DESTINY-Breast09 — Trastuzumab deruxtecan with or without pertuzumab versus taxane, trastuzumab, and pertuzumab in first-line HER2-positive metastatic breast cancer (DESTINY-Breast09)

Phase 3 · Breast Cancer

Population

Previously untreated HER2-positive metastatic breast cancer.

Primary Endpoint

Progression-free survival by blinded independent central review

Rationale

Trastuzumab deruxtecan transformed later-line HER2-positive breast cancer. DESTINY-Breast09 tests whether it can displace the long-standing first-line THP standard, potentially bringing the antibody-drug conjugate to the very front of the treatment course.

What It Could Change

Could establish trastuzumab deruxtecan as the first-line standard for HER2-positive metastatic breast cancer, replacing the taxane-trastuzumab-pertuzumab regimen.