Objective: To assess the impact of Friedreich ataxia (FA) on the activities of daily living associated with dexterity at different levels of disease severity.
Background: FA is an autosomal-recessive, degenerative disease characterized by a decline in mobility and dexterity, affecting quality of life. There are limited data on how FA progression impacts dexterity as measured by the FA activities of daily living (FA-ADL) scale, and its association with the modified Friedreich’s Ataxia Rating Scale (mFARS). Omaveloxolone slowed disease progression in the MOXIe Part 2 (MOXIe) trial vs. placebo. The Friedreich’s Ataxia Clinical Outcome Measures Study (FACOMS) registry provides 13 years of natural history data for patients with FA.
Methods: FA-ADL questions about dexterity (Q3: cutting food and handling utensils, Q4: dressing and Q5: personal hygiene) were assessed separately in both the FACOMS and MOXIe datasets to determine the proportion of patients with a score at or above the lower bound of selected 10-point mFARS ranges. All FA-ADL questions are scored 0-4 with higher scores representing worse outcomes.
Results: The percentage of patients with a score ≥3 on the FA-ADL cutting food question (meaning at minimum food needs to be cut by someone or eaten slowly) doubled for patients with an mFARS score 50-59 compared to 40-49 in FACOMS (10% vs. 5%). This was reflected in MOXIe (15% vs. 5%).
In FACOMS, 34% of patients with mFARS scores of 40-49 scored ≥2 on the FA-ADL dressing question (meaning at minimum assistance with buttoning or putting arms in shirt sleeves) compared to 20% for scores of 30-39. This was comparable in MOXIe with scores of 28% and 18% respectively.
The percentage of patients with a score of ≥2 on the FA-ADL hygiene question (meaning at minimum the need for devices like grab bars or some support with washing) was higher for patients with an mFARS score 40-49 (35% for FACOMS, 36% for MOXIe) compared with those with a score 30-39 (15% FACOMS and 8% MOXIe).
Conclusions: Dexterity outcomes measured by FA-ADL have a strong association with mFARS score, suggesting that mFARS can also capture dexterity progression in FA.