Pertuzumab Retreatment Improves Survival for Patients With HER2-Positive Advanced Breast Cancer

Final Overall Survival Results From the Phase 3 PRECIOUS Study 

According to updated results from the phase 3 PRECIOUS study, the addition of pertuzumab retreatment to trastuzumab and physician’s choice chemotherapy improved survival among patients with human epidermal growth factor receptor 2 (HER2)-positive, locally advanced or metastatic breast cancer. 

In this multicenter, open-label trial, 211 patients with HER2-positive, locally advanced or metastatic breast cancer were randomized on a 1-to-1 basis to receive trastuzumab plus physician’s choice chemotherapy either with (n = 108) or without pertuzumab retreatment (n = 109). The primary end point was investigator-assessed PFS. Key secondary end points included overall survival (OS), independent-reviewer-assessed PFS, and safety. Primary analysis results demonstrated that “pertuzumab retreatment combined with trastuzumab plus chemotherapy of physician's choice significantly improved investigator-assessed progression-free survival (PFS) compared with trastuzumab plus physician's choice chemotherapy,” stated Yutaka Yamamoto, MD, PhD, Kumamoto University Hospital, Honjo, Chuo-ku, Kumamoto, Japan, and coauthors. Here, the final overall survival results are reported. 

At a median follow-up of 25.8 months, investigator-assessed PFS events occurred in 87% of patients in the pertuzumab arm and 88.1% of patients in the control arm. Investigator-assessed median PFS was 5.5 months and 4.2 months, respectively. Median OS was 36.2 months in the pertuzumab arm and 26.5 months in the control arm. Independent reviewer-assessed PFS events occurred in 67.3% of patients in the pertuzumab arm and 68.6% of patients in the control arm. No new safety signals were identified except for a higher incidence of diarrhea in the pertuzumab arm. There were 61 deaths in the pertuzumab arm and 77 deaths in the control arm. 

As Dr Yamamoto et al concluded, “retreatment with the same dual HER2 blockade of pertuzumab plus trastuzumab could contribute to improving survival in patients who were previously treated with dual HER2 blockade using pertuzumab and trastuzumab as first- or second-line therapy.” 

Source: 

Yamamoto Y, Iwata H, Saji S, et al. Pertuzumab retreatment for human epidermal growth factor receptor 2–positive locally advanced/metastatic breast cancer (PRECIOUS Study): Final overall survival analysis. J Clin Oncol. Published online: January 24, 2025. doi: 10.1200/JCO-24-01673