Two studies published in October report noteworthy advances in the use of CRISPR-Cas9 gene editing technology to refine allogeneic CAR T-cell therapy. One study describes what the researchers say is, to their knowledge, the first use of Sleeping Beauty (SB) transposons with CRISPR-Cas9 to efficiently produce allogeneic TCR-disrupted CD-19 CAR T cells. The other reports the results of a first-in-human clinical trial of CRISPR-engineered allogeneic CD19 CAR T cells in six children with relapsed or refractory CD19-positive B-cell acute lymphoblastic leukemia.
A research team in Belgium described optimizing and validating a non-viral system based on SB transposon–mediated expression of CD19-targeted CARs and targeted inactivation of endogenous TCR genes using CRISPR-Cas9 ribonucleoparticles to engineer off-the-shelf human CAR T cells free of endogenous TCR.
“The resulting CAR T cells are highly functional against CD19-expressing target cells and CD19+ tumor-bearing mice for tumor eradication with reduced TCR alloreactivity and GvHD development,” write senior authors Marinee K. CHuah and Thierry VandenDriessche of the Free University in Brussels and colleagues in a paper published in Molecular Therapy.
Researchers at the Great Ormond Street Hospital for Children NHS Trust in London, UK, describe employing CRISPR-Cas9 editing and linked CAR expression to devise an investigational T-cell therapy that they then tested in a single-center phase I trial. The work built on a previous approach in which T cells modified with transcription-activator-like effector nucleases were used to disrupt endogenous TCR alpha chain and CD52 genes in HLA-mismatched allogeneic CAR19 T cells.
Four of the six patients infused with the investigational T cells “exhibited cell expansion, achieved flow cytometric remission, and then proceeded to receive allogeneic stem cell transplantation.” The phase I study “provides encouraging early-stage evidence of [the] feasibility, safety, and therapeutic potential [of] CRISPR-Cas9 editing,” write senior author Waseem Qasim and colleagues In a paper published in Science Translational Medicine.
- Ottaviano G, Georgiadis C, Gkazi SA, et al. Phase 1 clinical trial of CRISPR-engineered CAR19 universal T cells for treatment of children with refractory B cell leukemia. Sci Transl Med. 2022;14(668):eabq3010. doi:10.1126/scitranslmed.abq3010
- Tipanee J, Samara-Kuko E, Gevaert T, Chuah MK, VandenDriessche T. Universal allogeneic CAR T cells engineered with Sleeping Beauty transposons and CRISPR-CAS9 for cancer immunotherapy. Mol Ther. 2022;30(10):3155-3175. doi:10.1016/j.ymthe.2022.06.006