Daiichi Sankyo has submitted a supplemental New Drug Application (sNDA) to Japan’s Ministry of Health, Labour and Welfare (MHLW) for ENHERTU (Trastuzumab Deruxtecan) in combination with Pertuzumab for the treatment of patients with HER2 positive unresectable or recurrent breast cancer.

ENHERTU is a specifically engineered HER2 directed DXd Antibody Drug Conjugate (ADC) discovered by Daiichi Sankyo and being developed and commercialised by Daiichi Sankyo in Japan.

HER2 targeted therapies have improved outcomes in HER2 positive metastatic breast cancer; however, prognosis remains poor with most patients experiencing disease progression within two years of first-line treatment with Taxane, Trastuzumab and Pertuzumab (THP), which has been the standard of care for more than a decade.

The sNDA is based on data from the DESTINY-Breast09 phase-3 trial presented during a special late-breaking oral session at the 2025 American Society of Clinical Oncology (#ASCO25) Annual Meeting.

“In DESTINY-Breast09, ENHERTU plus Pertuzumab demonstrated a median progression-free survival of more than three years, which represents an impressive improvement over the current standard of care. Following the recent approval of ENHERTU in Japan for the treatment of HER2 low or HER2 ultralow metastatic breast cancer, this new submission of ENHERTU plus Pertuzumab for the first-line treatment of patients with HER2 positive disease underscores the commitment of Daiichi Sankyo to bring ENHERTU to as many patients as possible in this region across certain subtypes of metastatic breast cancer,” said Yuki Abe, PhD, Head—R&D Division, Japan, and Head—Research, Daiichi Sankyo.