This designation is for its use in combination with pertuzumab as a first-line treatment for adult patients with unresectable or metastatic HER2-positive breast cancer.
The FDA’s decision was based on the results from the DESTINY-Breast09 Phase III trial, a global, multicentre trial assessing the efficacy and safety of Enhertu (5.4mg/kg) alone or with pertuzumab versus standard THP (taxane, trastuzumab, and pertuzumab) in first-line treatment for HER2-positive metastatic breast cancer.
Patients were randomised into 1:1:1 ratio to receive Enhertu monotherapy with a pertuzumab placebo, Enhertu with pertuzumab, or THP, with stratification by prior treatment, hormone receptor status, and phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) mutation status.
The primary endpoint is progression-free survival (PFS) evaluated by blinded independent central review in both the Enhertu monotherapy and combination arms.
Daiichi Sankyo R&D global head Ken Takeshita said: “This breakthrough therapy designation provides further recognition of the potential benefit of Enhertu in combination with pertuzumab in the first-line setting of HER2-positive metastatic breast cancer.
“If approved, Enhertu will continue to redefine the treatment of metastatic breast cancer, as these latest results from DESTINY-Breast09 demonstrate a median progression-free survival of more than three years when using ENHERTU plus pertuzumab in this disease setting, which is an improvement over the current standard of care that has been in place for more than a decade.”
Enhertu’s latest BTD marks its ninth overall and fifth specifically related to metastatic breast cancer treatments.
Additionally, four other BTDs were awarded for various other cancers where overexpression or mutation of the HER2 gene plays a critical role.
These 13 oncology-related BTD within Daiichi Sankyo’s portfolio underscore the potential impact that Enhertu could have on treating multiple forms of aggressive cancers linked to the HER2 protein.