According to results from the phase 3 neoCARHP trial, de-escalated neoadjuvant taxane therapy plus trastuzumab and pertuzumab without the addition of carboplatin demonstrated promise among patients with human epidermal growth factor receptor 2 (HER2)-positive early breast cancer. 

These data were first presented by Kun Wang, MD, Guangdong Provincial People’s Hospital, Guangzhou, China, at the 2025 American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago, Illinois. 

In this open-label, non-inferiority trial, 766 patients with stage 2 to 3 invasive, HER2-positive breast cancer were randomized on a 1-to-1 basis to receive an investigator-selected taxane (docetaxel, paclitaxel, or nab-paclitaxel) plus trastuzumab (8 mg/kg loading dose followed by 6 mg/kg every 3 weeks) and pertuzumab (840 mg loading dose followed by 420 mg every 3 weeks) with (n = 382) or without (n = 384) carboplatin (AUC 6 mg/mL per minute). Patients were stratified based on nodal and hormone receptor status. The primary end point was pathological complete response (pCR) rate.  A key secondary end point was safety.

At analysis, pCR rate was 64.1% in the non-carboplatin arm and 65.9% in the carboplatin arm (absolute difference -1.8%; odds ratio 0.93; 95% confidence interval [CI], 0.69 to 1.25; P = .0089). Among patients with ER- or PR-negative disease, the pCR rates were 78.2% and 77.8%, respectively. Among patients with ER- and/or PR-positive disease, the pCR rates were 55.8% and 58.8%, respectively. Grade 3/4 adverse events occurred in 20.7% of patients in the non-carboplatin arm and 34.6% of patients in the carboplatin arm, the most common including neutropenia, leukopenia, and diarrhea. Serious adverse events occurred in 1.3% and 4.7% of patients, respectively. No treatment-related deaths occurred.

Dr Wang concluded, “Taxane, trastuzumab, and pertuzumab (THP) achieved non-inferior pCR, improved tolerability, and retained the patient-friendly 3-weekly dosing schedule compared with the standard taxane, carboplatin, trastuzumab, and pertuzumab (TCbHP).” He continued, “Omitting carboplatin could be an efficacious de-escalated neoadjuvant strategy in the presence of dual HER2 blockade for patients with HER2-positive early breast cancer.” 

Source: 

Gao HF, Li W, Wu Z, et al. De-escalated neoadjuvant taxane plus trastuzumab and pertuzumab with or without carboplatin in HER2-positive early breast cancer (neoCARHP): A multicentre, open-label, randomised, phase 3 trial. Presented at 2025 ASCO Annual Meeting. May 30-June 3, 2025; Chicago, IL. Abstract LBA500