Safety outcomes with first-line treatment of Enhertu (fam-trastuzumab deruxtecan-nxki; T-DXd) plus Perjeta (pertuzumab) is comparable with that of standard of care treatment options in patients with HER2-positive advanced or metastatic breast cancer. These findings were derived from the phase 3 DESTINY-Breast09 trial which were shared at the 2025 ASCO Annual Meeting.
The multicenter, open-label DESTINY-Breast09 study evaluated treatment with Enhertu plus placebo, Enhertu plus Perjeta, or a taxane in combination with Herceptin and Perjeta (the standard of care), in which, the Enhertu plus Perjeta regimen improved key survival end points in this patient population.
To further discuss these outcomes, Dr. Sara M. Tolaney, a medical oncologist and senior physician at Dana-Farber Cancer Institute, sat down for an interview with CURE. During the interview, she described the safety profile of this HER2-positive breast cancer treatment, highlighting side effects to be aware of.
Tolaney is also chief of the Division of Breast Oncology and director of the Susan F. Smith Center for Women’s Cancers, as well as an associate professor of medicine at Harvard Medical School, all located in Boston, Massachusetts.
Transcript:
The transcript has been edited for clarity and conciseness.
When patients get the current standard of care — a taxane plus Herceptin and Perjeta — some of the common side effects that we see with this treatment include things like diarrhea, neutropenia, anemia, and neuropathy. Those are typical side effects with the taxane, and treatment with Perjeta can add some diarrhea as well.
With Enhertu and Perjeta, we see nausea and some neutropenia. [Additionally], approximately 12% of patients developed what we call interstitial lung disease, which is some inflammation within the lungs, and that is something that does need to get monitored. If it develops to a point where someone has symptoms, then we actually discontinue the drug.
You can see that there’s slightly different toxicity profiles, but overall, when compared in this trial, the rate of significant toxicity — what we call grade 3 or 3 adverse events or serious adverse events — is the same between the two arms, which is reassuring.
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