This study will assess whether a quantitative, HER2 assay can accurately and reliably discriminate between responders and non-responders among patients with HER2 IHCI+ metastatic breast cancer who are receiving T-Dxd.
Women and men age > 18 years
Metastatic breast cancer, histologically- confirmed. Any estrogen receptor (ER) status is allowed. ER status will be determined by local laboratory assessment utilizing ASCO/CAP guidelines.
Primary and/or metastatic tumor with 1+ level of expression of HER2 by immunohistochemistry as determined by local laboratory assessment utilizing ASCO/CAP guidelines.
Measurable disease by cross-sectional imaging at the start of treatment. Patients with measurable bone-only disease or active brain metastases are eligible.
Concurrent Her2-overexpressing metastatic breast cancer (as confirmed by a metastatic biopsy with IHC 3+ or IHC 2+ with FISH amplified as per standard ASCO/CAP guidelines)
Abramson Cancer Center at Penn Medicine
Lead sponsor
Translational Breast Cancer Research Consortium
Collaborator
Danaher Inc.
Collaborator