The risk of cytokine release syndrome (CRS) after chimeric antigen receptor (CAR) T-cell therapy may vary by ethnicity and body mass index (BMI), according to research presented at the 2021 AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved.
The study showed significantly higher rates of CRS among Hispanic patients and numerically higher rates of CRS among obese patients. On the other hand, there were no differences in complete response (CR) to CAR T-cell therapy by race, ethnicity, or BMI.
For this study, Paul Borgman III, of the National Cancer Institute in Bethesda, Maryland, and colleagues retrospectively reviewed 5 phase 1 trials of CAR T-cell therapy in children and adults with B-cell malignancies.
Of the 185 patients studied, 138 had acute lymphoblastic leukemia and received anti-CD19 CAR-T cells, anti-CD22 CAR-T cells, or CAR-T cells targeting both CD19 and CD22. An additional 23 patients with non-Hodgkin lymphoma received anti-CD19 CAR-T cells, and 24 patients with multiple myeloma received anti-BCMA CAR-T cells.
The patients’ median age was 19.3 years (range, 4.3-69 years), and 65.9% were men. A total of 28 patients (15.1%) were deemed obese, which was defined as having a BMI of 30 or higher.
A majority of patients were White (83.2%), 7.6% were Asian, 5.4% were African American, 0.5% were Hawaiian/Pacific Islanders, and 3.2% were mixed race. Nearly a quarter of patients (24.3%) were Hispanic.
Results: CR and CRS
The CR rate was 57.3% overall, and there were no significant differences in CR by race, ethnicity, or obesity. The CR rate was 50% in obese patients and 58.6% in non-obese patients (P =.414).
The CR rate was 57.1% in White patients and 58.1% in non-White patients (P >.999). It was 57.7% in Hispanic patients and 56.8% in non-Hispanic patients (P >.999).
Grade 3 or higher CRS occurred in 24.7% of patients overall, and the incidence did not vary significantly by race. Grade 3 or higher CRS occurred in 19.5% of White patients and 16.1% of non-White patients (P =.804).
However, the rate of grade 3 or higher CRS was significantly higher in Hispanic patients than in non-Hispanic patients — 28.9% and 15.1%, respectively (P =.048).
The incidence of grade 3 or higher CRS in obese patients was nearly double the incidence in non-obese patients — 32.1% and 16.6%, respectively — but this difference was not statistically significant (P =.067).
“We had very interesting findings where certain groups were experiencing grade 3 and over CRS at very high rates,” Mr Borgman said. “Those definitely warrant further investigation because those are clinically relevant findings.”
Borgman P, Ligon J, Yates B, et al. The impact of race, ethnicity and obesity on CAR T-cell outcomes. Presented at: AACR 2021 Virtual Cancer Health Disparities; October 6-8, 2021. Abstract PO-111.