CAR density influences antitumoral efficacy of BCMA CAR T cells and correlates with clinical outcome
Paula Rodriguez-Marquez 1 , Maria E Calleja-Cervantes 1 2 , Guillermo Serrano 2 , Aina Oliver-Caldes 3 , Maria L Palacios-Berraquero 4 , Angel Martin-Mallo 1 , Cristina Calviño 4 , Marta Español-Rego 5 , Candela Ceballos 6 , Teresa Lozano 7 , Patxi San Martin-Uriz 1 , Amaia Vilas-Zornoza 1 8 , Saray Rodriguez-Diaz 1 , Rebeca Martinez-Turrillas 1 8 , Patricia Jauregui 4 , Diego Alignani 9 , Maria C Viguria 6 , Margarita Redondo 6 , Mariona Pascal 5 , Beatriz Martin-Antonio 3 , Manel Juan 5 10 , Alvaro Urbano-Ispizua 3 , Paula Rodriguez-Otero 4 , Ana Alfonso-Pierola 4 8 , Bruno Paiva 1 8 9 , Juan J Lasarte 7 , Susana Inoges 4 8 11 , Ascension Lopez-Diaz de Cerio 4 8 11 , Jesus San-Miguel 1 4 8 12 , Carlos Fernandez de Larrea 3 , Mikel Hernaez 2 8 13 , Juan R Rodriguez-Madoz 1 8 , Felipe Prosper 1 4 8 12
Identification of new markers associated with long-term efficacy in patients treated with CAR T cells is a current medical need, particularly in diseases such as multiple myeloma. In this study, we address the impact of CAR density on the functionality of BCMA CAR T cells.
Functional and transcriptional studies demonstrate that CAR T cells with high expression of the CAR construct show an increased tonic signaling with up-regulation of exhaustion markers and increased in vitro cytotoxicity but a decrease in in vivo BM infiltration.
Characterization of gene regulatory networks using scRNA-seq identified regulons associated to activation and exhaustion up-regulated in CARHigh T cells, providing mechanistic insights behind differential functionality of these cells. Last, we demonstrate that patients treated with CAR T cell products enriched in CARHigh T cells show a significantly worse clinical response in several hematological malignancies.
In summary, our work demonstrates that CAR density plays an important role in CAR T activity with notable impact on clinical response.