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Development and Evaluation of an Optimal Human Single-Chain Variable Fragment-Derived BCMA-Targeted CAR T Cell Vector

Eric L Smith, Mette Staehr, Reed Masakayan, Ishan J Tatake, Terence J Purdon, Xiuyan Wang, Pei Wang, Hong Liu, Yiyang Xu, Sarah C Garrett-Thomson, Steven C Almo, Isabelle Riviere, Cheng Liu, Renier J Brentjens

Mol Ther. 2018 Jun 6;26(6):1447-1456.

PMID: 29678657

Abstract:

B cell maturation antigen (BCMA) has recently been identified as an important multiple myeloma (MM)-specific target for chimeric antigen receptor (CAR) T cell therapy. In CAR T cell therapy targeting CD19 for lymphoma, host immune anti-murine CAR responses limited the efficacy of repeat dosing and possibly long-term persistence. This clinically relevant concern can be addressed by generating a CAR incorporating a human single-chain variable fragment (scFv). We screened a human B cell-derived scFv phage display library and identified a panel of BCMA-specific clones from which human CARs were engineered. Despite a narrow range of affinity for BCMA, dramatic differences in CAR T cell expansion were observed between unique scFvs in a repeat antigen stimulation assay. These results were confirmed by screening in a MM xenograft model, where only the top preforming CARs from the repeat antigen stimulation assay eradicated disease and prolonged survival. The results of this screening identified a highly effective CAR T cell therapy with properties, including rapid in vivo expansion (>10,000-fold, day 6), eradication of large tumor burden, and durable protection to tumor re-challenge. We generated a bicistronic construct including a second-generation CAR and a truncated-epithelial growth factor receptor marker. CAR T cell vectors stemming from this work are under clinical investigation.

Chemicals Related in the Paper:

Catalog Number Product Name Structure CAS Number Price
IAR4248878 BCMA human BCMA human Price
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