At the six-year mark, 90.6% of patients in the Perjeta cohort have not had breast cancer return, compared to 87.8% in the placebo arm. This comes to an absolute benefit of 2.8%.
Roche, along with the Breast International Group (BIG), Institut Jules Bordet Clinical Trials Support Unit (IJB-CTSU) and Frontier Science Foundation (FS) announced results from a second interim overall survival (OS) analysis of the Phase III APHINITY study. This trial evaluated the combination of Perjeta (pertuzumab), Herceptin (trastuzumab) and chemotherapy as a post-surgery (adjuvant) therapy for patients with HER2-positive early breast cancer (eBC).
The latest analysis was performed after a median follow-up of about 74 months, compared to about 45 months for the 2017 primary analysis. This also included new descriptive iDFS and cardiac safety data.
“The goal of adjuvant treatment is to give each person with early breast cancer the best chance of a cure,” said Levi Garraway, chief medical officer and head of Global Product Development for Roche. “These new data with longer follow-up show the continued effect of the Perjeta-based regimen and an increased invasive disease-free survival benefit.”
The Perjeta-based treatment reduced the risk of breast cancer recurrence of death by 24% compared to Herceptin, chemotherapy and placebo. At the six-year mark, 90.6% of patients in the Perjeta cohort have not had breast cancer return, compared to 87.8% in the placebo arm. This comes to an absolute benefit of 2.8%.
The APHINITY study is an international, Phase III, randomized, double-blind, placebo-controlled, two-arm study looking at 4,805 patients with operable HER2-positive eBC. The primary endpoint is iDFS, which was defined as the time a patient lives without return of invasive breast cancer at any site, or death from any cause after adjuvant treatment. The secondary endpoints included cardiac and overall safety, OS, disease-free survival and health-related quality of life. The study will continue tracking participants for 10 years.
Perjeta is a monoclonal antibody approved for use before and after surgery with Herceptin (trastuzumab) and chemotherapy (docetaxel) in patients with HER2-positive breast cancer that has metastasized and who have not received anti-HER2 therapy or chemotherapy for metastatic breast cancer. It targets the HER2 receptor, which is found on many normal cells and in high amounts in cancer cells in HER2-positive cancers. It prevents the HER2 receptor from pairing with other HER receptors on the cells’ surface. The binding of Perjeta to HER2 is thought to signal the immune system to destroy the cancer cells. Together, Perjeta and Herceptin are believed to complement each other because they both bind to the HER2 receptor, but at different locations.
“These results demonstrate the importance of longer follow-up of APHINITY and further confirm the Perjeta-based regimen as the standard of care for people with HER2-positive early breast cancer at high risk of recurrence, such as those with lymph node-positive disease,” said Martine Piccard, co-founder of BIG and scientific director at the Institute Jules Bordet.
The strongest effect observed, similar to that seen in the primary analysis, was in patients at high risk of recurrence, for example, in patients with lymph node (LN)-positive disease. These patients had a 28% decrease in the risk of recurrence of death in the Perjeta-based arm compared to the Herceptin, chemotherapy and placebo cohort. The treatment effect of the Perjeta-based therapy is observed regardless of the patient’s hormone receptor (HR) status.
