FDA grants priority review to breast-cancer therapy pertuzumab

FDA has granted priority review to pertuzumab (Genentech, a member of the Roche Group) in combination with trastuzumbab (Herceptin, Genentech) and docetaxel chemotherapy for certain breast-cancer patients.

The treatment is aimed at patients with HER2-positive metastatic or locally recurrent, unresectable breast cancer who have not received previous treatment or whose disease has relapsed after adjuvant therapy.

FDA confirmed the action date is June 8.

"We have been researching HER2-positive breast cancer for more than 30 years, and we hope an expedited review will help us quickly bring another personalized medicine to people battling this aggressive disease," Hal Barron, MD, chief medical officer and head, Genentech Global Product Development, said in a company press release.

The pertuzumab application is based on results from the pivotal phase 3 CLEOPATRA study. The study demonstrated a 6.1-month improvement in median progression-free survival (PFS) for people who received a pertuzumab-based regimen (pertuzumab combined with Herceptin and docetaxel chemotherapy) compared to those who received Herceptin and chemotherapy alone (median PFS 18.5 vs 12.4 months). People who received the combination also experienced a 38% reduction in the risk of their disease worsening or death (HR=0.62; P<.0001), according to independent review.

Adverse events (AEs) were consistent with those seen in previous studies of pertuzumab and Herceptin, either in combination or alone. Rates of Grade 3 or higher AEs with more than 2% difference between arms were observed for neutropenia, febrile neutropenia, and diarrhea with 48.9%, 13.8%, and 7.9% in the pertuzumab, Herceptin, and chemotherapy arm compared with 45.8%, 7.6%, and 5% in the Herceptin plus chemotherapy arm, respectively.

The pertuzumab-based regimen was not associated with a higher incidence of cardiac AEs or left ventricular dysfunction compared with Herceptin and chemotherapy. Left ventricular dysfunction occurred in 8.3% of people in the Herceptin and chemotherapy arm and 4.4% of people in the pertuzumab, Herceptin, and chemotherapy arm.

Pertuzumab is a humanized monoclonal antibody being studied in early and advanced stages of HER2-positive breast cancer and advanced HER2-positive gastric cancer. The HER2 dimerization inhibitor is unique in that it is designed specifically to prevent the HER2 receptor from pairing (dimerizing) with other HER receptors (EGFR/HER1, HER3, and HER4), a process that is believed to play a critical role in the growth and formation of several different cancer types.

By preventing receptor pairing, pertuzumab is thought to block cell signaling, which may inhibit cancer cell growth or lead to the death of the cancer cell. Binding of pertuzumab to HER2 may also signal the body's immune system to destroy the cancer cells.