Eye on Pharma: Genentech Granted Priority Review for Pertuzumab Plus Trastuzumab

Genentech, a member of the Roche Group, has announced that it has been granted FDA priority review for its supplemental biologics license application (sBLA) for pertuzumab (Perjeta), together with trastuzumab (Herceptin) and chemotherapy, for adjuvant treatment of HER2-positive early breast cancer (EBC). The FDA is expected to issue a regulatory decision by January 28, 2018.

The sBLA relies on data from the phase 3 APHINITY study. The international, randomized, double-blind, placebo-controlled, 2-arm study evaluated the efficacy and safety of trastuzumab and chemotherapy combined with either pertuzumab or placebo, as adjuvant treatment in 4805 patients who had operable HER2-positive EBC. The study’s primary endpoint was invasive disease-free survival (iDFS), which the study defined as the time that a patient lives without the return of invasive breast cancer at any site and without death from any cause after adjuvant treatment.

The rate of iDFS at 3 years was 94.1% in the pertuzumab, trastuzumab, and chemotherapy arm, and 93.2% in the trastuzumab, chemotherapy, and placebo arm. Estimated iDFS at 4 years, based upon data available to date, was 92.3% and 90.6% in the 2 arms, respectively.

The fact that the FDA has granted a priority review of the drug—a review designation available only to medicines that the agency has determined to have the potential to provide significant improvements in treatment, prevention, or diagnosis of a disease—suggests that the agency may see the APHINITY study’s results as more impressive than investors did. When results of the trial were announced in June, Roche’s stock sank by 5.2% on concerns that the high cost of pertuzumab therapy relative to the improvements that it offered would keep the drug from being widely used in low-risk patients.

An analysis published in the Journal of Clinical Oncology, which assessed cost effectiveness of pertuzumab plus trastuzumab in the earlier CLEOPATRA study (a study that assessed pertuzumab and trastuzumab in metastatic breast cancer), concluded that use of the combination was unlikely to be cost effective, at least in treating metastatic breast cancer, in the United Sates.

If Roche is successful in securing FDA approval, use of pertuzumab together with trastuzumab (also developed by Roche) could help the drug maker hold on to some of its oncology market dominance in the face of growing competition from anticancer biosimilars. Additionally, some analysts have said that the fact that pertuzumab would extend the duration of a patient’s treatment will contribute to higher sales overall sales for Roche.