Rossi et al. utilized a T cell polyfunctionality strength index (PSI) to evaluate preinfusion CD19-targeted CAR T cells used to treat non-Hodgkin lymphoma. Although only 20% to 25% of cytokine-producing product T cells were polyfunctional, PSI correlated with objective response and grade 3+ cytokine release syndrome. The association was stronger when combined with markers of in vivo CAR T cell expansion or Day 0 IL-15 levels, particularly for CD4+ T cell subsets. Polyfunctional T cells expressing IL-17A were associated with grade 3+ neurotoxicity and antitumor efficacy.

After treatment with chimeric antigen receptor (CAR) T cells, interleukin (IL)-15 elevation and CAR T-cell expansion are associated with non-Hodgkin lymphoma (NHL) outcomes. However, the association of preinfusion CAR product T-cell functionality with clinical outcomes has not been reported. A single-cell analysis of the preinfusion CD19 CAR product from patients with NHL demonstrated that CAR products contain polyfunctional T-cell subsets capable of deploying multiple immune programs represented by cytokines and chemokines including interferon-gamma (IFN-gamma), IL-17A, IL-8, and macrophage inflammatory protein 1-alpha. A prespecified T-cell polyfunctionality strength index (PSI) applied to preinfusion CAR product was significantly associated with clinical response, and PSI combined with CAR T cell-expansion or pretreatment serum IL-15 levels conferred additional significance. Within the total product cell population, associations with clinical outcomes were greater with polyfunctional CD4+ T cells compared with CD8+ cells. Grade 3+ cytokine release syndrome was associated with polyfunctional T cells, and both grade 3+ neurologic toxicity (NT) and antitumor efficacy were associated with polyfunctional IL-17A-producing T cells. The findings in this exploratory study show that a preinfusion CAR product T-cell subset with a definable polyfunctional profile has a major association with clinical outcomes of CAR T-cell therapy.

Author Info: (1) Kite, a Gilead Company, Santa Monica, CA, United States. (2) IsoPlexis, Branford, CT, United States. (3) Kite, a Gilead Company, Santa Monica, CA, United States. (4) IsoPlexis,

Author Info: (1) Kite, a Gilead Company, Santa Monica, CA, United States. (2) IsoPlexis, Branford, CT, United States. (3) Kite, a Gilead Company, Santa Monica, CA, United States. (4) IsoPlexis, Branford, CT, United States. (5) IsoPlexis, Branford, CT, United States. (6) IsoPlexis, Branford, CT, United States. (7) IsoPlexis, Branford, CT, United States. (8) IsoPlexis, Branford, CT, United States. (9) IsoPlexis, Branford, CT, United States. (10) Yale School of Engineering and Applied Science, Yale University, New Haven, CT, United States. (11) IsoPlexis, Branford, CT, United States. (12) Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, United States. (13) Surgery Branch, National Institutes of Health, Betheda, MD, United States. (14) Experimental Transplantation and Immunology Branch, National Institutes of Heath, Betheda, MD, United States. (15) IsoPlexis, Branford, CT, United States. (16) Kite, a Gilead Company, Santa Monica, CA, United States abot@kitepharma.com.