Phase III APHINITY study showed adjuvant (after surgery) treatment with the combination of Perjeta (pertuzumab), Herceptin (trastuzumab) and chemotherapy significantly reduced the risk of breast cancer recurrence or death - Roche

Roche, the Breast International Group (BIG), Breast European Adjuvant Study Team (BrEAST) and Frontier Science Foundation (FS) announced at ASCO 2017 that the Phase III APHINITY study showed adjuvant (after surgery) treatment with the combination of Perjeta (pertuzumab), Herceptin (trastuzumab) and chemotherapy (the Perjeta-based regimen) significantly reduced the risk of breast cancer recurrence or death (invasive disease-free survival; iDFS) by 19% in people with HER2-positive early breast cancer (eBC) compared to Herceptin and chemotherapy alone (HR=0.81; 95% CI 0.66-1.00, p=0.045). At three years, 94.1% of people treated with the Perjeta-based regimen did not have their breast cancer return compared to 93.2% treated with Herceptin and chemotherapy.

The safety profile of the Perjeta-based regimen was consistent with that seen in previous studies, with a low incidence of cardiac events and no new safety signals. Based on data available at the time of the primary analysis, an estimate of iDFS at four years showed that 92.3% of people treated with the Perjeta-based regimen did not have their breast cancer return compared to 90.6% treated with Herceptin and chemotherapy, suggesting that further analyses with longer follow-up will be important to provide additional insights on these treatments.

At the time of the primary analysis, with median follow-up of 45.4 months, the reduction in risk of invasive breast cancer recurrence with the Perjeta-based regimen was greatest in people with lymph node-positive (HR=0.77; 95% CI 0.62-0.96, p=0.019) or hormone receptor-negative disease (HR=0.76; 95% CI 0.56-1.04, p=0.085). At three years, among people with node-positive disease, 92.0% of people treated with the Perjeta-based regimen did not have their breast cancer return compared to 90.2% treated with Herceptin and chemotherapy, and iDFS rates in the hormone receptor-negative disease subgroup were 92.8% in the Perjeta-based arm and 91.2% in the Herceptin and chemotherapy arm. The number of events in both treatment arms was low in people with node-negative disease, where no benefit with the Perjeta-based regimen was detected at this time.

See- "Adjuvant Pertuzumab and Trastuzumab in Early HER2-Positive Breast Cancer"- Gunter von Minckwitz, M.D., Marion Procter, Ph.D., Evandro de Azambuja, M.D., et al, for the APHINITY Steering Committee and Investigators June 5, 2017DOI: 10.1056/NEJMoa1703643.

Comment: APHINITY's target was to show that adding Perjeta would significantly improve invasive disease-free survival rates in women with early HER2-positive breast cancer.The results presented at ASCO showed the addition of Perjeta to Herceptin and chemotherapy significantly reduced the risk of breast cancer recurrence or death (invasive disease-free survival, or iDFS) by 19% in people with HER2-positive early breast cancer compared to Herceptin and chemotherapy alone. At three years according to Roche, 94.1% of people treated with the Perjeta-based regimen did not have their breast cancer return compared to 93.2% treated with Herceptin and chemotherapy. However the benefit was much lower than anticipated. .