Regulatory approval

Published by the Food and Drug Administration. Approved

The U.S. Food and Drug Administration granted approval to fam-trastuzumab deruxtecan-nxki, as monotherapy, for the treatment of adult patients with unresectable or metastatic hormone receptor-positive HER2-low (immunohistochemistry 1+ or immunohistochemistry 2+/in situ hybridization-negative) or HER2-ultralow (immunohistochemistry 0 with membrane staining) breast cancer, as determined by an FDA-authorized test, that has progressed on one or more endocrine therapies in the metastatic setting. This indication is based on DESTINY-Breast06, in which HER2-ultralow was defined as membrane staining that was seen in greater than 0 and less than or equal to 10% of tumor cells.

This is written in the approval document as:

ENHERTU is a HER2-directed antibody and topoisomerase inhibitor conjugate indicated, as monotherapy, for the treatment of adult patients with unresectable or metastatic hormone receptor (HR)-positive HER2-low (IHC 1+ or IHC 2+/ISH-) or HER2-ultralow (IHC 0 with membrane staining) breast cancer, as determined by an FDA-authorized test, that has progressed on one or more endocrine therapies in the metastatic setting.

Citation

Daiichi Sankyo. Enhertu (fam-trastuzumab deruxtecan-nxki) [package insert]. U.S. Food and Drug Administration website. https://www.accessdata.fda.gov/drugsatfda_docs/label/2026/761139s041s043lbl.pdf. Revised May 2026. Accessed October 8, 2026.

Therapeutic response

Precision oncology relationships for therapeutic response derived from this regulatory approval.

Organizations
Biomarkers
Cancer types
Therapies
Organizations Biomarkers Cancer types Therapies
FDA (2) ER positive, HER2-low Invasive Breast Carcinoma Trastuzumab deruxtecan
FDA (2) HER2-low, PR positive Invasive Breast Carcinoma Trastuzumab deruxtecan
FDA (2) ER positive, HER2-low, PR positive Invasive Breast Carcinoma Trastuzumab deruxtecan
FDA (2) ER positive, HER2-ultralow Invasive Breast Carcinoma Trastuzumab deruxtecan
FDA (2) HER2-ultralow, PR positive Invasive Breast Carcinoma Trastuzumab deruxtecan
FDA (2) ER positive, HER2-ultralow, PR positive Invasive Breast Carcinoma Trastuzumab deruxtecan

Contributions

Date Contributor Description
2026-10-08 Van Allen lab Initial curation of this indication into moalmanac-db.
2025-01-27 Food and Drug Administration Indication received traditional approval.