Trastuzumab Deruxtecan Shows Survival Improvement in HER2-positive Metastatic Breast Cancer

Trastuzumab deruxtecan (Enhertu) demonstrated a statistically significant improvement in progression-free survival (PFS) compared with physician’s choice of therapy in patients with HER2-positive unresectable and/or metastatic breast cancer previously treated with trastuzumab emtansine (T-DM1).¹

Results show that the phase 2 DESTINY-Breast02 met its primary end point. The key secondary end point of improvement in overall survival (OS) was also met, according to an announcement by AstraZeneca. The data builds on the efficacy and trastuzumab deruxtecan in patients with HER2-positive breast cancer.

“The top-line 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, Global Head, R&D, Daiichi Sankyo, in a press release. 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.”

DESTINY-Breast02 is a multicenter, randomized, open-label, active-controlled study. In the study, approximately 600 patients with HER2-positive metastatic breast cancer were treated with either trastuzumab deruxtecan or the physician’s choice of capecitabine or lapatinib (Tykerb). Patients were evaluated for the primary end point of PFS by blinded independent review and secondary end points including OS, objective response rate, duration of response, and PFS by investigator assessment.²

Patients were eligible for inclusion in the study if they reached the age of maturity in their country, had pathologically documented unresectable or metastatic and HER2 expression. All patients were required to be previously treated with T-DM1, and have documented radiologic progression, and adequate hematopoietic, renal, and hepatic functions.

The study excluded patients who were previously treated with an antibody-drug conjugate or capecitabine. Patients with controlled or significant cardiovascular disease, history of or current interstitial lung disease/pneumonitis, and active central nervous system metastases were excluded.

The DESTINY-Breast02 is ongoing at 227 study sites across the United States, Europe, Asia, Oceania, and the Middle East. Data from the study will be presented at an upcoming medical meeting, according to AstraZeneca.

“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. These data further strengthen our confidence in Enhertu and reinforce its potential to transform patient outcomes across multiple treatment settings, said Susan Galbraith, Executive Vice President, Oncology R&D, AstraZeneca, in the press release.¹

_REFERENCES:

_{1. Enhertu significantly delayed disease progression in DESTINY-Breast02 Phase III trial vs. physician’s choice of treatment in patients with HER2-positive metastatic breast cancer. News release. August 15, 2022. Accessed August 15, 2022.}

_{2. DS-8201a in pre-treated HER2 breast cancer that cannot be surgically removed or has spread [DESTINY-Breast02]. Clinicatrials.gov. Updated August 12, 2022. Accessed August 15, 2022.}