Researchers have found that wearable devices may help clinicians detect cytokine-release syndrome—a common and potentially serious side effect of chimeric antigen receptor (CAR) T-cell therapy—hours earlier than standard hospital monitoring in patients with multiple myeloma.
The findings, published by Rajeeve et al in JCI Insight, suggest wearable technology could help make CAR T-cell therapy safer, expand access to treatment, and reduce reliance on prolonged hospital stays.
CAR T-cell therapy is a powerful treatment for relapsed or refractory multiple myeloma. However, patients receiving CAR T-cell therapy are at risk for cytokine-release syndrome, an inflammatory reaction that can cause fever, low blood pressure, breathing problems, and other serious complications. It falls under the "cytokine storm" umbrella, commonly associated with immunotherapies like CAR T-cell cancer treatments. Because of this risk, many patients require hospitalization or intensive monitoring after treatment to ensure complications are identified and treated promptly.
In this pilot study, Mount Sinai researchers evaluated whether wearable sensors could continuously monitor patients for early signs of cytokine-release syndrome and detect problems earlier than standard nursing assessments.
“Our study shows that wearable temperature monitoring may provide an early warning sign that a patient is beginning to develop [cytokine-release syndrome],” said senior corresponding author Samir Parekh, MD, Professor of Medicine (Hematology and Medical Oncology) at the Icahn School of Medicine at Mount Sinai. “If validated in larger studies, this approach could help expand access to CAR T-cell therapy by supporting safer outpatient treatment models and reducing the need for prolonged hospitalization.”
The prospective study enrolled 30 patients receiving CAR T-cell therapy for multiple myeloma at The Mount Sinai Hospital. Researchers used wearable devices to continuously monitor patients’ skin and underarm temperature, heart rate, oxygen levels, breathing rate, and motion. Blood samples were also collected to study cytokines, which are linked to cytokine-release syndrome.
Among 25 evaluable patients, the wearable monitoring system detected 18 of 20 cytokine-release syndrome episodes and identified signs of toxicity a median of 7 hours before standard nursing recognition. Toxicity occurs when the immune system becomes hyperactive and releases excessive inflammatory proteins into the bloodstream. Researchers also found that changes in interferon gamma (IFN-γ) closely tracked temperature changes and may help improve future prediction models.
“Continuous monitoring gave us a clearer picture of how [cytokine-release syndrome] develops in real time,” said co-corresponding author Adriana Rossi, MD, Associate Professor of Medicine (Hematology and Medical Oncology) at the Icahn School of Medicine at Mount Sinai. “Earlier detection could allow clinicians to intervene sooner, potentially reducing complications and improving the patient experience.”
The researchers say the findings could help expand CAR T-cell therapy into outpatient and community-based settings, enabling patients to recover at home and improving access for patients who live far from major cancer centers.
“This work highlights the potential of combining wearable technology with biologic markers to improve cancer care,” said co-corresponding author Alessandro Laganà, PhD, Assistant Professor of Genetics and Genomic Sciences and Oncological Sciences at the Icahn School of Medicine at Mount Sinai. “Our long-term goal is to develop smarter monitoring systems that help clinicians predict toxicity earlier, personalize care, and improve outcomes for patients receiving advanced cancer therapies.”
The authors caution that the study was small and conducted at a single center. Larger studies will be needed to confirm the findings, particularly in outpatient CAR T-cell treatment settings.
DISCLOSURE: The study was supported by Bristol Myers Squibb and the Center of Excellence for Multiple Myeloma Philanthropic Fund. For full disclosures of the study authors, visit insight.jci.org.

