Key clinical point: According to the PERTAIN trial’s final analysis, the progression-free survival (PFS) benefit associated with the addition of pertuzumab to trastuzumab+aromatase inhibitor (AI) persisted even after >6 years of follow-up in patients with human epidermal growth factor receptor 2-positive (HER2+)/hormone receptor-positive (HR+) metastatic breast cancer (BC).
Major finding: After a median follow-up of >70 months, a >2-year PFS benefit was observed in the pertuzumab+trastuzumab+AI vs trastuzumab+AI treatment group (20.6 vs 15.8 months; stratified hazard ratio 0.67; P = .006). No new safety signals were identified.
Study details: Findings are from the phase 2 PERTAIN study including 258 postmenopausal patients with previously untreated HER2+/HR+ metastatic or locally advanced BC who were randomly assigned to receive pertuzumab+trastuzumab+AI or trastuzumab+AI.
Disclosures: This study was supported by F. Hoffmann-La Roche Ltd. Some authors declared serving as advisors or on speaker’s bureau for or receiving research grants, travel, or accommodation expenses from several sources. Four authors declared being employees of or owning stocks in F. Hoffmann-La Roche.
Source: Arpino G et al. Pertuzumab, trastuzumab, and an aromatase inhibitor for HER2-positive and hormone receptor-positive metastatic/locally advanced breast cancer: PERTAIN final analysis. Clin Cancer Res. 2023 (Jan 30). Doi: 10.1158/1078-0432.CCR-22-1092