# Outcomes of idebenone therapy for Leber hereditary optic neuropathy in a cohort of patients from Wales

## TL;DR

This study shows that idebenone treatment improves vision in most patients with Leber hereditary optic neuropathy over 27 months.

## Contribution

The study provides real-world evidence of idebenone's efficacy in a Welsh NHS cohort with LHON.

## Key findings

- 86% of patients showed clinically relevant visual recovery after 27 months of idebenone treatment.
- Visual acuity improved significantly from 2.22 to 1.12 LogMAR over the treatment period.
- CRR was significantly higher in treated patients compared to a natural history cohort at 24 months.

## Abstract

Leber hereditary optic neuropathy (LHON) poses a significant burden to patients, with the majority not showing significant spontaneous improvement in their vision. The recent validation of idebenone as a therapy provides some avenue for benefit for patients with LHON in Wales, where it has been approved for use within the NHS.

From March 2021, all patients being seen in a tertiary referral clinic and diagnosed with LHON by targeted genetic testing were offered treatment with idebenone and commenced on idebenone as part of standard care. For such patients, their clinical records were used to collect demographic and outcome data. Visual acuity was analysed for clinically relevant recovery (CRR), defined as improvement from ‘off-chart’ to ‘on-chart’ or ‘on-chart’ improvement of at least 10 letters.

A total of 12 (67% male) individuals were treated with idebenone 300 mg TDS for LHON for a mean period of 30.2 (±9.9) months. Mean visual acuity at initiation of therapy was 2.22 (±0.32) LogMAR, improving to a peak of 1.12 (±0.77) LogMAR at 27 months. This time point was coincident with the maximum CRR achieved, with 86% demonstrating CRR. At 24 months, CRR was significantly higher when compared to a natural history cohort.

The present cohort demonstrates evidence of CRR in a high proportion of patients reaching 27 months of treatment. Further follow-up and a larger cohort of patients will provide further insight into the real-world efficacy of idebenone in LHON.