HER2-Positive Brain Mets Respond to Enhertu
Enhertu (chemical name: fam-trastuzumab-deruxtecan-nxki), also called T-DXd, helped control areas of metastatic HER2-positive breast cancer in the brain, according to results from the DESTINY-Breast12 study presented at ESMO 2024. The results were published at the same time in the journal Nature Medicine.
Key takeaways
Enhertu shrank the spots of metastatic HER2-positive breast cancer in the brain in 71% of women with brain metastases.
Progression-free survival – how long the women lived without the cancer growing – was about 17 months for women with brain metastases who received Enhertu.
About 16% of women with brain metastases in the study developed interstitial lung disease (serious disorders that cause lung inflammation and scarring) from Enhertu treatment.
What this means for you
According to Nancy Lin, MD, the Dana-Farber Cancer Institute scientist who led and presented the research, up to half of people diagnosed with metastatic HER2-positive breast cancer develop brain metastases. People with brain metastases tend to have a worse prognosis than people who don’t have brain metastases.
Treatments such as surgery and stereotactic radiation therapy to the brain can treat brain metastases, but the disease usually grows in the brain and spinal cord (the central nervous system) within six to 12 months of these local treatments.
The results of this study show that Enhertu may be a good treatment option for people with HER2-positive breast cancer that has spread to the brain and has grown during other treatments. If this is your situation, it makes sense to talk to your doctor about Enhertu and ask if it’s right for you.
Why do the study?
Earlier small studies suggested the Enhertu could help treat HER2-positive breast cancer lesions in the brain. The researchers did this larger study to gather more information on the effectiveness and safety of using Enhertu to treat brain metastases.
About the study
The study included 504 women diagnosed with metastatic HER2-positive breast cancer that had grown during previous treatment:
263 women had brain metastases
241 women didn’t have brain metastases
Of the 263 women with brain metastases, 106 had metastases that were growing, which the researchers called active metastases. The other 157 had metastases that weren’t growing, or stable metastases.
Detailed results
The women in the study received Enhertu every three weeks and stayed on the treatment for an average of 12 months.
The researchers followed half the women for more than 15.4 months and half for shorter periods of time.
Among women with brain metastases, 79% of the stable brain metastases and 62% of the active brain metastases responded to Enhertu.
Enhertu shrank the cancer tumors by at least 30% in about 50% of women with brain metastases and 63% of women without brain metastases.
Among women with brain metastases, Enhertu stopped tumors in both the body and the brain from growing for a year:
62% had tumors in the body stay stable for a year
59% had tumors in the brain stay stable for a year
About 20% of the women in the study had side effects from Enhertu. The most common side effects were nausea, fatigue, and constipation.
Interstitial lung disease, a known, serious side effect of Enhertu, was diagnosed in 16% of women (42 women) with brain metastases and 13% of women (31 women) without brain metastases. Overall, nine women in the study died from interstitial lung disease. Four of the women who died were reported to have other lung infections at the same time as interstitial lung disease.
Harbeck, N., et al. Trastuzumab deruxtecan in HER2-positive advanced breast cancer with or without brain metastases: a phase 3b/4 trial. Nat Med (2024).
Lin, N., et al. Trastuzumab deruxtecan (T-DXd) in patients (pts) with HER2+ advanced/metastatic breast cancer (mBC) with or without brain metastases (BM): DESTINYBreast-12 primary results. ESMO 2024. Abstract LBA18.
— Last updated on January 3, 2025 at 7:46 PM