Population-Based External Validation of the CAR-Hematotox Score to Predict CAR T Cell Related Toxicity and Outcome in R/R LBCL Patients

• Published in: Blood 2024-11, Vol.144, p.1747-1747
• Main Authors: de Boer, Janneke W., Keijzer, Kylie, van Dorp, Suzanne, Mutsaers, Pim G.N.J., Niezink, Anne G.H., van Doesum, Jaap A., Serroukh, Yasmina I.M., Muntendam, Louise W., Pulles, Astrid E., Kret, Esther J., Sijs-Szabo, Aniko, Oomen, Jesse, Demandt, Astrid M.P., Stevens, Wendy B.C., Kuipers, Maria T., Pennings, Elise R.A., Spanjaart, Anne M., Kersten, Marie José, Jak, Margot, van Dijk, Lisanne V., van der Poel, Marjolein W.M., Vermaat, Joost S.P., van Meerten, Tom
• Format: Article
• Language: English
• ISSN: 0006-4971
• DOI: 10.1182/blood-2024-209879

Early identification of patients with an increased risk for immune effector cell-associated hematotoxicity (ICAHT) is essential to enable early intervention and thereby minimize non-relapse mortality due to toxicities and infections. Therefore, the CAR-HEMATOTOX (HT) score has been proposed as a risk-stratification tool for ICAHT, infections and outcome in patients with relapsed or refractory large B-cell lymphoma (R/R LBCL) treated with CAR T cell therapy (CART) (Rejeski et al. Blood 2021; Rejeski et al. JITC 2022). This easy-to-use score is widely implemented and recommended by EHA/EBMT as prediction score for ICAHT with subsequent treatment advices (Rejeski et al. Blood adv 2023). Although the HT score was validated in the HT defining study, it was developed in a rather small cohort (n=55), with a low positive predictive value. As no fully external multicenter validation has been performed, a comprehensive independent validation study is warranted. This study aims to externally validate the HT score in an independent population-based real-world LBCL CART cohort. Adults with R/R LBCL after ≥2 lines of systemic therapy who received CART as standard of care between May 2020 and December 2023 across all 7 Dutch CART centers were included. HT score was calculated per the original report, including absolute neutrophil count (ANC), hemoglobin (Hb), platelet count, C-reactive protein (CRP) and ferritin, determined prior to lymphodepleting chemotherapy. A high HT score was defined as HT score ≥2 (HThigh). Patients with at least 3 out of 5 laboratory parameters were included. Missing laboratory values were imputed with predictive mean matching and pooled results are reported. Endpoints included clinically significant neutropenia (ANC