HQ Team
June 3, 2025: AstraZeneca and Daiichi Sankyo’s breast cancer drug, Enhertu, has cut the risk of disease progression or death by 44% compared to a taxane, trastuzumab and pertuzumab combination.
Enhertu (trastuzumab deruxtecan) and pertuzumab combination “demonstrated a highly statistically significant and clinically meaningful improvement in progression-free survival,” according to a joint statement.
The treatment is meant to be a first-line treatment for patients with HER2-positive metastatic breast cancer.
People treated with Enhertu plus pertuzumab lived much longer without their cancer worsening — about 40.7 months (almost 3.5 years) — compared to about 20.7 months (less than 2 years) for those on the other arm.
This benefit was observed across all types of patients, regardless of their specific cancer characteristics, assessed by blinded independent central review.
Shrink or disappear
About 85% of patients on Enhertu plus pertuzumab had their tumours shrink or disappear, compared to about 79% on the taxane, trastuzumab and pertuzumab (THP) arm.
Fifty-eight people had their cancer completely disappear with Enhertu plus pertuzumab, compared to 33 in the THP group. The data on overall survival was not complete, but initial results suggest patients on Enhertu plus pertuzumab might live longer than those on THP.
Results were presented at the 2025 American Society of Clinical Oncology Annual Meeting in Chicago.
“Patients with HER2-positive metastatic breast cancer often experience disease progression around two years after initiating standard-of-care first-line treatment,” said Sara Tolaney, MD, MPH, Chief of the Division of Breast Oncology, Dana-Farber Cancer Institute and principal investigator in the trial.
‘First-line standard of care’
“With a median progression-free survival of more than three years, the DESTINY-Breast09 results show trastuzumab deruxtecan combined with pertuzumab has the potential to become a new first-line standard of care for these patients.”
Susan Galbraith, Executive Vice President, Oncology Haematology R&D, AstraZeneca, said the use of Enhertu earlier in the treatment of HER2-positive metastatic breast cancer may represent an important advancement for patients.
The Enhertu combination in the first-line setting substantially increased the amount of time before a patient’s cancer progressed compared to standard of care and nearly doubled the number of patients showing no signs of disease on imaging, she said.
“Establishing a strong therapeutic response as soon as metastatic disease is diagnosed is critical, given that about one in three patients do not receive further treatment after progressing in the first-line setting.”
‘Diagnosis can delay progression’
Ken Takeshita, Global Head, R&D, Daiichi Sankyo, said that initiating treatment with Enhertu in combination with pertuzumab at the time of metastatic diagnosis can delay disease progression.
An additional investigational arm of the trial assessing the monotherapy versus THP remains blinded to patients and investigators and will continue to the final disease progression free survival analysis.
Enhertu is a specifically engineered HER2-directed DXd antibody drug conjugate discovered by Daiichi Sankyo and being jointly developed and commercialised by Daiichi Sankyo and AstraZeneca.
Five years following diagnosis
It is already approved in more than 80 countries as a second-line treatment for patients with HER2-positive breast cancer.
Breast cancer is the second most common cancer and one of the leading causes of cancer-related deaths worldwide. More than two million breast cancer cases were diagnosed in 2022, with more than 665,000 deaths globally.
While survival rates are high for those diagnosed with early breast cancer, only about 30% of patients diagnosed with or who progress to metastatic disease are expected to live five years following diagnosis.
