Association Between Pretreatment Skeletal Muscle and Outcomes After CAR T-Cell Therapy.

Abstract

The purpose of this study was to examine the association between baseline skeletal muscle measurements, acute toxicity (immune effector cell-associated neurotoxicity syndrome [ICANS], cytokine release syndrome), and treatment efficacy in patients undergoing CAR T-cell therapy for B-lineage lymphoma. Skeletal muscle measurements were obtained from automated CT measurements in 226 consecutive patients who received CAR T-cell therapy between 2015 and 2021. The Kaplan-Meier method was used to examine progression-free survival (PFS) and overall survival (OS) at 1-year. Multivariable regression was used to calculate the hazard ratio (HR) with 95% confidence intervals, adjusted for covariates. The median age of the cohort was 63.1 years (range, 18.5-82.4 years), and most patients were male (66%) and had primary refractory disease (58%). Patients with abnormally low skeletal muscle at baseline were at greater risk of ICANS (HR, 1.74; 95% CI, 1.05-2.87) and had longer length of hospitalization (mean 27.7 vs 22.9 days; P<.05) compared with those with normal muscle mass. Abnormal skeletal muscle was independently associated with risk of disease progression (HR, 1.70; 95% CI, 1.11-2.57) and worse survival (HR, 2.44; 95% CI, 1.49-4.00) at 1 year compared with normal skeletal muscle. Individuals who had abnormal skeletal muscle and high lactate dehydrogenase (LDH) levels at baseline had poor 1-year PFS (17%) and OS (12%) compared with those with normal skeletal muscle and LDH levels (72% and 82%, respectively; P<.001). Patients who had abnormal skeletal muscle and LDH levels had a 5-fold risk (HR, 5.34; 95% CI, 2.97-9.62) of disease progression and a 10-fold risk (HR, 9.73; 95% CI, 4.81-19.70) of death (reference: normal skeletal muscle, normal LDH), independent of prior lines of therapy, extent of residual disease at time of CAR T-cell therapy, functional status, or product. This information can be used for risk stratification prior to CAR T-cell therapy or to implement prehabilitation and nutritional optimization before lymphodepletion as well as thereafter. These efforts will be complementary to ongoing efforts toward sustained efficacy after CAR T-cell therapy.