NCT02939937

Effect of Phenytoin on the Ganglion Cell Layer in Patients With Optic Neuritis

Completed Phase 2 Results posted Last updated 12 August 2019

What this trial tests

Phase 2 trial testing Phenytoin in Optic Neuritis in 71 participants. Completed in 2 January 2019.

Timeline

9 March 2017

Primary endpoint
11 November 2018

2 January 2019

Quick facts

Lead sponsor	Tehran University of Medical Sciences
Phase	Phase 2
Status	Completed
Study type	INTERVENTIONAL
Allocation	non randomized
Design	parallel
Masking	quadruple
Primary purpose	treatment
Enrollment	71
Start date	9 March 2017
Primary completion	11 November 2018
Estimated completion	2 January 2019
Sites	1 location across Iran

Drugs / interventions tested

• Phenytoin (PHENYTOIN) — full drug profile →
• placebo

Conditions studied

• Optic Neuritis — all drugs for Optic Neuritis →

Sponsor

Tehran University of Medical Sciences

Who can join

Adults 18 to 60, any sex, with Optic Neuritis. Patients with the condition only — healthy volunteers not accepted.

Results — posted to ClinicalTrials.gov

Per-arm endpoint measurements with 95% confidence intervals where reported. Source: trial results section.

Retinal Ganglion Cell Inner Plexiform Layer Thickness Primary · Measured at baseline and month 1, 6

ganglion cell inner plexiform layer thickness measure in 8 sectors by Heidelberg spectral-domain Optical Coherence Tomography

baseline

Group	Value	95% CI
Phenytoin	36.56	± 6.61
Placebo	34.65	± 8.49

1 month

Group	Value	95% CI
Phenytoin	31	± 6.61
Placebo	29.42	± 5.98

6 months

Group	Value	95% CI
Phenytoin	30.70	± 5.56
Placebo	32.12	± 9.10

Macular Layer Thickness Primary · Measured at baseline and month 1, 6

macular layer thickness measure in 8 sectors by Heidelberg spectral domain Optical Coherence Tomography

baseline

Group	Value	95% CI
Phenytoin	262.73	± 22.02
Placebo	265.98	± 22.5

1 month

Group	Value	95% CI
Phenytoin	255	± 19.72
Placebo	264.39	± 22.53

6 months

Group	Value	95% CI
Phenytoin	269	± 28.29
Placebo	268.37	± 22.69

Best Corrected Visual Acuity Primary · at baseline and month 6

Best corrected visual acuity is converted to logMAR (logarithms of minimum angle of resolution) by statistical calculation.

baseline

Group	Value	95% CI
Phenytoin	1.44	± 0.98
Placebo	1	± 0.83

6 months

Group	Value	95% CI
Phenytoin	0.04	± 0.067
Placebo	0.13	± 0.448

Visual Field Mean Deviation in Decibel Primary · Measured at baseline and month 6

The visual field is performed by the Swedish interactive thresholding algorithm standard 24-2 perimeter (Carl Zeiss mediated, Dublin, California).

Baseline visual field mean deviation (MD)

Group	Value	95% CI
Phenytoin	-17.07	± 11.41
Placebo	-17.76	± 11.81

6 months MD

Group	Value	95% CI
Phenytoin	-3.89	± 4.46
Placebo	-5.16	± 7.49

Retinal Nerve Fibre Layer Thickness in Micrometer Secondary · Measured at baseline and month1 ,6

Retinal nerve fibre layer thickness measure in 8 sectors by Heidelberg spectral-domain Optical Coherence Tomography

Baseline

Group	Value	95% CI
Phenytoin	131.8	± 36.56
Placebo	124.87	± 47.51

1 month

Group	Value	95% CI
Phenytoin	93.85	± 8.64
Placebo	97.41	± 23

6 months

Group	Value	95% CI
Phenytoin	77.7	± 20.03
Placebo	78.61	± 18.97

Adverse events — posted to ClinicalTrials.gov

Time frame: 6 months. Reporting threshold: 0%. Adverse-event reports describe events observed during the trial — not all are caused by the drug.

Phenytoin

Serious: 1/21 (5%)

Deaths: 0/21

Placebo

Serious: 0/50 (0%)

Deaths: 0/50

Serious adverse events (1 terms)

Reaction	System	Phenytoin	Placebo
steven johnson	Skin and subcutaneous tissue disorders	—	—

Other adverse events (1 terms — click to expand)

Reaction	System	Phenytoin	Placebo
skin reaction	Skin and subcutaneous tissue disorders	—	—

Most-reported serious reactions: steven johnson.

Data from ClinicalTrials.gov NCT02939937 adverse events section.

Sponsor's own description

Optic neuritis typically occurs in young (mean age, 32 years), female (77%) patients, and it presents as subacute monocular visual loss that develops over several days.

As yet, treatment with intravenous corticosteroid for optic neuritis had no long-term beneficial effect on vision.

There are a number of factors that contribute to nerve fibre damage including increased level of sodium, so blocking sodium entry could help to protect them against damage.

The main objective of the study is determine whether phenytoin (which blocks sodium entry) can protect nerve fibre and improve final visual function after optic neuritis.

Publications & conference data

No peer-reviewed publications indexed yet for this trial. Completed trials usually publish results within 12-18 months.