated with cenegermin eye drops 6 times daily for 8 weeks, were observed. Two patients suffered from herpetic keratitis and 2 patients from neurotrophic keratopathy secondary to orbital radiation. In addition to closure of epithelial defects, an increase of corneal sensitivity and improvement of visual acuity has been shown in all treated patients at the end of therapy. One patient reported on neuralgic pain as a side effect. The corneal epithelium remained closed during the follow-up period of 11 weeks, 31 and 32 months after cessation of therapy in 3 patients, respectively. In one patient, corneal erosion recurred 4 weeks after completion of treatment due to recurrent HSV keratitis, which resolved after therapy adjustment and the corneal epithelium remained closed for 35 weeks. Conclusion: The cases presented suggest that treatment with cenegermin 20 µg/ml not only promotes corneal epithelial wound healing, but also significantly improves corneal sensitivity and visual acuity with minor side effects in adults and children.

Neurotrophic Keratopathy Treated with Topical Recombinant Human Nerve Growth Factor (Cenegermin): Case Series Study with Long-Term Follow-Up.

The authors report the use of topical recombinant human nerve growth factor cenegermin 0.02% in 5 patients diagnosed with neurotrophic keratopathy (NK) in a real-life setting. These 5 patients affected with stage II and III NK mainly of herpetic cause received cenegermin six times daily for 8 weeks. It was initiated upon refractoriness to prior conventional topical treatment. Visual acuity, corneal sensitivity test at four corneal quadrants, fluorescein staining, OC,T and photography were performed weekly during 9 weeks of follow-up from the completion of treatment. At the ninth week of follow-up, corneal sensitivity improvement and healing of corneal ulcers were found in all patients. No adverse events were reported, and no corneal ulcer recurrence was observed over a 4-year follow-up period. Cenegermin should be used in combination with conventional therapy for advanced NK, as it is an effective treatment for healing corneal ulcers, improving the corneal surface homeostasis and avoiding surgery.

Neurotrophic Keratopathy in Systemic Diseases: A Case Series on Patients Treated With rh-NGF.

Purpose: To evaluate the prevalence, clinical ocular presentation and corneal healing in moderate and severe neurotrophic keratopathy (NK) caused by systemic diseases and treated with rh-NGF. Setting: Department of Biomedical and Dental Sciences and Morphofunctional Imaging, Ophthalmology Clinic, University of Messina, Italy. Design: Retrospective observational study of case series. Materials and Methods: In this retrospective observational study 11 patients (five female and six males) aged from 24 to 88 years (55.4 ± 21.3 years) with moderate and severe NK caused by systemic diseases were enrolled. The VAS questionnaire was dispensed. The ocular examination comprised slit lamp evaluation, ocular surface assessment with Keratograph 5M (Oculus, Germany), corneal sensitivity with Cochet-Bonnet esthesiometer (Lunneaux, France) and corneal thickness measurement with AC-OCT (DRI, Triton, Topcon, Japan). The underlying systemic causes of NK were determined. Results: The main cause of NK was post-neuroma surgery (36%), followed by diabetes (18%). The remaining causes were rheumatoid arthritis (9%), post-traumatic (9%), post-surgery (9%), atopia (9%), Graves' disease (9%). Seven eyes presented severe grade of NK with corneal ulcer and in four a moderate grade was registered. The rh-NGF (Cenegermin) was administered with a standard protocol one drop six times daily for 8 weeks. The complete healing of all corneal defects was registered at the end of the treatment. Conclusions: The post-neuroma surgery was the most common cause of NK and severe grade was clinically more represented. The rh-NGF proved effective to promote corneal recovery with all defects healed after the treatment.

Topical human recombinant nerve growth factor for stage 1 Neurotrophic Keratitis: Retrospective case series of cenegermin treatment.

Purpose: To report on the management and effectiveness of treating patients with stage I Neurotrophic Keratitis using an 8-week course of topical recombinant human nerve growth factor (rhNGF, cenegermin). Observations: In this retrospective case series, punctate epithelial erosions (PEE), best corrected visual acuity (BCVA) and corneal sensation were followed and documented from 2 to 12 months in patients treated as per the standard of care. Clinical outcomes including changes in PEEs, corneal sensation and BCVA are reported. Most patients also had preexisting thyroid disease. Conclusions: All patients had clinically significant improvements in PEE, and corneal sensation. Three of the four patients had a significant improvement in BCVA, one patient had no change in their pre-treatment visual acuity (BCVA 20/20) The four patients studied also reported decreased photophobia and improvements in their quality of life. This case series provides real-world evidence of the safety and efficacy of cenegermin treatment of stage I NK for all four patients.

Eight months follow-up of corneal nerves and sensitivity after treatment with cenegermin for neurotrophic keratopathy.

BACKGROUD: Cenegermin (Oxervate, Dompè Farmaceutici, Milan, IT), a recombinant human NGF, is a potentially healing new drug for neurotrophic keratopathy (NK), a rare but challenging disease affecting the cornea. To date, studies that evaluate its mid-term effect on corneal nerves and sensitivity are lacking. OBJECTIVE: To evaluate the recovery and morphology of subbasal corneal nerves in patients treated with Cenegermin for NK and assess their correlation with corneal sensitivity. METHODS: This prospective, observational case series study was carried out between May 2018 and August 2020 at the Ophthalmic Clinic of the University of Verona. Clinical evaluation, sensitivity, and in vivo confocal microscopy (IVCM) were performed in the central and all four corneal sectors at baseline, the end of therapy (8 weeks), and 2, 4, and 8 months after therapy. Consecutive patients with NK (stage 2-3), treated with Cenegermin (1 drop 6 times daily for 8 weeks), were enrolled. During each visit, Corneal nerve fiber length (CNFL), corneal nerve fiber total branch density (CTBD), corneal nerve fiber fractal dimension (CNFraD) and Cochet-Bonnet esthesiometry (CBE) were measured. RESULTS: We enrolled 18 patients. Complete NK healing was noted in 14/18(78%) patients after 8 weeks of treatment; then in 14(78%), 15(83%), and 13(72%) patients at 2-, 4-, and 8-months, respectively. Starting at 8 weeks through 4-month follow-up there was progressive improvement in CBE in all corneal sectors (p ≤ 0.01), which continued thereafter. There was significant corneal nerve regrowth especially in the peripheral cornea: centripetal progression starting at 8 weeks (CNFL and CNFrad) and significant branching starting at 2 months (CTBD), which continued through to the end of follow up. Sector-coupled IVCM and CBE findings correlated at all evaluations (all r ≥ 0.62 starting at 2 months, with highest values in the peripheral sectors). CONCLUSIONS: After Cenegermin we observed a subbasal corneal nerve regeneration, a recovery of sensitivity and a lasting epithelial healing, suggesting that the effect of its action persists several months after discontinuation in patients with NK.

Long-term clinical efficacy of topical treatment with recombinant human nerve growth factor in neurotrophic keratopathy: a novel cure for a rare degenerative corneal disease?

BACKGROUND: Neurotrophic keratopathy (NK) is a rare, degenerative ocular disease characterized by reduction or loss of corneal sensitivity and development of non-healing corneal epithelial defects and ulcers. Cenegermin, a recombinant human nerve growth factor (rhNGF) eye drop solution, is the first drug approved for the treatment of NK. The aim of our study is to evaluate the long-term efficacy of this innovative topical treatment in patients with NK. METHODS: Retrospective, consecutive, observational case series study from a single-center setting (Department of Sense Organs, University Sapienza of Rome, Rome, Italy). 18 patients with diagnosis of stage 2 or 3 NK, treated with Cenegermin 20 mcg/ml eye drops were followed for up to 48 months. Recurrence of lesion during follow-up was evaluated at 12, 24, 36, and 48 months. In addition, corneal sensitivity, Schirmer tear test, and visual acuity (VA) were recorded at baseline, end of treatment, and at 12, 24, 36, and 48 months. RESULTS: Three patients experienced recurrence of persistent epithelial defects (PEDs) within 12 months and one patient experienced recurrence of a corneal ulcer within 36 months. Corneal sensitivity was significantly improved at all timepoints (P < 0.05). Significant improvements in visual acuity and tear production were seen at the completion of treatment as well as at 12, 24, and 36 months (P < 0.05) when compared to baseline. CONCLUSIONS: A single 8-week treatment regimen of Cenegermin eye drops has clinical efficacy that can persist for up to 48 months. The long-term clinical utility of treatment with Cenegermin for NK was demonstrated through the low rate of lesion recurrence along with improvements in corneal sensitivity and tear production.