Five-Year Analysis Of The Phase Ii Neosphere Trial Evaluating Four Cycles Of Neoadjuvant Docetaxel (D) And/Or Trastuzumab (T) And/Or Pertuzumab (P).

505 Background: InNeoSphere, four cycles of T+D, P+T+D, P+T, or P+D, followed by surgery and adjuvant chemotherapy plus conventional T, were evaluated in 417 women with locally advanced, inflammatory, or early HER2-positive breast cancer. The addition of P to T+D led to a statistically significant and clinically meaningful 16.8% increase (95% confidence interval [CI], 3.5–30.1; P = .0141) in pathologic complete response rate (pCR) in the breast (bpCR, ypT0/is; primary endpoint), and a 17.8% increase in total pCR in the breast and axilla (tpCR, ypT0/is, ypN0). Methods: A pre-planned descriptive intent-to-treat analysis was conducted 5 years after randomization of the last patient, to evaluate disease-free survival (DFS; time from surgery until progression or death) and progression-free survival (PFS; time from randomization until progression or death, equivalent to the commonly used definition of event-free survival). Results: Three-year survival rates, hazard ratios (HRs), and 95% CIs for the main analysi...