Correlation of patient characteristics and biomarkers with clinical outcomes of JCAR017 in R/R aggressive B-NHL (TRANSCEND NHL 001 study).

Abstract

122 Background: JCAR017 is a defined composition, CD19-directed 4-1BB CAR T cell product administered at a precise dose of CD8 and CD4 CAR T cells in a seamless design Ph1 pivotal trial of R/R B-cell NHL (TRANSCEND NHL 001; NCT02631044). Methods: Blood samples were collected for biomarker analyses at protocol-defined time points. PK (CAR T cell expansion and persistence) was measured using flow cytometry. Cytokines were measured on a Luminex platform. Additional analytes will be presented. All reported p-values are 2-sided without multiplicity adjustment. Results: Safety (n = 59) and efficacy (n = 54) outcomes were analyzed for correlations with patient (pt) characteristics and biomarkers. Dose level did not correlate with cytokine release syndrome (CRS) or neurotoxicity (NT) despite higher median Cmax and median AUC0-28 at DL2. In pts with NT or ≥Gr 2 CRS, CD4 and CD8 CAR T cell levels were 5-10 fold and 3-5 fold higher, respectively, than median DL2 levels. Pt factors that correlated with any grade CRS and NT were ECOG 2 (p = 0.03) and high disease burden (p < 0.05). Higher levels of IL-8, IL-10, and CXCL10 before CART cell infusion were associated with Gr 3-4 NT (each p< 0.05), suggesting that inherent pt factors may result in higher CAR T expansion and associated CRS and NT. Lower pre-CAR T cell ferritin, LDH, CXCL10, G-CSF, and IL-10 were associated with CR/PR, and lower pre-CAR T cell ferritin, CRP, LDH, CXCL10, IL-8, IL-10, IL-15, MCP-1, MIP-1β, TNF-α were associated with 3-month durable response (each p< 0.05). Median Cmax and AUC0-28 of CD8 CAR T cells were higher in responding patients and with durable response at Month 3 (CD8 Cmax median = 20.8 vs 5.5; CD8 AUC median = 235 vs 55 in CR/PR vs PD at Month 3). Of pts evaluable for persistence at 3 months (n = 29), 90% and 93% had detectable CD8+ and CD4+ CAR+ T cells; of those with available PK results at time of relapse (n = 11), 82% had persistence at time of relapse. Conclusions: JCAR017 demonstrated increased CAR T cell expansion and persistence and higher durability of response at higher dose levels, with manageable toxicities. CAR T cells were also detected at time of relapse, suggesting potential opportunities for future combination clinical trials. Clinical trial information: NCT02631044.