In Vivo Human-Derived Xenograft Tumor Studies in Mice

All animal research and veterinary care were performed under the Guide for the Care and Use of Laboratory Animals under approved protocols of the Takeda Boston Institutional Animal Care and Use Committee in a facility accredited by the Association for Assessment and Accreditation of Laboratory Animal Care International (AAALAC). A suspension of the human colorectal cancer model cell line was subcutaneously injected into the flank of female NOD SCID Gamma (NSG) mice at 2.0 × 10⁶ cells/mouse. The projected tumor volume at the initial date is approximately 150 mm³. The animals were sorted into treatment groups (n = 3) and were given a single intravenous administration of CAR-T positive cells at a dose of 1.0 × 10⁶ CAR positive T cells/100 μL/mouse. Mice were sacrificed at designated time points (1 h, day 1, 3, 7, 10, 14, 21, and 28) after the administration, then blood and tumor samples were harvested. Tumor volume and body weight were measured before the sample collection. Samples were frozen and stored under − 80 °C until sample analysis.