Key Takeaways From the RELIEVE Study of T-DXd in Real-World mBC

Paolo Tarantino, MD, an advanced research fellow in the breast oncology program at Dana-Farber Cancer Institute, discusses what to know about the real-world findings from the RELIEVE study which were presented at the 2023 San Antonio Breast Cancer Symposium.

In the study, investigators evaluated real-world patients with advanced breast cancer (aBC) who had received trastuzumab deruxtecan (T-DXd; Enhertu). Valuable data on the efficacy of T-DXd in patients whose HER2 expression status switched during treatment was presented at the meeting, highlighting how testing for HER2 status with a liquid biopsy assay predict the clinical activity of fam-trastuzumab deruxtecan-nxki (Enhertu) more accurately in patients with metastatic breast vs using a standard immunohistochemistry assay.

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0:09 | I think what community oncologists should take away from RELIEVE, from this real-world study, is that T-DXd is effective and it's safe for patients outside of clinical trials, because we knew of course, in clinical trials, the rate of ILD cardiotoxicity is low, but it's always important to kind of take that and see what happens in our patients, and patients that are different from those included in trials. They may have diabetes, they may have prior ILD and will have drugs, and I think it's reassuring to see that we did not find extreme toxicities or concerning toxicities. That's the main takeaway. T-DXd is a very effective strategy and even in clinical trials, has shown to be safe.

0:54 | Outside of that, I think it's important also to note that you can offer this treatment strategy among patients that have changes in HER2 status, but we need to collect more data there to understand the implication of changes in their status. Still, if a patient has got different scores in time, maybe the primary tumor being HER2-0 to zero, the metastasis being HER2-low, I think T-DXd still is a treatment strategy that should be thought of just because it has shown to improve overall survival. We want our patients to have available every treatment option that could help them. So once again, our study predicts T-DXd was active. It seemed more active in patients with stable HER2-low disease than HER2-positive, but I think we need to learn more about this evolution of HER2-expression.