Posted: Thursday, December 21, 2023
Findings from the phase III TROPION-Breast01 trial, presented at the 2023 San Antonio Breast Cancer Symposium (SABCS; Abstract GS02-01), suggest that treatment with the antibody-drug conjugate datopotamab deruxtecan (Dato-DXd) may result in improved survival outcomes vs chemotherapy in some patients with hormone receptor (HR)-positive, HER2-negative breast cancer. The safety profile and quality-of-life outcomes associated with the combination treatment were also “favorable,” according to the study authors.
“These data support Dato-DXd as a potential new therapeutic option for patients with inoperable or metastatic HR-positive, HER2-negative breast cancer who have received one to two prior lines of chemotherapy,” concluded Aditya Bardia, MD, MPH, of Massachusetts General Hospital Cancer Center, Boston, and colleagues.
The study included 732 patients who were randomly assigned to receive Dato-DXd (n = 365) or the investigator’s choice of chemotherapy (n = 367). At the data cutoff, 93 patients in the Dato-DXd group and 39 patients in the chemotherapy group were still receiving treatment.
Progression-free survival was significantly longer with the combination treatment (hazard ratio = 0.63, 95% confidence interval = 0.52–0.76) regardless of the number of prior lines of chemotherapy, prior use of endocrine therapy, and presence of brain metastases. Median time to the first subsequent therapy was longer with the combination (8.2 vs 5.0 months), and fewer patients in the combination group had received subsequent therapy after discontinuation of the study (53% vs 67%). The Dato-DXd group reported fewer than half the number of grade 3 or higher treatment-related adverse events than did the chemotherapy cohort.
All patients had inoperable or metastatic HR-positive, HER2-negative breast cancer, had undergone one to two prior lines of chemotherapy, and were unsuitable candidates for endocrine therapy after having previously experienced disease progression while receiving treatment. The investigator’s choice of chemotherapy included eribulin, vinorelbine, capecitabine, and gemcitabine.
Disclosure: For full disclosures of the study authors, visit atgproductions.net.
2023 San Antonio Breast Cancer Symposium