The ATEMPT trial was designed to determine if treatment with trastuzumab emtansine (T-DM1) caused less toxicity than paclitaxel plus trastuzumab (TH) and yielded clinically acceptable invasive disease-free survival (iDFS) among patients with stage I human epidermal growth factor receptor 2-positive (HER2+) breast cancer (BC).Patients with stage I centrally confirmed HER2+ BC were randomly assigned 3:1 to T-DM1 or TH and received T-DM1 3.6 mg/kg IV every 3 weeks for 17 cycles or T 80 mg/m2 IV with H once every week × 12 weeks (4 mg/kg load →2 mg/kg), followed by H × 39 weeks (6 mg/kg once every 3 weeks). The co-primary objectives were to compare the incidence of clinically relevant toxicities (CRTs) in patients treated with T-DM1 versus TH and to evaluate iDFS in patients receiving T-DM1.The analysis population includes all 497 patients who initiated protocol therapy (383 T-DM1 and 114 TH). CRTs were experienced by 46% of patients on T-DM1 and 47% of patients on TH (P = .83). The 3-year iDFS for T-DM1 was 97.8% (95% CI, 96.3 to 99.3), which rejected the null hypothesis (P < .0001). Serially collected patient-reported outcomes indicated that patients treated with T-DM1 had less neuropathy and alopecia and better work productivity compared with patients on TH.Among patients with stage I HER2+ BC, one year of adjuvant T-DM1 was associated with excellent 3-year iDFS, but was not associated with fewer CRT compared with TH.
Sara M Tolaney, Nabihah Tayob, Chau Dang, Denise A Yardley, Steven J Isakoff, Vicente Valero, Meredith Faggen, Therese Mulvey, Ron Bose, Jiani Hu, Douglas Weckstein, Antonio C Wolff, Katherine Reeder-Hayes, Hope S Rugo, Bhuvaneswari Ramaswamy, Dan Zuckerman, Lowell Hart, Vijayakrishna K Gadi, Michael Constantine, Kit Cheng, Frederick Briccetti, Bryan Schneider, Audrey Merrill Garrett, Kelly Marcom, Kathy Albain, Patricia DeFusco, Nadine Tung, Blair Ardman, Rita Nanda, Rachel C Jankowitz, Mothaffar Rimawi, Vandana Abramson, Paula R Pohlmann, Catherine Van Poznak, Andres Forero-Torres, Minetta Liu, Kathryn Ruddy, Yue Zheng, Shoshana M Rosenberg, Richard D Gelber, Lorenzo Trippa, William Barry, Michelle DeMeo, Harold Burstein, Ann Partridge, Eric P Winer, Ian Krop