- Data from the largest biomarker analysis to date show that immune markers predict benefit of adjuvant pertuzumab in early-stage breast cancer.
- Findings add to mounting evidence for an immune-mediated mechanism of action that may help shape future clinical trials in this setting.
Why this matters
- The phase 3 APHINITY study demonstrated a modest improvement in invasive DFS (iDFS) with the addition of adjuvant pertuzumab to trastuzumab+chemotherapy.
- Analysis of the APHINITY trial of patients with HER2+ breast cancer to investigate genomic correlates of response to adjuvant trastuzumab and pertuzumab.
- 1023 patient samples were evaluated.
- Funding: Genentech; Pfizer.
- The following were associated with inferior prognosis:
- PI3K/PTEN/AKT pathway mutations: P=.04.
- Amplification of MYC: P=.00.
- Amplification of ZNF703: P=.02.
- The following were associated with favorable prognosis:
- TOP2A copy number amplifications, independent of treatment: P=.00.
- Higher levels of TILs: P=.001.
- HER2 copy number ≥6: P=.01.
- PI3K/PTEN/AKT alterations, MYC, ZNF703, and TOP2A copy number amplifications were not predictive of pertuzumab benefit.
- High levels of TILs and T-cell-related genes were predictive of greater pertuzumab benefit.
- Further analyses of immune-associated biomarkers are required.