To validate at-home digital biomarkers for monitoring changes in upper and lower limb function in Inclusion Body Myositis (IBM).

IBM results in physical disability due to progressive muscle weakness. Assessment of function is quantified in clinical care and research settings using a combination of clinician-assessed scales for muscle strength and function, as well as the IBM Functional Rating Scale (IBMFRS).

This is a 24-month prospective study in 20 IBM patients undergoing assessments at baseline, 6, 12, 18, and 24 months. IBMFRS is assessed during each visit along with strength measures and patient-related outcomes. Participants are given a PAMSys^TM pendant and 2 PAMSys ULM^TM wrist sensors for at-home monitoring of physical activity, posture and upper limb function for 7 consecutive days after each visit.

Twenty participants have been enrolled in the study. An interim analysis of the first 19 individuals diagnosed with IBM (mean age 71.0±7.3 years, 11 female) with IBMFRS ranging 14 to 35 show that sensor-derived measures of physical activity collected after the baseline visit have significant correlation with the lower extremity subdomain score of the IBMFRS (items 7–10) with correlations ranging from r =-0.559 to 0.674. Similarly, sensor-derived measures of hand function demonstrated moderate to strong correlations with the upper extremity subdomain score of the IBMFRS (items 2–6), with correlations r = 0.509 to 0.615.

While this study is ongoing, interim analysis of the baseline data indicate that at home wearable-based monitoring has the potential to track physical dysfunction in IBM effectively. Wearable sensors provide objective data, increased convenience, and offer scalability and cost-effectiveness, thereby advancing clinical care and potentially improving future clinical trials in IBM. We plan to present data on all 20 participants at the meeting.