KATHERINE
A Randomized, Multicenter, Open-Label Phase III Study to Evaluate the Efficacy and Safety of Trastuzumab Emtansine Versus Trastuzumab as Adjuvant Therapy for Patients With HER2-Positive Primary Breast Cancer Who Have Residual Tumor Present Pathologically in the Breast or Axillary Lymph Nodes Following Preoperative Therapy
Phase 3N = 1,486NCT01772472
- Population
- HER2-positive early breast cancer with residual invasive disease in the breast or axilla after neoadjuvant taxane (with or without anthracycline) and trastuzumab
- Design
- Phase 3 open-label randomised trial of adjuvant trastuzumab emtansine versus trastuzumab for 14 cycles. Primary endpoint: invasive disease-free survival.
- Primary endpoint
- iDFS
- Arms
- Trastuzumab (control, n = 743): Adjuvant trastuzumab for 14 cycles
- Trastuzumab emtansine (T-DM1) (experimental, n = 743): Adjuvant trastuzumab emtansine for 14 cycles
- People
- von Minckwitz G
iDFSHR 0.50 (95% CI 0.39–0.64)Δ 36-month iDFS+11.3 pointsiDFSHR 0.54 (95% CI 0.44–0.66)Δ 84-month iDFS+13.7 pointsOSHR 0.66 (95% CI 0.51–0.87)Δ 84-month OS+4.7 points
Show the numbers
| Endpoint | Analysis | Trastuzumab emtansine (T-DM1) | Trastuzumab | Effect |
|---|---|---|---|---|
| iDFSAll randomised patients (1486) | interimvon 2019 | 88.3% at 3 y | 77% at 3 y | HR 0.50 (95% CI 0.39–0.64)P<0.001Interim analysis. Invasive disease or death occurred in 91 patients (12.2%) in the T-DM1 group and 165 (22.2%) in the trastuzumab group. Distant recurrence as the first invasive-disease event: 10.5% with T-DM1 and 15.9% with trastuzumab. |
| iDFSAnalysis population not stated in the abstract (1486 randomised in the trial) | finalmedian follow-up 8.4 yearsGeyer 2025 | 80.8% at 7 y | 67.1% at 7 y | HR 0.54 (95% CI 0.44–0.66)Prespecified final analysis of invasive disease-free survival; unstratified hazard ratio; difference of 13.7 percentage points at seven years. |
| OSAnalysis population not stated in the abstract (1486 randomised in the trial) | interimGeyer 2025 | 89.1% at 7 y | 84.4% at 7 y | HR 0.66 (95% CI 0.51–0.87)P=0.003Second interim analysis of overall survival; unstratified hazard ratio; difference of 4.7 percentage points at seven years. The abstract states the 8.4-year median follow-up with the iDFS result and does not repeat it for overall survival, so it is not recorded here. |
| Endpoint | Analysis | Trastuzumab emtansine (T-DM1) | Trastuzumab | Effect |
|---|---|---|---|---|
| iDFSAll randomised patients (1486) | interimvon 2019 | 88.3% at 3 y | 77% at 3 y | HR 0.50 (95% CI 0.39–0.64)P<0.001Interim analysis. Invasive disease or death occurred in 91 patients (12.2%) in the T-DM1 group and 165 (22.2%) in the trastuzumab group. Distant recurrence as the first invasive-disease event: 10.5% with T-DM1 and 15.9% with trastuzumab. |
| iDFSAnalysis population not stated in the abstract (1486 randomised in the trial) | finalmedian follow-up 8.4 yearsGeyer 2025 | 80.8% at 7 y | 67.1% at 7 y | HR 0.54 (95% CI 0.44–0.66)Prespecified final analysis of invasive disease-free survival; unstratified hazard ratio; difference of 13.7 percentage points at seven years. |
| OSAnalysis population not stated in the abstract (1486 randomised in the trial) | interimGeyer 2025 | 89.1% at 7 y | 84.4% at 7 y | HR 0.66 (95% CI 0.51–0.87)P=0.003Second interim analysis of overall survival; unstratified hazard ratio; difference of 4.7 percentage points at seven years. The abstract states the 8.4-year median follow-up with the iDFS result and does not repeat it for overall survival, so it is not recorded here. |
Data table
| Endpoint | HR | 95% CI |
|---|---|---|
| iDFS | 0.5 | 0.39–0.64 |
| iDFS | 0.54 | 0.44–0.66 |
| OS | 0.66 | 0.51–0.87 |
Appears in
Sources
von Minckwitz G, Huang CS, Mano MS, Loibl S, Mamounas EP, Untch M, et al. Trastuzumab Emtansine for Residual Invasive HER2-Positive Breast Cancer. N Engl J Med. 2019;380(7):617-628.
Geyer CE Jr, Untch M, Huang CS, Mano MS, Mamounas EP, Wolmark N, et al. Survival with Trastuzumab Emtansine in Residual HER2-Positive Breast Cancer. N Engl J Med. 2025;392(3):249-257.