neoCARHP trial supports carboplatin omission in select HER2-positive early breast cancers

The omission of carboplatin from a dual human epidermal growth factor receptor 2 (HER2)-targeted, taxane-based neoadjuvant regimen does not compromise efficacy and may offer a more tolerable path forward for select participants.

The open-label, multicentre, phase 3 neoCARHP study in China (NCT04858529) compared the efficacy and safety of neoadjuvant taxane, trastuzumab, and pertuzumab administered with carboplatin (TCHP) versus without carboplatin (THP) for HER2-positive breast cancer. Dr Kun Wang (Guangdong Provincial People’s Hospital, China) presented the results [1].

The participants (n=774) were 1:1 randomised to TCHP or THP, respectively, and treated every 3 weeks before surgery. The primary endpoint was the percentage of pathological complete response (pCR), which was defined as the absence of any residual invasive cancer in both the breast and axillary lymph nodes.

pCR was achieved in 64.1% of participants receiving THP compared with 65.9% receiving TCHP (absolute difference −1.8%; odds ratio 0.93; 95% CI 0.69–1.25; P=0.0089). These results met the predefined non-inferiority margin, indicating that omitting carboplatin did not result in inferior pathological responses. Importantly, the non-inferiority of THP held across subgroups stratified by hormone receptor status, tumour size, and nodal involvement.

The neoCARHP findings provide much-needed clarity around the role of carboplatin, particularly for patients with lower disease burden. Dr Wang noted that particularly participants with T1–T2/N0–N2 staged tumours may benefit most from the de-escalated THP approach. “This trial answers a longstanding question about the necessity of carboplatin in HER2-positive early breast cancer. Our data suggest that many patients can achieve similar outcomes with less toxicity,” Dr Wang stated.

Discussant Dr Sara Hurvitz (Fred Hutchinson Cancer Center, WA, USA) praised the trial's design and clinical relevance but urged careful participant selection. She noted that only about 25% of trial participants had stage 3 disease, and most had small tumours, limiting generalisability to patients with more advanced disease. “This is welcome news for many clinicians and patients. But we must remember that pCR is a surrogate marker,” Dr Hurvitz highlighted. “We need longer-term data on event-free and overall survival to make confident treatment shifts.” She added that future analyses of patient-reported outcomes will be crucial to understanding the true value of carboplatin omission from a quality-of-life perspective.

1. Gao, HF, 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. Abstract LBA500, ASCO Annual Meeting 2025, 30 May–3 June, Chicago, IL, USA.

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Posted on 30 July 2025