What the trial was testing
The DESTINY-Breast04 enrolled 557 patients with breast cancer. The study was sponsored by Daiichi Sankyo and tracked outcomes across the full group of patients who matched the trial's eligibility profile.
It was a large trial designed to confirm whether the treatment works well enough for wider use. Trials at this stage are designed to produce evidence regulators and physicians can act on — not just observations to follow up later.
What the results showed
Roughly doubled the time before cancer progression in HER2-low breast cancer.
New England Journal of Medicine · 2022 · NCT03734029
These findings — that median time before cancer progression on trastuzumab deruxtecan vs. chemotherapy in HER2-low metastatic breast cancer — were published in the New England Journal of Medicine and represent the headline result of the study.
Researchers tracked outcomes across 557 patients enrolled in the trial. The result was consistent enough across the group that the team felt confident reporting it.
What this means for patients
For patients with breast cancer, this result changes the calculus on what to ask their care team about. Whether it changes day-to-day care depends on factors like disease subtype, prior treatments, and where the patient is in their care journey.
What you can do now
Trastuzumab deruxtecan (Enhertu) is FDA-approved for HER2-low metastatic breast cancer that has been previously treated with chemotherapy and available now. It is given as an IV infusion every three weeks. A serious lung side effect is a known risk and requires careful monitoring. Ask your oncologist about HER2-low testing and eligibility.
Eligibility for the treatments mentioned above depends on specific test results and clinical history. Bring this summary, the trial name, and your most recent labs or pathology report to your next visit.
Open breast cancer trials
Clinical Trial of Avasopasem in Patients With Metastatic Hormone Receptor Positive Breast Cancer With Progression on a CDK 4/6 Inhibitor and Hormonal Therapy
This study aims to evaluate the safety of avasopasem in combination with CDK 4/6 inhibitor and hormonal therapy in women with metastatic hormone receptor positive breast cancer, and to see if the addition of avasopasem improves the effectiveness of a CDK 4/6 inhibitor and hormonal therapy.
Breast cancEr, FITness and ExeRcise for Heart Health: The BE-FITTER Study
The chemotherapy medications used for breast cancer treatment are important for achieving a cure, but a potential side effect is that they can cause a decline in functional capacity (reduced exercise tolerance and impaired physical function) and increase the risk of cardiovascular disease. The risks of decreased functional capacity and cardiovascular disease are highest in breast cancer survivors as they grow older. The factors causing the decline in functional capacity are not well understood, however they may be related to a reduction in cardiac function (e.g. decreased pumping ability of the heart) or skeletal muscle function (reduced muscle blood flow and oxygenation). Exercise training is used for other populations at risk for cardiovascular disease (such as cardiac rehabilitation), but is not routinely offered to breast cancer survivors. Therefore this research study wants to test whether exercise training can improve heart and muscle health, and increase functional capacity in up to 60 older breast cancer survivors aged \>60 years old who previously received chemotherapy drugs that can affect the heart. The purpose of this study is to compare two rehabilitation approaches: a 12-week structured exercise training program or a 12-week stretching-yoga program. The investigators want to compare whether these programs can improve functional capacity, and heart and skeletal muscle function. To do this, some of the participants in this study will be randomly enrolled in the structured exercise training program and others will be randomly enrolled in the stretching-yoga program.