(HealthDay News) — Patients with advanced breast cancer positive for human epidermal growth factor receptor 2 (HER2) have improved survival when treated with the antibody-drug conjugate trastuzumab emtansine (T-DM1), compared with lapatinib plus capecitabine, according to a study published online Oct. 1 in the New England Journal of Medicine to coincide with presentation at the annual meeting of the European Society for Medical Oncology, held from Sept. 28 to Oct. 2 in Vienna.
Sunil Verma, M.D., from the Sunnybrook Odette Cancer Centre in Toronto, and colleagues randomly assigned 991 patients with advanced HER2-positive breast cancer to T-DM1 or lapatinib plus capecitabine. Patients had previously been treated with trastuzumab and a taxane.
The researchers found that the T-DM1 group had significantly longer median progression-free survival (9.6 versus 6.4 months; hazard ratio for progression or death from any cause, 0.65) and significantly longer median overall survival (30.9 versus 25.1 months; hazard ratio of death from any cause, 0.68). The T-DM1 group had lower rates of grade 3 or 4 adverse events (41 versus 57 percent). This group also had a significantly higher objective response rate and a longer median duration of response.
“In conclusion, our study shows that T-DM1 has therapeutic potential, across a heterogeneous population of patients, for the treatment of advanced, HER2-positive breast cancer that has progressed during or after treatment with trastuzumab and a taxane,” Verma and colleagues conclude.
The study was funded by Hoffmann-La Roche/Genentech, the manufacturer of trastuzumab emtansine; several authors disclosed financial ties to pharmaceutical companies, including Hoffmann-La Roche/Genentech.