Faculty, Staff and Student Publications
Publication Date
2-3-2025
Journal
Clinical Cancer Research
Abstract
PURPOSE: Datopotamab deruxtecan (Dato-DXd) is a humanized anti-trophoblast cell-surface antigen-2 (TROP2) IgG1 mAb linked to a potent topoisomerase I inhibitor payload (DXd). Dato-DXd has already shown antitumor activity in breast cancer; however, the determinants of response, including the importance of TROP2 expression, remain unclear. We tested the activity of Dato-DXd in a panel of breast cancer patient-derived xenografts (BCX) varying in TROP2 expression.
EXPERIMENTAL DESIGN: The antitumor activity of Dato-DXd and isotype-control-DXd (IgG-DXd) was assessed against 11 BCXs varying in TROP2 expression, 10 representing tumors postneoadjuvant chemotherapy. Pharmacodynamic effects were assessed at 24 and 72 hours. The effects of TROP2 expression on Dato-DXd activity was assessed in vitro and in vivo using viral overexpression in BCX-derived cell lines.
RESULTS: Models differed in their sensitivity to both Dato-DXd and IgG-DXd. Dato-DXd (10 mg/kg) led to objective response in 4 (36%) models and statistically significant prolongation of event-free survival in 8 (73%) models, whereas IgG-DXd (10 mg/kg) led to response in 1 (9%) and prolonged event-free survival in 3 (27%) models. TROP2 RNA and protein were significantly higher in Dato-DXd-sensitive models. In isogenic cell lines derived from Dato-DXd-resistant BCXs, overexpression of TROP2 conferred Dato-DXd antitumor activity in vitro and in vivo. Dato-DXd increased γH2AX and phospho-KAP1 in the two Dato-DXd-sensitive BCXs but not in a Dato-DXd-resistant BCX. In Dato-DXd-sensitive models, antitumor activity was enhanced in combination with a PARP inhibitor, olaparib.
CONCLUSIONS: Dato-DXd is active in breast cancer models. Dato-DXd has TROP2-dependent and -independent mediators of activity; however, high TROP2 expression enhances Dato-DXd antitumor activity.
Keywords
Humans, Animals, Antigens, Neoplasm, Breast Neoplasms, Female, Xenograft Model Antitumor Assays, Cell Adhesion Molecules, Mice, Immunoconjugates, Biomarkers, Tumor, Camptothecin, Cell Line, Tumor, Antibodies, Monoclonal, Humanized
DOI
10.1158/1078-0432.CCR-24-1948
PMID
39585341
PMCID
PMC11788653
PubMedCentral® Posted Date
11-25-2024
PubMedCentral® Full Text Version
Post-print
Published Open-Access
yes
Included in
Bioinformatics Commons, Biomedical Informatics Commons, Medical Sciences Commons, Oncology Commons