Pertuzumab, Trastuzumab, and Aromatase Inhibition for HR-Positive/HER2-Positive Breast Cancer

Final analysis results from the PERTAIN trial

According to final analysis results from the PERTAIN trial, the progression-free survival (PFS) benefit of adding pertuzumab to trastuzumab, and an aromatase inhibitor with or without chemotherapy, was maintained among patients with hormone-receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-positive breast cancer.

Primary analysis of PERTAIN, showed that adding pertuzumab to trastuzumab and an aromatase inhibitor with or without chemotherapy significantly improved PFS in patients with previously untreated HR-positive/HER2-positive metastatic or locally advanced breast cancer.

This study included 258 patients who were randomized on a 1-to-1 basis to receive either pertuzumab plus trastuzumab every 3 weeks plus an aromatase inhibitor (anastrozole orletrozole), or trastuzumab plus an aromatase inhibitor. Induction chemotherapy was only provided per the investigator’s discretion.

The final analysis includes >6 years of median follow-up. Results demonstrated that in the pertuzumab arm, the median PFS was 20.6 months versus 15.8 in the control arm (stratified hazard ratio [HR], 0.67; P = .006). The median overall survival (OS) was 60.2 in the pertuzumab arm and 57.2 months in the control arm (stratified HR, 1.05; P = .78).

The treatment effect of pertuzumab was potentially enhanced in patients who did not receive induction chemotherapy vs those who did receive chemotherapy (26.6 vs. 12.5 months, respectively). Any-grade adverse events occurred in 122 patients in both arms (96.1% in the pertuzumab arm vs. 98.4% in the control arm). Grade ≥ 3 adverse events occurred in 72 patients in the pertuzumab arm (56.7%) and 51 patients in the control arm (41.1%). Serious adverse events were recorded in 46 patients in the pertuzumab arm (36.2%) and 28 in the control arm (22.6%).

Based on these results, Grazia Arpino, MD, PhD, University of Naples Frederico II, Naples, Italy, and colleagues concluded the PFS benefit of pertuzumab was maintained and the OS was similar between arms at final analysis.

Dr Arpino et al added, “Adding pertuzumab may enhance activity in patients who do not require first-line chemotherapy for [metastatic or locally advanced breast cancer] …These data provide additional evidence of the role of first-line pertuzumab and trastuzumab in HER2-positive [metastatic or locally advanced breast cancer].”

Source:

Arpino G, Rodríguez J, Ferrero J-M, et al. Pertuzumab, trastuzumab, and an aromatase inhibitor for HER2-positive and hormone receptor–positive metastatic or locally advanced breast cancer: PERTAIN final analysis. Clinical Cancer Research. Published online March 16, 2023. doi:10.1158/1078-0432.CCR-22-1092