Summary of the Number of Participants With at Least One Adverse Event, Severity Determined According to National Cancer Institute Common Terminology Criteria for Adverse Events, Version 4.0 (NCI CTCAE v4.0), Over the Course of the Entire Study

Arm A: Pertuzumab IV + Trastuzumab IV + Chemotherapy

Participants received 8 cycles of investigator's choice of neoadjuvant chemotherapy. This included either: 1) 4 cycles of dose-dense doxorubicin plus cyclophosphamide (ddAC) once every 2 weeks (Q2W) (given with granulocyte colony-stimulating factor \[G-CSF\] support as needed according to local guidelines) followed by paclitaxel QW for 12 weeks; or 2) 4 cycles of doxorubicin plus cyclophosphamide (AC) once every 3 weeks (Q3W) followed by docetaxel Q3W for 4 cycles. Pertuzumab and trastuzumab were given intravenously (IV) for 4 cycles Q3W concurrently with the taxane component of chemotherapy. After completing their neoadjuvant therapy, participants underwent surgery. Thereafter, participants received an additional 14 cycles of pertuzumab IV and trastuzumab IV for a total of 18 cycles.

Arm B: Pertuzumab and Trastuzumab FDC SC + Chemotherapy

Participants received 8 cycles of investigator's choice of neoadjuvant chemotherapy. This included either: 1) 4 cycles of ddAC Q2W (given with G-CSF support as needed according to local guidelines) followed by paclitaxel once every week (QW) for 12 weeks; or 2) 4 cycles of AC Q3W followed by docetaxel Q3W for 4 cycles. The fixed-dose combination (FDC) of pertuzumab and trastuzumab was given subcutaneously (SC) for 4 cycles (Q3W) concurrently with the taxane component of chemotherapy. After completing their neoadjuvant therapy, participants underwent surgery. Thereafter, participants received an additional 14 cycles of the FDC of pertuzumab and trastuzumab SC for a total of 18 cycles.

Analysis denominator · Participants