As reported in the Journal of Clinical Oncology by Yamamoto et al, the final overall survival analysis of the Japanese phase III PRECIOUS study showed a significant benefit with the addition of pertuzumab retreatment to trastuzumab plus physician’s choice of chemotherapy (PTC) in patients with HER2-positive locally advanced/metastatic breast cancer.
The primary analysis of the trial showed a significant benefit in investigator-assessed progression free survival with PTC vs trastuzumab plus physician’s choice of chemotherapy (TC).
Study Details
In the open-label multicenter trial, 219 patients who had received pertuzumab-containing regimens as first- or second-line treatment for locally advanced/metastatic disease were randomly assigned to PTC (n = 110) or TC (n = 109). Physician’s choice of chemotherapy was most commonly eribulin (58% vs 43%) and vinorelbine (24% vs 37%).
Key Findings
At a median follow-up of 25.8 months (interquartile range = 13.2–41.2 months), the final overall survival analysis showed a median overall survival of 36.2 months (95% confidence interval [CI] = 24.4–43.0 months) in the PTC group vs 26.5 months (95% CI = 20.0–35.0 months) in the TC group (hazard ratio [HR] = 0.73, 95% CI = 0.55–0.97).
Updated median investigator-assessed progression-free survival was 5.5 months (95% CI = 4.1–6.5 months) in the PTC group vs 4.2 months (95% CI = 3.2–4.8 months) in the TC group (HR = 0.81, one-sided 95% CI upper limit = 1.02). Median progression-free survival on independent review was 4.4 months (95% CI = 3.2–5.8 months) in the PTC group vs 4.4 months (95% CI = 3.7–5.6 months) in the TC group (HR = 1.03, one-sided 95% CI upper limit = 1.36).
The investigators concluded: “These findings suggest that dual HER2 blockade with pertuzumab plus trastuzumab could contribute to improving [overall survival] in patients who have previously been treated with pertuzumab-containing regimens for HER2-positive [locally advanced/metastatic breast cancer].”
Yutaka Yamamoto, MD, PhD, of Kumamoto University Hospital, Japan, is the corresponding author for the Journal of Clinical Oncology article.
Disclosure: The study was supported by the Japan Breast Cancer Research Group and by Chugai Pharmaceutical Co, Ltd. For full disclosures of the study authors, visit ascopubs.org.
