Positive topline results from the DESTINY-Breast02 phase 3 trial of ENHERTU (trastuzumab deruxtecan) versus physician’s choice of treatment showed the trial met the primary endpoint, demonstrating a statistically significant and clinically meaningful improvement in progression-free survival (PFS) in patients with HER2 positive unresectable and/or metastatic breast cancer previously treated with trastuzumab emtansine (T-DM1). The trial also met the key secondary endpoint of improved overall survival.

ENHERTU is a specifically engineered HER2 directed antibody drug conjugate (ADC) being jointly developed and commercialized by Daiichi Sankyo and AstraZeneca.

The trial evaluated a similar later-line patient population as the single-arm DESTINY-Breast01 phase 2 trial, which is the basis for initial approvals in advanced HER2 positive metastatic breast cancer. The safety profile of ENHERTU was consistent with previous phase 3 clinical trials with no new safety concerns identified.

Interstitial lung disease (ILD) rates and severity were consistent with those observed in other metastatic breast cancer trials of ENHERTU, with a low rate of grade 5 ILD observed as determined by an independent adjudication committee.

“The topline results from DESTINY-Breast02 confirm the robust progression-free survival seen in previous trials of ENHERTU and enrich our clinical understanding of the benefit this therapy may offer patients with HER2 positive metastatic breast cancer,” said Ken Takeshita, MD, Global Head, R&D, Daiichi Sankyo.

“As this is the confirmatory trial for our current breast cancer indication in Europe and several other countries, we look forward to sharing these findings with regulatory authorities to add to the body of data for ENHERTU for the treatment of HER2 positive metastatic breast cancer.”

“The DESTINY-Breast02 trial results in this patient population with advanced disease confirm the efficacy and safety profile seen in DESTINY-Breast01 and are consistent with the results seen across our broader clinical program in HER2 positive metastatic breast cancer,” said Susan Galbraith, MBBChir, PhD, Executive Vice President, Oncology R&D, AstraZeneca. “These data further strengthen our confidence in ENHERTU and reinforce its potential to transform patient outcomes across multiple treatment settings.”