Subgroup analyses of the DESTINY-Breast03 study evaluating trastuzumab deruxtecan as second-line therapy in HER2-positive metastatic breast cancer.
Volkmar Müller, MD, Prof Dr: We were all impressed with the data from the DESTINY-Breast03 trial. I saw it with colleagues in a hotel room in Lima, Peru, 20 people, and we applauded after seeing the data. We had many thoughts about the results, they’re impressive. Did you have comments or thoughts on the results when you saw them?
Tiffany A. Traina, MD: I would agree, the data were impressive. This patient population had seen trastuzumab and a taxane as an eligibility requirement, and about 60% had seen prior pertuzumab. Some of the patients in the DESTINY-Breast03 trial had stable treated brain metastases, and we heard how impressive the progression-free survival impact was. That forest plot showed every subgroup favored and derived benefit from trastuzumab deruxtecan over T-DM1 [trastuzumab emtansine]. This applied to hormone receptor-positive or hormone receptor-negative tumors, to patients who saw pertuzumab prior, those who were naïve to pertuzumab, and to patients who had or lacked visceral disease. About half of these patients were treated in the second-line setting, and the other half were third line and later, both of which favored benefit from [trastuzumab] deruxtecan. That subset of patients with stable treated brain metastases, which accounted for about 115 patients on study, they also had a significant benefit from [trastuzumab] deruxtecan, the hazard ratio was 0.37. Every subgroup examined favored [trastuzumab] deruxtecan.
Transcript edited for clarity.