A prospective trial published in JCI Insight shows that continuous wearable monitoring detected cytokine release syndrome a median of seven hours before standard nursing care. This blog explores what the additional notice means for outpatient advanced therapy programs.
The problem that outpatient CAR-T has to solve
CAR-T therapy has changed what’s possible for patients with relapsed/refractory multiple myeloma, lymphoma, and leukemia. With outpatient delivery accelerating following the removal of REMS requirements in 2025, translational research has shifted to optimizing intervention timing and delivery for the most common, and most costly, complications.
A study conducted in collaboration with clinical researchers at Mount Sinai and published in JCI Insight shines a new light on the early detection possible through the Current Health platform, pointing toward operational and clinical advantages for programs that deploy a passive monitoring approach.
Study description
Rajeeve and colleagues enrolled 30 patients with RRMM receiving ide-cel or cilta-cel at Mount Sinai Hospital. Patients wore the Current Health monitoring device continuously from infusion through discharge, capturing skin temperature, pulse rate, oxygen saturation, respiratory rate, and motion, paired with an axillary temperature patch. Clinicians and patients were blinded to the device output and the device ran as a “black box” alongside standard nursing observations every four hours. Peripheral blood cytokine profiles were collected pre- and post-infusion.
The primary endpoint was feasibility, measured by sensitivity and specificity for CRS detection. Twenty-five patients had sufficient monitoring data for analysis; twenty of them developed CRS, almost all Grade 1.
Seven-hour CRS lead time
The best-performing model, which combined axillary temperature with an individualized baseline and a 36.4°C threshold over a 60-minute observation window, detected 18 of 20 CRS episodes. Sensitivity was 0.72 (mean 0.75; 95% CI 0.60–0.91) and specificity was 0.80 (mean 0.76; 95% CI 0.68–0.84). The median lead time before standard nursing recognition was 7 hours (IQR 3:16).
For comparison, applying the ASTCT-defined 38.0°C threshold to the same data identified only 12 of 20 episodes, with a median lead time of 1:45 hours.
The implication: the temperature value that defines Grade 1 CRS clinically is a relatively late signal when monitoring temperature continuously. A lower, individualized threshold detected the same physiologic event substantially earlier, while maintaining specificity above 0.80.
The value of a 7-hour window for CRS detection
The lead time is the most significant finding of this study. Inpatient programs or outpatient models that rely on intermittent vital signs may catch CRS at a four-hour check, or sooner if the patient reports symptoms. Manual observation generates more urgent escalations, which can drive up costs and impede program scalability. Seven hours of additional notice changes the calculus for outpatient programs in five ways:
- Time to intervene. A patient at home who triggers an alert based on an individualized threshold can be assessed, advised, and brought in for tocilizumab well before they reach the 38.0°C fever threshold that would otherwise be the first clinical signal.
- Time to triage. Not every temperature elevation will be CRS. A seven-hour window allows for a phone or video assessment, repeat measurements, and a considered decision rather than a reactive admission.
- Time to coordinate. Home health, transport, and inpatient capacity can be mobilized before the patient is acutely unwell.
- Broader patient eligibility. An earlier lead time for CRS holds the potential to increase the radius of eligible lodging for patients receiving their therapy as outpatients.
- Stronger foundation for scale. With advanced notice of the most common reason for hospitalization, programs can confidently take on more patients and efficiently plan for escalations.
This is the difference between monitoring that confirms CRS and monitoring that anticipates it.
Implications for outpatient CAR-T programs
A seven-hour lead time on CRS is only as valuable as the infrastructure behind it. Early detection through passive monitoring creates a window for intervention, but proactive care requires 24/7 nurse monitoring capabilities and escalation protocols precise enough to distinguish a meaningful signal from noise. Without that infrastructure, early alerts don’t translate to changes in care.
The findings support real-world outpatient observations across the Current Health customer base, which often finds CRS early detection alarms precede noticeable patient symptoms. Outreach from a nurse at this early point serves to build trust and increase feelings of safety and security for both the patient and caregiver.
For programs working to expand outpatient CAR-T delivery without expanding bed capacity, the combination of passive monitoring and a responsive nurse layer is where confidence in the model is built. And with each patient encounter, the data accumulating across a program creates a clearer picture of what good looks like, and how to get there faster.
Rajeeve S, Wilkes M, Zahradka N, et al. Detection of cytokine release syndrome using wearables and cytokine profiling following CAR-T therapy for myeloma. JCI Insight. 2026. https://doi.org/10.1172/jci.insight.203988