P-043: Leveraging wearable devices for remote patient monitoring facilitate earlier CRS detection following CAR-T therapy in relapsed/refractory multiple myeloma (RRMM): Early results from an IIT

Introduction: Chimeric Antigen Receptor T-cell (CAR-T) therapy includes a prolonged inpatient stay to monitor for cytokine release syndrome (CRS). Shifting the site of care to the outpatient setting may improve patient experience, limit healthcare utilization and decrease costs, but monitoring patients remotely requires reliable CRS detection. The feasibility of using a wearable device for detecting CRS following CAR-T therapy in RRMM was compared to standard of care (SoC) in an investigator initiated clinical trial (IIT).

Methods: Patients wore a wearable (Current Health Inc.) to collect continuous measures of temperature, pulse, respiratory rate, and O2 saturation in addition to SoC from CAR-T infusion to discharge. Fever was captured as the earliest and consistent marker of CRS per ASTCT criteria. CRS timestamps were tagged in wearable data 1) when pt’s temperature breached a fixed threshold of 38C (Tf), and 2) when pt’s temperature breached an individualized threshold of 2 standard deviations above their baseline temperature (Ti). Outcomes were time to detection of CRS in wearable data vs. SoC. Adherence was the duration pts wore the wearable over the total monitoring period.

Results: To date, 24 pts were screened, 22 enrolled (91.7% uptake) and 1 excluded because of concurrent COVID-19. The 21 pts had a total of 41 CRS events - max grades 0 (5 pts), 1 (14 pts), 2 (1 pt), and 3 (1 pt). Patients wore the device for a median of 13 (12-15) days. Median individualized temperature threshold was 37.4 (37-37.6) C. Wearable adherence was 68 (50-81) % and 73 (60 – 88) % for the overall monitoring and high-risk periods, respectively (1 pt had limited data during the high-risk window so was excluded from the comparisons that follow). By temperature thresholds, the wearable detected initial CRS events at a median of 46 (18 - 114) mins earlier than SoC with Tf and a median of 206 (134 - 312) mins earlier than SoC with Ti method. In the no CRS subgroup, false CRS detection occurred in 1 pt with the Tf and 2 pts with the Ti method. There were no missed events.

Conclusions: Preliminary results suggest that detection of CRS by the wearable device preceded SoC by a median of 126 mins. The breach of individualized temperature thresholds (Ti) facilitated a much earlier detection than breach of fixed thresholds (Tf) which is still earlier than SoC. Earlier detection of CRS affords a lead time to intervene. The low false detection rate is encouraging, and may be evidence of the wearable detecting ‘subclinical’ events that did not meet ASTCT criteria despite derangement of ≥1 vital signs. The study showcases the utility of continuous vital signs monitoring in capturing CRS, including earlier detection and potentially subclinical events. Reliable CRS monitoring using wearables may help transition workflows to outpatient CAR-T administration. In parallel, correlating early detection of CRS with cytokines drawn in the immediate post CAR-T infusion period is being worked on and will be presented at the meeting.