# APBA Kısa Özet

A four-year observational follow-up of children previously enrolled in a phase II randomized trial of murine NGF eye drops found no significant changes in visual acuity, VEP amplitude, PhNR amplitude, or visual field radius from baseline. Brain MRI showed stable disease in all patients. The study concluded that short-term topical mNGF appears safe and well-tolerated with sustained stability, but not efficacy, and called for larger randomized trials to confirm clinical benefit.

# Çalışma neyi araştırdı?

This study evaluated long-term clinical and neuroradiological outcomes in children with optic pathway gliomas (OPG) who previously participated in a double-blind, randomized, placebo-controlled phase II trial of murine nerve growth factor (mNGF) eye drops. The original trial reported beneficial effects of short-term (10-day) mNGF treatment on visual function. The present study aimed to assess whether these benefits persisted or changed over a 48-month observational follow-up period.

# Yöntem

The study included 15 of the 18 patients originally enrolled in the phase II mNGF trial who agreed to undergo extended follow-up. Of these, 9 had been randomized to mNGF and 6 to placebo. No additional anti-tumor treatments were administered during the extended follow-up. Every 6 months, patients underwent comprehensive clinical and neuro-ophthalmological examinations, visual evoked potentials (VEP), photopic negative response (PhNR) of the electroretinogram, and brain MRI. The primary outcomes were changes in visual acuity, VEP amplitude, PhNR amplitude, and visual field radius from baseline. MRI assessments focused on disease stability.

# Temel bulgular

  • No statistically significant changes were observed in visual acuity, VEP amplitude, PhNR amplitude, or visual field radius from baseline values.
  • Brain MRI demonstrated stable disease in all 15 patients throughout the four-year observation period.
  • The median follow-up duration was 48 months.
  • No additional treatments (mNGF, chemotherapy, or radiotherapy) were administered during the follow-up period.

# Bulgular ne anlama geliyor?

These findings indicate that short-term topical murine NGF eye drops, originally administered in a phase II trial, are favorable in terms of long-term safety and tolerability. However, the study found no evidence of sustained clinical efficacy in preserving or improving visual function over four years. The sustained stability of both visual function and neuroradiological parameters suggests that the observed effects in the original trial were not maintained after treatment cessation, or that the short treatment course (10 days) does not alter the natural history of OPG-related visual decline.

# Klinik önem

The study authors concluded that further prospective, adequately powered and randomized clinical studies are needed to confirm both short- and long-term clinical efficacy of NGF treatment in preventing OPG-induced visual loss. In the interim, short-term topical mNGF can be considered a well-tolerated option with a favorable safety profile, but it should not be relied upon as a standalone treatment for visual preservation. Clinicians should manage patient and family expectations regarding the lack of demonstrated long-term benefit.

# Sınırlılıklar

  • Small sample size (n=15) limits generalizability of the findings.
  • Open-label observational design without a concurrent control group during the follow-up period.
  • No additional anti-tumor treatments were administered, which may not reflect real-world OPG management where chemotherapy or radiotherapy are often used.
  • Four-year follow-up may be insufficient to capture late-onset visual deterioration or long-term adverse effects.
  • Results may not be generalizable to other NGF formulations or different treatment regimens.
  • The original randomization was broken as all participants received open-label treatment in the follow-up phase.