Neoadjuvant Inetetamab Combined With Pertuzumab and Paclitaxel/Carboplatin for Breast Cancer

Inetetamab (Cipterbin) is a newly marketed anti-HER2 monoclonal antibody with amino acid modified Fc region and enhanced antibody-dependent cellular cytotoxicity (ADCC) effect. There was no robust evidence evaluating the combination of inetetamab with pertuzumab and neoadjuvant chemotherapy (paclitaxel + carboplatin) in the neoadjuvant setting. This study aimed to evaluate the efficacy and safety of inetetamab + pertuzumab+paclitaxel + carboplatin (TCbIP) as a neoadjuvant chemotherapy regimen in the treatment of patients with locally advanced HER2-positive breast cancer. The phase II trial included female patients with histologically confirmed stage IIA to IIIC and HER2-positive primary invasive breast cancer. Eligible patients received inetetamab with pertuzumab and paclitaxel/carboplatin (TCbIP) regimen every three weeks for a maximum of 6 cycles, followed by surgery. The primary endpoint was pathologic complete response (pCR; ypT0 ypN0) rate. Key secondary endpoints included near pCR (npCR) (residual breast disease \<1cm), objective response rate (ORR) and safety. Efficacy was analyzed in the intention-to-treat (ITT) and per-protocol (PP) populations. The ITT population included patients who received at least 2 cycles of the study drug but excluded those who were lost to follow-up without surgery and those who received other targeted therapy. The PP population was a subgroup of patients who met all the trial criteria, were compliant with the protocol, and did not violate any major protocols. Safety was analyzed in the safety population, which included all patients who received at least one dose of the study drug and had available safety data. Fisher's exact test was used for the comparisons between patients with pCR and those with non-pCR.