Trastuzumab emtansine (T-DM1) versus trastuzumab in Chinese patients with residual invasive disease after neoadjuvant chemotherapy and HER2-targeted therapy for HER2-positive breast cancer in the phase 3 KATHERINE study.
Breast Cancer Res Treat 2021;
187:759-768. [PMID:
33860389 DOI:
10.1007/s10549-021-06166-y]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 02/24/2021] [Indexed: 10/21/2022]
Abstract
PURPOSE
In the KATHERINE study (NCT01772472), patients with HER2-positive early breast cancer (EBC) and residual invasive disease after neoadjuvant chemotherapy plus HER2-targeted therapy who were treated with adjuvant trastuzumab emtansine (T-DM1) had a 50% reduction in the risk of an invasive disease-free survival (IDFS) event compared to patients treated with adjuvant trastuzumab. In metastatic disease, T-DM1 has resulted in higher rates of thrombocytopenia in Asian versus non-Asian patients. Here, we report safety and efficacy in Chinese patients from KATHERINE.
METHODS
Patients with HER2-positive EBC and residual invasive disease after taxane- and trastuzumab-containing neoadjuvant chemotherapy followed by surgery were randomized 1:1 to 14 cycles of adjuvant T-DM1 or trastuzumab. The primary endpoint was time to an IDFS event.
RESULTS
Among Chinese patients (T-DM1 n = 51, trastuzumab n = 50), T-DM1 treatment resulted in a 43% reduction in risk of an IDFS event compared to trastuzumab (HR = 0.57; 95% CI 0.25-1.31), with similar results for secondary endpoints. As in the global population, Chinese patients receiving T-DM1 versus trastuzumab had more grade ≥ 3 adverse events (AEs; 39.2% versus 4.1%) and AEs leading to treatment discontinuation (27.5% versus 0%). The most common grade ≥ 3 AE with T-DM1 was thrombocytopenia (21.6%), a frequency higher than the frequency in the global population (5.7%). Grade ≥ 3 hemorrhage was reported in 1 patient (T-DM1 arm).
CONCLUSIONS
In the KATHERINE study, T-DM1 demonstrated increased efficacy compared to trastuzumab in Chinese patients. Consistent with previous data in Asian patients, T-DM1 was associated with more grade ≥ 3 AEs, and AEs leading to discontinuation, which was driven by an increase in thrombocytopenia.
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