
ENHERTU® (fam-trastuzumab deruxtecan-nxki), in combination with pertuzumab, has received Breakthrough Therapy Designation (BTD) from the U.S. Food and Drug Administration (FDA) for the first-line treatment of adults with unresectable or metastatic HER2-positive breast cancer.
ENHERTU is a specially designed HER2-directed DXd antibody-drug conjugate (ADC), discovered by Daiichi Sankyo (TSE: 4568) and jointly developed and commercialized by Daiichi Sankyo and AstraZeneca .
The FDA’s BTD is intended to expedite the development and regulatory review of promising therapies for serious conditions that address an unmet medical need. To qualify, a therapy must show preliminary clinical evidence of substantial improvement over existing treatments on clinically meaningful endpoints.
This latest designation is supported by data from the DESTINY-Breast09 Phase 3 trial, which were presented in a special late-breaking oral session at the 2025 American Society of Clinical Oncology (#ASCO25) Annual Meeting.
“The Breakthrough Therapy Designation underscores the potential of ENHERTU in combination with pertuzumab to transform first-line treatment for patients with HER2-positive metastatic breast cancer,” said Ken Takeshita, MD, Global Head of R&D at Daiichi Sankyo. “If approved, this combination could set a new standard, as DESTINY-Breast09 demonstrated a median progression-free survival exceeding three years—surpassing the current standard of care that has remained unchanged for over a decade.”
With this latest recognition, ENHERTU has now been granted nine Breakthrough Therapy Designations, including five for breast cancer:
Second-line HER2-positive metastatic breast cancer
Later-line HER2-positive metastatic breast cancer
Later-line HER2-low metastatic breast cancer
HER2-low or HER2-ultralow metastatic breast cancer
First-line HER2-positive metastatic breast cancer (latest designation)
In addition to breast cancer, ENHERTU has received four BTDs for other HER2-expressing or HER2-mutant cancers, including:
HER2-positive (IHC 3+) metastatic solid tumors
HER2-positive metastatic colorectal cancer
HER2 (ERBB2) mutant metastatic non-small cell lung cancer (NSCLC)
HER2-positive metastatic gastric cancer
This new designation marks the 13th Breakthrough Therapy Designation granted across Daiichi Sankyo’s oncology portfolio.