ESMO 2024: DESTINY-Breast12 Supports T-DXd in Patients With HER2-Positive Breast Cancer and Brain Metastases

By: Julia Cipriano, MS
Posted: Wednesday, September 18, 2024

Treatment with the anti-HER2 antibody-drug conjugate fam-trastuzumab deruxtecan-nxki (T-DXd) showed substantial and durable overall and intracranial activity in patients with HER2-positive advanced or metastatic breast cancer and stable or active baseline brain metastases, according to Nancy Lin, MD, of the Dana-Farber Cancer Institute, Boston, and colleagues. These primary results from the multicenter phase IIIb/IV DESTINY-Breast12 trial, which were presented during the European Society for Medical Oncology (ESMO) Congress 2024 (Abstract LBA18) and simultaneously published in the journal Nature Medicine, also revealed no new safety signals.

“These results support the use of the drug going forward in this patient population,” Dr. Lin commented in an institutional press release.

Patients with (n = 263) and without (n = 241) stable or active brain metastases who experienced disease progression on at least one prior anti-HER2–based regimen and received up to two prior therapy regimens in the metastatic setting (had to be tucatinib-naive) were administered 5.4 mg/kg of T-DXd intravenously every 3 weeks. Follow-up data were provided for a median of 15.4 and 16.1 months in these cohorts with central nervous system (CNS) disease progression, respectively.   

The 12-month overall progression-free survival rate was 61.6% in patients with brain metastases and 72.1% in those without. In these cohorts, the overall objective response rates were 51.7% and 62.7%, respectively. The 12-month CNS progression-free survival rate was 58.9% (stable: 57.8%; active: 60.1%), and the CNS objective response rate was 71.7% (stable: 79.2%; active: 62.3%).

Adverse events of grade 3 or higher were reported in 51.0% of patients with brain metastases and 49.0% of those without such disease progression. A total of 16.0% and 12.9% of these cohorts, respectively, had interstitial lung disease/pneumonitis. According to the investigators, in patients with brain metastases, five such events occurred with opportunistic infection.

Disclosure: For full disclosures of the study authors, visit cslide.ctimeetingtech.com.

ESMO Congress 2024

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