Eight-Year Data Show Pertuzumab Regimen Reduces Risk of Recurrence, Death for Patients with HER2-positive Breast Cancer

A pertuzumab (Perjeta; Roche)-based regimen reduces the risk of disease recurrence for patients with HER2-positive early breast cancer, according to 8-year data from the APHINITY study, announced by Roche in a press release. The greatest benefit of this treatment was seen in patients with lymph node-positive disease who are at high risk of occurrence and have the greatest need for more efficacious treatments.

Updated data from the APHINITY study in HER2-positive early breast cancer were announced by Roche, the Breast International Group, Institut Jules Bordet Clinical Trials Support Unit and Frontier Science Foundation. Full findings of the study were presented at the European Society for Medical Oncology (ESMO) Virtual Plenary on July 14.

“The 8-year APHINITY results show the great progress made in treating this aggressive form of early breast cancer,” said Levi Garraway, MD, PhD, Roche’s chief medical officer and head of Global Product Development in a statement. “HER2-positive breast cancers are more likely than other subtypes to recur following surgery, so targeted treatment is critical to provide the best chance for a cure.”

The APHINITY (Adjuvant Pertuzumab and Herceptin IN Initial TherapY in Breast Cancer) study evaluates the efficacy and safety of pertuzumab, trastuzumab (Herceptin), and chemotherapy, compared to trastuzumab and chemotherapy, as adjuvant treatment. The study includes 4804 people with operable HER2-positive early breast cancer. Data at 8.4 years median follow up were presented at ESMO.

The results showed the continued benefit of the combination of pertuzumab, trastuzumab, and the trastuzumab-based regimen of chemotherapy, compared to trastuzumab, chemotherapy, and placebo, when given as adjuvant intravenous treatment for people with lymph node-positive, HER2-positive early breast cancer. The results showed a 28% reduction in the risk of recurrence or death for patients with lymph node-positive disease, corresponding to an absolute benefit of 4.9% at 8 years (invasive disease-free survival [iDFS], hazard ratio [HR]=0.72, 95% confidence interval [CI] 0.60-0.87).

The third interim of overall survival (OS) analysis of the APHINITY study was also conducted at a median follow up of 8.4 years. Updated results on iDFS and safety were included.

The results showed outcomes consistent with prior analyses.

After 8 years, fewer deaths were observed with the pertuzumab-based regimen (168 [7.0%] versus 202 [8.4%] [HR=0.83; 95% CI: 0.68-1.02]); however, Roche notes that OS data remain immature and statistical significance has not yet been reached.

The pertuzumab-based regimen also continued to reduce the risk of breast cancer recurrence or death by 23% in the overall study population, compared to trastuzumab, chemotherapy, and placebo (iDFS, HR=0.77, 95% CI 0.66-0.91).

Of people who receive post-surgery treatment with the pertuzumab-based regimen, 88.4% remained disease-free. This proportion was greater than for people treated with trastuzumab, chemotherapy and placebo, of whom 85.8% remained disease-free.

People with high risk of cancer recurrence, primarily those with LN-positive disease, saw the greatest benefit, a 28% reduction in the risk of recurrence or death with the pertuzumab-based regimen (HR=0.72; 95% CI 0.60-0.87, showing an absolute benefit of 4.9%: 86.1% versus 81.2%).

The effect of the pertuzumab-based regimen was seen regardless of hormone receptor status, consistent with prior analysis. There was a 25% reduction in the risk of recurrence or death in people with hormone receptor-positive disease, compared with an 18% reduction in people with hormone-receptor negative disease (hormone receptor-positive disease: HR=0.75; 95% CI 0.61-0.92 and hormone receptor-negative disease: HR=0.82; 95% CI 0.64-1.06).

The safety profile was consistent with previous studies, including cardiac safety. No new or unexpected safety signals were identified, according to the release.

“These updated APHINITY data showed further reduction in the risk of cancer returning or death with a pertuzumab-based regimen in patients with LN-positive, HER2-positive early breast cancer, regardless of hormone receptor status,” said prof. Sibylle Loibl, chair of the German Breast Group (GBG) and the chief executive officer of the GBG Forschungs GmbH, and APHINITY study chair. “The trend towards a survival benefit was influenced by the LN-positive cohort and additional follow-up is very important to determine possible survival benefit and long-term safety of this regimen.”

The pertuzumab-based regimen is approved for treatment of patients with early breast cancer who are at a high risk of recurrence in more than 100 countries, including the United States, the European Union, and China. Multiple international treatment guidelines recognize the regimen and recommend it as a standard of care for the post-surgery treatment of patients with HER2-positive early breast cancer at high risk of recurrence, including those from American Society of Clinical Oncology (ASCO), ESMO, the National Comprehensive Cancer Network (NCCN) and St Gallen International Breast Cancer Conference.

More than 500,000 people who have HER2-positive breast cancer and are at high risk of recurrence have received the pertuzumab-based regimen so far.

Reference

Eight-year data from APHINITY study show Roche’s Perjeta-based regimen continues to reduce the risk of disease returning for people with HER2-positive early breast cancer [press release]. Basel, Switzerland: F. Hoffmann-La Roche Ltd; July 14, 2022. https://www.roche.com/media/releases/med-cor-2022-07-14b. Accessed July 15, 2022.