T-DXd Shows Benefits in Phase 3 Early Breast Cancer Study
T-DXd plus THP led to significant improvements in pathologic complete response in patients with early-stage, HER2+ breast cancer, according to DESTINY-Breast11 data.
Medical illustration of breast cancer
Fam-trastuzumab deruxtecan-nxki (T-DXd; Enhertu) followed by paclitaxel, trastuzumab (Herceptin), and pertuzumab (Perjeta; THP) led to a statistically significant and clinically meaningful improvement in pathologic complete response (pCR) vs the standard of care when used in the neoadjuvant setting for patients with high-risk, locally advanced, HER2-positive, early-stage breast cancer, according to high-level results from the phase 3 DESTINY-Breast11 study (NCT05113251).1
This marks the first phase 3 study to demonstrate benefits of T-DXd in early breast cancer, and achieving a pCR in early-stage HER2-positive breast cancer is associated with better long-term outcomes.
“The clinically meaningful improvement in pathologic complete response and the safety data seen in DESTINY-Breast11 highlight the potential of [T-DXd] to challenge the current standard of care in early-stage HER2-positive breast cancer. [T-DXd] is already an important treatment option in the metastatic setting, and these data have the potential to allow this medicine to move into early stages of disease where cure is possible,” said Susan Galbraith, executive vice president of oncology hematology research and development at AztraZeneca, in a press release.
Data for the secondary end point of event-free survival (EFS) were not mature at the time of this analysis; however, there was an early positive trend for EFS in the T-DXd arm vs the standard of care of doxorubicin and cyclophosphamide followed by THP.
Data from DESTINY-Breast11 will be presented at an upcoming medical meeting and shared with regulatory authorities.
About DESTINY-Breast11
DESTINY-Breast11 is a randomized, open-label, phase 3 study comparing T-DXd vs doxorubicin and cyclophosphamide followed by THP before surgery in patients with high-risk, HER2-positive, early-stage breast cancer.2 A third arm evaluating T-DXd alone was initially included in the study; however, this arm was closed following recommendations from an independent committee.1
The primary end point is pCR, and secondary end points include EFS, invasive disease-free survival, and overall survival.2
Patients were enrolled at 146 global sites. To be eligible, patients were required to be at least 18 years of age, have histologically documented HER2-positive early breast cancer, have an ECOG performance status of 0 or 1, and have adequate organ and bone marrow function.
About T-DXd
T-DXd is a HER2-directed antibody-drug conjugate and currently approved in over 75 countries for the treatment of unresectable or metastatic HER2-positive breast cancer that has been treated with at least 1 anti-HER2-based regimen. Its approval was supported by results from the DESTINY-Breast03 study (NCT03529110).1
In April 2025, findings from DESTINY-Breast09 (NCT04784715) showed that T-DXd plus pertuzumab led to a highly statistically significant and clinically meaningful improvement in progression-free survival vs THP for the treatment of patients with first-line, HER2-positive, metastatic breast cancer.3
