Trastuzumab Emtansine Improves Survival for Patients With HER2-Positive Early Breast Cancer
Updated results from the phase 3 KATHERINE trial demonstrated that trastuzumab emtansine (T-DM1) improved survival compared to trastuzumab among previously treated patients with human epidermal growth factor receptor 2 (HER2)-positive early breast cancer.
“Patients with [HER2]-positive early breast cancer with residual invasive disease after neoadjuvant systemic therapy have a high risk of recurrence and death,” stated Charles Geyer, MD, UPMC Hillman Cancer Center, Pittsburgh, Pennsylvania, and coauthors. “Primary analysis of KATHERINE…showed that the risk of invasive breast cancer or death was 50% lower with adjuvant [T-DM1] than with trastuzumab alone.”
In this open-label study, patients with HER2-positive early breast cancer with residual invasive disease who previously received neoadjuvant systemic treatment with taxane-based chemotherapy and trastuzumab were randomized to receive either T-DM1 or trastuzumab for 14 cycles. Primary end points included invasive disease-free survival (iDFS), overall survival (OS), and safety.
At a median follow-up of 8.4 years, the 7-year iDFS rate was 80.8% in the T-DM1 arm and 67.1% in the trastuzumab arm (hazard ratio [HR], 0.54). T-DM1 led to a significantly lower risk of death compared to trastuzumab (unstratified HR, 0.66; 95% confidence interval [CI], 0.51 to 0.87; P = .003). The 7-year OS rate was 89.1% in the T-DM1 arm and 84.4% in the trastuzumab arm. Grade ≥3 adverse events were reported in 26.1% of patients in the T-DM1 arm and 15.7% of patients in the trastuzumab arm.
“As compared with trastuzumab, T-DM1 improved overall survival with sustained improvement in invasive disease-free survival among patients with HER2-positive early breast cancer with residual invasive disease after neoadjuvant therapy,” concluded Dr Geyer et al.
Source:
Geyer CE, Untch M, Huang CS, et al. Survival with trastuzumab emtansine in residual HER2-positive breast cancer. N Engl J Med. Published online: January 15, 2025. doi: 10.1056/NEJMoa2406070
