Miami Breast Cancer Conference 2021: DESTINY-Breast01 Trial Update on Trastuzumab Deruxtecan-nxki
Posted: Tuesday, March 23, 2021
Trastuzumab deruxtecan-nxki (T-DXd) appears to confer durable responses in patients with HER2-positive metastatic breast cancer, according to Shanu Modi, MD, of the Memorial Sloan Kettering Cancer Center, New York, and colleagues. These updated results from the multicenter phase II DESTINY-Breast01 trial, which were presented during the virtual edition of the 2021 PER’s Miami Breast Cancer Conference (Abstract 58), supported previous findings.
“DESTINY-Breast01…supported regulatory approval [of T-DXd] in the United States, European Union, and Japan,” the investigators commented.
In this trial, a total of 184 patients whose disease progressed on or after treatment with ado-trastuzumab emtansine (T-DM1) were administered 5.4 mg/kg of trastuzumab deruxtecan. The original data cutoff was August 2019, and the updated data cutoff was June 2020.
The median durations of follow-up were 11.1 and 20.5 months at the original and updated cutoffs, respectively. A confirmed objective response rate of 61.4% was observed, with a median duration of response of 20.8 months; a total of 12 patients achieved a complete response. The median duration of progression-free survival was 16.4 months at the original cutoff and 19.4 months at the updated cutoff. At 12 and 18 months, the estimated rates of overall survival were 85% and 74%, respectively. According to the investigators, the preliminary median duration of overall survival was 24.6 months. The safety profile appeared to be congruent with previous reports; a total of three new cases of trastuzumab deruxtecan–related interstitial lung disease were reported after an additional 9 months of follow-up.
“The progression-free survival and immature overall survival results are encouraging; these endpoints will be evaluated in ongoing randomized controlled studies of trastuzumab deruxtecan,” the investigators concluded. “Continued attention to pulmonary symptoms and careful monitoring is warranted.”
Disclosure: Dr. Modi has served as a consultant/speaker for Genentech, Daiichi Sankyo, AstraZeneca, Seattle Genetics, and MacroGenics and has received research support from Genentech, Daiichi Sankyo, AstraZeneca, and Seattle Genetics.
