Cetuximab treatment to deplete CAR-37 T cells via tEGFR. (A) Flow cytometry dot plots of CD3⁺EGFR⁺ cells in peripheral blood at the indicated time points. Patients 4 and 5 who experienced bone marrow aplasia at day 27 after CAR-37 therapy were treated with cetuximab on day 28 (patient 5) or day 35 (patient 4) to deplete their CAR-37 T cells (indicated by the arrows). On day 35 (patient 5) or day 43 (patient 4), the patients were treated with transplant conditioning chemotherapy and underwent a HSCT (indicated by the dashed line). The post-HSCT flow plots are also shown. (B) The percentage of CD3⁺EGFR⁺ cells in peripheral blood (left axis, bar graphs) in comparison with the VCN, reported as copies per microgram of DNA, detected by PCR in peripheral blood (right y-axis, line graphs) at the indicated time points is shown. Arrows indicate the timing of cetuximab treatment. The dashed line indicates the timing of the transplant conditioning treatment as shown in panel A.