AACR: Myocarditis in First Month of Immune Checkpoint Inhibitor Therapy Predictive of Fatality

THURSDAY, April 23, 2026 (HealthDay News) -- Patients who develop myocarditis (MC) within the first month of receiving immune checkpoint inhibitor (ICI) therapy are more likely to have MC fatality, according to a study presented at the annual meeting of the American Association for Cancer Research, held from April 17 to 22 in San Diego.Hassan Mohammed Abushukair, M.D., from the University of Oklahoma Stephenson Cancer Center in Oklahoma City, and colleagues reported the largest clinical series of ICI-induced MC, which often overlaps with myositis (MS) and myasthenia gravis (MG), forming the fulminant triad of "triple M overlap syndrome" (TMOS). A machine learning model was constructed using a subset of 858 ICI-MC cases, with an 80/20 percent data split for training and internal testing. For independent validation, an external public real-world dataset of 28 ICI-MC cases was used.The researchers identified 2,641 ICI-MC cases, of which 72.4 and 27.6 percent were MC alone and overlapping with MS and/or MG, respectively. MC-specific fatality rates were higher in TMOS, MC alone, MC+MS, and MC+MG (38 percent versus 21.2, 22.5, and 25.7 percent, respectively). After adjustment for age, ICI regimens, cancer type, and coreactions, early-onset MC within the first month of ICI initiation was independently associated with increased MC fatality (odds ratios, 0.41 and 0.44 for no more than one versus one to three and three to 12 months, respectively). An area under the curve of 0.79, 0.75, and 0.85 was seen for the final MC fatality classifier for the training, internal testing, and external validation sets, respectively. The top predictive features for MC fatality were early-onset MC occurrence and cardiorespiratory coreactions."Our analysis indicates that the first month of a patient receiving ICI therapy is the crucial period for determining patients' risk of myocarditis fatality," Abushukair said in a statement.Press ReleaseMore Information

AACR: Myocarditis in First Month of Immune Checkpoint Inhibitor Therapy Predictive of Fatality

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