APHINITY six-year analysis presented at SABCS 2019
Every year in December, the San Antonio Breast Cancer Symposium (SABCS) brings together researchers and physicians from around the world to present and discuss the latest findings in breast cancer research.
On 11 December 2019, Dr Martine Piccart presented data from a second interim overall survival (OS) analysis of the phase III APHINITY study, evaluating the combination of Perjeta® (pertuzumab), Herceptin® (trastuzumab) and chemotherapy (the Perjeta-based regimen) as an adjuvant (after surgery) treatment for patients with HER2-positive early breast cancer (eBC).
Data from the six-year analysis of the APHINITY trial strengthen evidence of the clinical benefit of adding pertuzumab to adjuvant trastuzumab plus chemotherapy in patients with HER2-positive early breast cancer.
The aim of APHINITY is to investigate a new drug called pertuzumab, which also acts on the HER2 marker, but in a different way than trastuzumab, and to combine it with the current standard of care (chemotherapy and trastuzumab). This dual anti-HER2 therapy uses drugs that work in a complementary way and may improve treatment of this specific breast cancer subtype. The hope is that this strategy can increase the chances of cure among patients with HER2-positive breast cancer.
In 2017 the APHINITY trial demonstrated a 19% risk reduction, which at that time translated into a modest benefit in invasive disease-free survival (iDFS) at three years for the overall population in the APHINITY study. The benefit appeared more pronounced in patients at higher risk of relapse, such as those with lymph node-positive disease. Based on these results, pertuzumab in combination with trastuzumab and chemotherapy was approved for the post-surgery treatment of patients with high-risk HER2-positive eBC.
The second APHINITY analysis shows that, after six years of follow-up, although there were fewer deaths in the pertuzumab arm, the overall survival data was not statistically significant. Longer follow-up is needed to see the survival benefit of adding pertuzumab to standard treatment. At this six-year analysis, the greatest improvement in iDFS remains in patients at high risk of recurrence, such as those with lymph node-positive disease, with a 28% risk reduction of recurrence or death, corresponding to an absolute iDFS benefit of 4.5%.
Although fewer deaths were seen among the patients who received treatment with pertuzumab, the data are still immature and have not shown definitive improvement in overall survival. A next interim analysis is scheduled to take place in 2022.