Adjuvant Trastuzumab Emtansine Versus Paclitaxel in Combination With Trastuzumab for Stage I HER2-Positive Breast Cancer (ATEMPT): A Randomized Clinical Trial

Abstract

PURPOSE 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). METHODS 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. RESULTS 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. CONCLUSION 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.

Benefits of neoadjuvant therapy compared with adjuvant chemotherapy for the survival of patients with HER2-positive breast cancer: A retrospective cohort study at FUSCC

“…The authors of the Adjuvant Paclitaxel and Trastuzumab (APT) Trial suggested that administering adjuvant paclitaxel and trastuzumab to patients with stage I Her2-positive breast cancer represented a de-escalating therapy that preserved quality of life and achieved excellent outcomes for these patients [ 14 , 15 ]. Adjuvant Trastuzumab Emtansine Versus Paclitaxel in Combination with Trastuzumab for Stage I HER2-Positive Breast Cancer (ATEMPT) showed that among patients with stage I HER2-positive breast cancer, one year of adjuvant T-DM1 was associated with excellent 3-year invasive disease-free survival (iDFS) compared with paclitaxel plus trastuzumab [ 16 , 17 ].…”

Efficacy of adjuvant trastuzumab in women with HER2-positive T1a or bN0M0 breast cancer: a population-based cohort study

“…A recent randomized phase II ATTEMPT trial compared the combination of trastuzumab and weekly paclitaxel to antibody–drug conjugate trastuzumab emtansine (T-DM1) in women with stage I HER2 positive breast cancer. The rate of clinically relevant toxicity was similar between the 2 groups (47% vs. 46%) 23 . It is not known if a non-chemotherapy HER2 directed treatment can be used without compromising the outcome of patients with small node negative HER2 positive breast cancer.…”

HER2+ Breast Cancer Escalation and De-Escalation Trial Design: Potential Role of Intrinsic Subtyping

“…In order to further improve these clinical results from APT trial, the ATEMPT trial compared adjuvant T-DM1 and paclitaxel plus trastuzumab in patients with stage I HER2+ BC. TDM-1 was associated with excellent 3-year iDFS, but not with fewer clinically relevant toxicity [59]. Further translational results are anticipated.…”