CD62L enrichment achieves robust expansion and memory phenotype post-infusion in patients with LBCL treated with rondecabtagene autoleucel, an autologous, dual-targeting CD19/CD20 CAR T-cell candidate

Abstract Background: Durable complete response remains the therapeutic goal when treating patients with large B-cell lymphoma (LBCL) with chimeric antigen receptor (CAR) T-cell therapy. Despite the benefit of approved CD19 CAR T-cell therapies, approximately 50% of patients with third- or later-line (3L+) relapsed or refractory (R/R) LBCL treated with CD19 CAR T-cell therapies progress by 6 months. Higher memory marker expression and lower exhaustion marker expression in FDA-approved CD19 CAR T-cell drug products have been associated with favorable clinical outcomes (Deng et al 2020). CD62L is a known cell surface marker for stem-like memory and central memory T-cells (Gattinoni et al 2017). Rondecabtagene autoleucel (ronde-cel, LYL314) is an autologous, dual-targeting CD19/CD20 CAR T-cell therapy product candidate manufactured from CD62L+ enriched cells. This manufacturing process is designed to maximize memory properties, reduce T-cell exhaustion, and enhance cell persistence in the drug product, and does not extend conventional manufacturing time. An ongoing Phase 1/2 multi-center trial (NCT05826535) in 2L and 3L+ LBCL is evaluating ronde-cel, which has achieved high rates of durable responses (Merchant et al 2025). Here, we present translational data in patients treated in the 2L and 3L+ setting, highlighting that CD62L+ enrichment achieves greater memory phenotype expression and in vivo cell expansion compared to published data from FDA approved CAR T-cell therapies in LBCL. Enrollment is ongoing and additional data will be available at the time of the conference. Methods: Phenotype of ronde-cel drug products was assessed by flow cytometry and single-cell RNAseq. Peripheral blood (PB) was collected post infusion at multiple time-points, and CAR T-cell pharmacokinetics (PK) (ddPCR) and phenotype (flow cytometry) were assessed. Results: Ronde-cel products (N = 53) are composed of, on average, 99% CD3+ cells (range: 89 – 100%), 59% CAR+ cells (17 – 79%), and 95% CD62L+ of CD3+ cells (84 – 99%). Transcriptomic analyses on the CD8+CAR+ compartment of ronde-cel products (N = 19) shows higher expression of memory-related genes such as CD62L, IL7R, and CCR7 and lower expression of exhaustion-associated genes such as TIGIT, PD-1, and LAG3 compared to an approved CD19 CAR-T therapy (Li et al 2023). Beyond individual genes, gene set analyses (Hänzelmann et al 2013) reveal that stem-like gene sets (Jansen et al 2019) and effector-memory gene sets (Sade-Feldman et al 2018) are significantly upregulated (adjusted p values = 6.4e-6 and 2.5e-3, respectively) in ronde-cel products compared to approved CD19 CAR T-cell therapy with available data (Li et al 2023). Conversely, exhaustion-associated gene sets are downregulated (adjusted p value = 1.8e-4) in ronde-cel products. Flow cytometry profiling on PB mononuclear cells from Day 14 after ronde-cel infusion (N = 14) showed that CD8+CAR+ cells are predominantly of memory phenotype (median of 98% and standard deviation of 19%, as defined by CD45RO+/CD45RA-). The enhanced memory phenotype of ronde-cel products enabled robust CAR T-cell expansion post infusion (N = 54) with a peak (Cmax) of 83,423 copies/µg (1,387 – 569,039), AUC of 898,191 days x copies/µg (14,596 – 9,109,115), and time to peak of 10 days (7 – 28). Median peak expansion (Cmax) and exposure (AUC) for ronde-cel is at least 3x higher than FDA approved CAR T-cell therapies (Abramson et al 2020, Schuster et al 2019). Finally, higher CAR T-cell exposure (AUC) was positively correlated with increased effector-memory gene set scores measured in ronde-cel products (r = 0.65, p = 0.01, N = 15). Conclusions: Ronde-cel manufactured after CD62L enrichment resulted in increased stem-like and effector-memory properties in the infusion product compared to FDA approved CD19 CAR T-cell therapies in LBCL. These properties are positively correlated with robust expansion observed in patients and a high memory phenotype post infusion. These findings support the potential of ronde-cel to achieve improved clinical outcomes through enhanced product characteristics. Ronde-cel with CD62L enrichment is being evaluated in two pivotal trials, the ongoing PiNACLE trial in the 3L+ setting and a second randomized controlled trial in the 2L setting.