Work

183 An accelerated, scalable manufacturing platform generates highly purified and functionally superior CAR T cell products for chronic lymphocytic leukemia

Year: 2026

Type: conference-paper

Abstract: Background Autologous CAR T-cell therapy has transformed B cell malignancy treatment, but efficacy against chronic lymphocytic leukemia (CLL) remains elusive with only 18% of patients achieving complete remission in the most recent clinical trial (TRANCEND CLL 004). 1 This is partly due to variable patient starting material, often dominated by leukemic B-cells, monocytes, suppressive populations, and dysfunctional T-cells. These detrimental cells compromise manufacturing, reduce product potency, and result in variable outcomes. We developed a proprietary negative-selection based depletion and decentralized, rapid manufacturing platform, IMPACT (Integrated Manufacturing Platform for Advanced Precision CAR T cell manufacturing), to remove cellular liabilities while preserving T-cell subsets associated with potency, expansion, and persistence.Methods Normal donor and CLL patient PBMC/leukapheresis inputs were processed using IMPACT with a clinically validated CD19 CAR construct. Product composition was assessed by multiparameter flow cytometry at input, post-selection, and manufacturing endpoint. Phenotype stability was evaluated using markers of T-cell lineage, memory differentiation, regulatory/suppressive populations, activation, and dysfunction. Manual small-scale runs were compared with automated, modular, at-scale runs to assess process comparability. Functional potency was tested in repeat antigen stimulation assays against leukemia cells and benchmarked against an FDA approved standard CAR T-cell manufacture workflow.Results IMPACT reproducibly depleted cellular liabilities from heterogeneous normal donor and CLL patient inputs and generated a highly purified T-cell product, including CLL samples in which T-cells increased from 1.9% of input material to 98% of post selection material. B-cell, monocyte, NK-cell, regulatory, and differentiated/exhausted effector contaminants were reduced to near-zero after a single depletion workflow. The enriched product, maintained a favorable phenotype throughout manufacture, with preservation of early-memory features and very limited differentiation ( figure 1). Automated scaled manufacture reproduced the flow cytometry profile observed in manual small-scale runs, supporting process transferability and scalability. In repeat stimulation assays, IMPACT CAR T cells show superior leukemia control and expansion compared with a standard comparator product, even at effector target ratios of 1:30 (figure 2).Conclusions IMPACT generates highly purified, phenotypically favorable, and functionally potent CAR T-cell products from challenging CLL starting material. By combining selective removal of cellular liabilities with shortened on-site manufacture, this approach addresses two major barriers in CLL cellular therapy: impaired T cell fitness and manufacturing failures. Furthermore, IMPACT reduces vein to vein time, cost, and increases access to vulnerable and frail patients. These data support further development toward clinical translation. We are currently preparing a preclinical package for IND filing.Reference Siddiqi T, Maloney D, Kenderian S, et al. Lisocabtagene maraleucel in chronic lymphocytic leukaemia and small lymphocytic lymphoma (TRANSCEND CLL 004): a multicentre, open-label, single-arm, phase 1–2 study. The Lancet 2023;402:641–654.Ethics Approval Studies involving commercially purchased normal donor T cells or patient specimens were approved by the Cleveland Clinic Institutional Biosafety Committee (Protocol #2210). Patient specimen studies were approved by the Cleveland Clinic Review Board (Protocol 21-571).Abstract 183 Figure 2IMPACT CAR T-cell product improves proliferation. Cumulative population doublings of CAR T-cells when repeatedly stimulated with human leukemia cells (NALM-6). E:T start low to rigorously test CAR T-cell products and taper to reflect physiology. N = 3 NDs. p = 0.0152 paired T test of AUCAbstract 183 Figure 1IMPACT enriches and preserves highly potent T cells. Proportion of high potential T-cells (CD45+ CD3+TCRab+ CD127+ CD244-) of CD3+ population in PBMC, post-depletion, pre-manufacture and post-manufacture CAR T-cells. STD (CD4/CD8 positive selection, 12-day manufacture) N = 3 ND, p = 0.0174 paired T test

Source: Journal for ImmunoTherapy of Cancer

DOI: 10.1136/jitc-2026-sitc2026.0183