De-escalation of Neoadjuvant Treatment (Paclitaxel + HP) in Early HER2+ Breast Cancer

This phase II study evaluates the efficacy and safety of a de-escalated neoadjuvant chemotherapy regimen in patients with early-stage HER2-positive breast cancer. The experimental regimen consists of 12 weekly cycles of paclitaxel combined with trastuzumab and pertuzumab (THP), without anthracyclines. The study aims to determine if this less toxic regimen can achieve high rates of pathological complete response (pCR) comparable to standard anthracycline-containing regimens. The results are compared with a historical control group of patients who received the standard TCHP regimen (docetaxel, carboplatin, trastuzumab, pertuzumab). A total of 186 participants are included in the analysis: 93 patients prospectively treated with the de-escalated THP regimen and 93 patients in the retrospective historical control group (TCHP). The primary endpoint is the pCR rate at the time of surgery. Secondary endpoints include toxicity, rate of breast-conserving surgery, and 3-year event-free survival.