Oncology · 2 h ago
Trastuzumab Rezetecan Improves Progression-Free Survival in ERBB2-Low Breast Cancer
In the phase 3 HORIZON-Breast06 trial, 551 women with ERBB2-low advanced breast cancer in China were randomized to trastuzumab rezetecan or physician’s-choice chemotherapy. Median progression-free survival was about 16 months with the antibody-drug conjugate versus about 7 months with chemotherapy, with more grade 3 or higher treatment-related adverse events.
- Phase 3 trial randomized 551 patients at 73 Chinese hospitals.
- Median progression-free survival: 16.4 vs 6.8 months overall.
- Grade 3 or higher treatment-related events: 84.1% vs 67.9%.
- Benefit was reported across hormone receptor subgroups.
HORIZON-Breast06 was an open-label, randomized phase 3 trial conducted at 73 hospitals in China. It enrolled 551 women aged 18 to 75 years with centrally confirmed ERBB2-low unresectable locally recurrent or metastatic breast cancer, who had received no more than one prior chemotherapy regimen for metastatic disease. Participants received trastuzumab rezetecan or physician’s-choice chemotherapy. The primary endpoint was progression-free survival assessed by blinded independent central review.
At the March 20, 2026, data cutoff, median progression-free survival in the overall population was 16.4 months with trastuzumab rezetecan and 6.8 months with chemotherapy (hazard ratio, 0.27; 95% CI, 0.21-0.34; P<.001). Results were similar in chemotherapy-naive patients and across hormone receptor subgroups. Grade 3 or higher treatment-related adverse events occurred in 84.1% versus 67.9%, respectively; decreased neutrophil count was the most common event in both groups.
The findings show a substantial progression-free survival benefit in this trial population, alongside greater severe toxicity. The study was conducted exclusively in China, and the supplied report does not establish regulatory status or an overall-survival benefit; the results alone do not establish a change in clinical practice.
In practice
For women with ERBB2-low unresectable locally recurrent or metastatic breast cancer matching the trial criteria, trastuzumab rezetecan improved progression-free survival versus physician’s-choice chemotherapy in this randomized phase 3 study. Grade 3 or higher treatment-related adverse events were more frequent with trastuzumab rezetecan (84.1% vs 67.9%). The trial was conducted at hospitals in China, and the supplied report does not establish regulatory status or an overall-survival benefit; these results do not by themselves justify changing practice.
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JAMA: Trastuzumab Rezetecan in ERBB2-Low Advanced Breast Cancer ↗This is an automated AI-condensed summary that has not yet been reviewed by an editor. Always consult the full item at the original source.