KATHERINE — Trastuzumab Emtansine vs Trastuzumab as Adjuvant Therapy for Residual Invasive HER2-Positive Breast Cancer After Neoadjuvant Therapy

Phase 3 · 2019 · Breast Cancer

Design

Randomized 1:1 to adjuvant trastuzumab emtansine (T-DM1) vs trastuzumab in patients with residual invasive disease after neoadjuvant therapy.

Population

HER2-positive early breast cancer with residual invasive disease after neoadjuvant chemotherapy plus HER2-targeted therapy.

Primary Endpoint

invasive disease-free survival (iDFS)

Key Result

3-yr iDFS 88.3% vs 77.0% (HR 0.50); ~50% reduction in recurrence risk, with OS benefit in later follow-up (HR 0.66).

Guideline Impact

NCCN category 1 for residual HER2+ disease after neoadjuvant therapy