CHICAGO –
At a median follow-up of 45.4 months, invasive disease-free survival (IDFS) events occurred in 171 of 2,400 patients (7.1%) who received pertuzumab, compared with 210 of 2,405 patients (8.7%) who received placebo (hazard ratio, 0.81). This 19% reduction in risk of an IDFS event was statistically significant, Gunter von Minckwitz, MD, PhD, reported at the annual meeting of the American Society of Clinical Oncology.
The estimated IDFS rate at 3 years was 94.1% in the pertuzumab arm, and 93.2% in the placebo arm, said Dr. von Minckwitz of the German Breast Group, Neu-Isenburg.
Study subjects were patients with adequately excised HER2-positive, pT1-3 early breast cancer. Patients were randomized to receive adjuvant chemotherapy plus 1 year of either trastuzumab plus pertuzumab, or trastuzumab plus placebo.
In a video interview, Dr. von Minckwitz discusses the study results, including outcomes in node-positive vs. node-negative patients, early overall survival findings, and safety.
“We are using pertuzumab right now in many countries for the neoadjuvant setting,” he said, explaining that existing approvals were granted conditionally in the absence of evidence regarding long-term benefits. “With the APHINITY study ... use of pertuzumab either in the neoadjuvant setting or in the higher-risk adjuvant setting is something that is supported now with evidence.”