Study
| Phase 3, multicenter, randomized, controlled trial (KATHERINE) |
| HER2-positive early breast cancer with residual invasive cancer after neoadjuvant therapy |
| T-DM1 vs. trastuzumab (14 cycles every 3 weeks) |
Efficacy
| 7-yr IDFS: 80.8% vs. 67.1% (T-DM1 vs. trastuzumab) (HR: 0.54 [0.44-0.66]) |
| Distant recurrence: 14.7% vs. 21.5% |
| CNS recurrence (first invasive-disease event): 7.0% vs. 5.1% |
| CNS recurrence (subsequent): 0.5% vs. 2.6% |
| 7-yr OS: 89.1% vs. 84.4% (HR: 0.66 [0.51-0.87], P=0.003) |
Safety
| Grade ≥3 AEs: 26.1% vs. 15.7% (T-DM1 vs. trastuzumab) |
| Serious AEs: 12.7% vs. 8.1% |
| Cardiac and other toxic effects: Rare in both groups |
N Engl J Med 2025;392:249-257
http://doi.org/10.1056/NEJMoa2406070
Reviewed by Ulas D. Bayraktar, MD on Jan 24, 2025
