APHINITY Trial Update: Adjuvant Pertuzumab-Based Therapy in Early HER2-Positive Breast Cancer
Posted: Friday, May 14, 2021
The addition of pertuzumab to adjuvant trastuzumab plus chemotherapy showed no significant benefit to the overall survival of patients with HER2-positive early-stage breast cancer, based on a planned second interim analysis of the randomized phase III APHINITY trial published in the Journal of Clinical Oncology. Martine Piccart, MD, PhD, of the Institut Jules Bordet and L’Université Libre de Bruxelles, Belgium, and colleagues reported that the benefits of using adjuvant pertuzumab and trastuzumab for patients with node-positive disease were confirmed with 6-year follow-up, although continued follow-up of patients to assess an overall survival benefit is planned for 2022.
“The longer-term magnitude of benefit of adding pertuzumab to standard adjuvant therapy may not depend upon hormone receptor status of the primary tumor. At this time, there is no evidence to justify the routine use of dual anti-HER2 treatment for patients with node-negative early breast cancer,” the authors noted.
A total of 4,805 patients with node-positive or high-risk node-negative early breast cancer were randomly assigned (1:1) to either 1 year of pertuzumab or placebo in addition to standard adjuvant chemotherapy plus trastuzumab. The median follow-up was 76 months.
Interim analysis of overall survival comparing pertuzumab versus placebo did not reach statistical significance (P = .17, hazard ratio = 0.85). The 6-year overall survival was 95% (125 deaths, 5.2%) vs 94% (147 deaths, 6.1%) in the pertuzumab and placebo groups, respectively (hazard ratio = 0.72). The 6-year invasive disease–free survival, based on 508 events, was 91% and 88%, respectively (hazard ratio = 1.02). A 6-year invasive disease–free survival benefit was seen in the node-positive group (88% and 83%, respectively), whereas the node-negative group reaped no significant benefit (95% for both groups).
No cardiac safety issues were identified. Study limitations included the reliance on nodal status alone to show possible benefit from the addition of pertuzumab.
Disclosure: For full disclosures of the study authors, visit ascopubs.org.