Reducing Ex Vivo Culture Improves the Antileukemic Activity of Chimeric Antigen Receptor (CAR) T Cells.
Saba GhassemiSelene Nunez-CruzRoddy S O'ConnorJoseph A FraiettaPrachi R PatelJohn SchollerDavid M BarrettStefan M LundhMegan M DavisFelipe BedoyaChangfeng ZhangJohn LeferovichSimon F LaceyBruce L LevineStephan A GruppCarl H JuneJan Joseph MelenhorstMichael C MilonePublished in: Cancer immunology research (2018)
The success of chimeric antigen receptor (CAR)-mediated immunotherapy in acute lymphoblastic leukemia (ALL) highlights the potential of T-cell therapies with directed cytotoxicity against specific tumor antigens. The efficacy of CAR T-cell therapy depends on the engraftment and persistence of T cells following adoptive transfer. Most protocols for T-cell engineering routinely expand T cells ex vivo for 9 to 14 days. Because the potential for engraftment and persistence is related to the state of T-cell differentiation, we hypothesized that reducing the duration of ex vivo culture would limit differentiation and enhance the efficacy of CAR T-cell therapy. We demonstrated that T cells with a CAR-targeting CD19 (CART19) exhibited less differentiation and enhanced effector function in vitro when harvested from cultures at earlier (day 3 or 5) compared with later (day 9) timepoints. We then compared the therapeutic potential of early versus late harvested CART19 in a murine xenograft model of ALL and showed that the antileukemic activity inversely correlated with ex vivo culture time: day 3 harvested cells showed robust tumor control despite using a 6-fold lower dose of CART19, whereas day 9 cells failed to control leukemia at limited cell doses. We also demonstrated the feasibility of an abbreviated culture in a large-scale current good manufacturing practice-compliant process. Limiting the interval between T-cell isolation and CAR treatment is critical for patients with rapidly progressing disease. Generating CAR T cells in less time also improves potency, which is central to the effectiveness of these therapies. Cancer Immunol Res; 6(9); 1100-9. ©2018 AACR.
Keyphrases
- cell therapy
- induced apoptosis
- stem cells
- acute lymphoblastic leukemia
- mesenchymal stem cells
- cell cycle arrest
- randomized controlled trial
- healthcare
- bone marrow
- primary care
- acute myeloid leukemia
- dendritic cells
- endoplasmic reticulum stress
- immune response
- oxidative stress
- signaling pathway
- papillary thyroid
- cell death
- squamous cell carcinoma
- cell proliferation
- hematopoietic stem cell
- pi k akt
- cord blood
- quality improvement
- nk cells