Objective:

Evaluate feasibility to monitor daily activity and assess functional outcomes using wearable sensor devices in an open label study (OLS) of losmapimod in facioscapulohumeral muscular dystrophy (FSHD).

Background:

Evaluation of clinical outcome assessments in FSHD is challenging due to the variable onset, severity, and progression. Fulcrum is evaluating the safety and efficacy of losmapimod for the treatment of FSHD with selected clinical outcome assessments in the ongoing OLS. Assessment with wearables may be a sensitive measure of upper extremity function, activities of daily living, and mobility in FSHD.

Design/Methods:

ActiMyo wearable activity monitoring devices were provided to participants in the OLS to be placed on 1 wrist and on 1 ankle. Activity was monitored during the day in the outpatient setting intermittently; alternating two weeks on and two weeks off until the end of the study. An 8-week baselining period was collected, with similar wear frequency, prior to initiating treatment. Participants performed prescribed movements of upper and lower extremities twice daily.

Results:

Fourteen subjects, ages 18 to 65 years with genetically confirmed FSHD1 and clinical severity score of 2 to 4 (range 0-5), received 15 mg losmapimod twice daily and completed the study over 60 weeks. Compliance for wearing the devices was 99%. All 14 participants were monitored for a total of 2941 days or 36758 hours, for an average of 2626 hours per participant. Multiple parameters calculated from the upper and lower extremities were found to be reliable (ICC > 0.90). Analysis of correlations with clinical outcome assessments will be reported.

Conclusions:

Measurement of functional performance in FSHD patients using wearable sensors is feasible, reliable, and correlates with multiple clinical outcome assessments, activities of daily living, and mobility. This assessment could provide critical data about disease progression and treatment efficacy in future clinical trials.