Key clinical point: Patients with trastuzumab-refractory human epidermal growth factor receptor 2 positive (HER2+) metastatic breast cancer achieved satisfactory clinical efficacy after switching to lapatinib as the HER2-blockade therapy.
Major finding: After a median follow-up of 33.1 months, patients achieved a median progression free survival (PFS) of 8.5 months, with brain metastases (hazard ratio [HR] 1.582; P = .041) and ≥2 metastatic sites (HR 1.679; P = .007) being independent prognostic markers for PFS. Diarrhea (3.8%) and hand-foot syndrome (9.4%) were the most common grade ≥3 adverse events.
Study details: Findings are from the phase 2 SYSUCC-005 study including 159 women with HER2-positive refractory metastatic breast cancer who rapidly progressed during prior adjuvant/first-line trastuzumab therapy and switched to lapatinib with either capecitabine or vinorelbine.
Disclosures: This study was funded by the Joint Fund of the National Natural Science Foundation of China and Natural Science Foundation of Guangdong Province, among other sources. The authors declared no conflicts of interest.
Source: Duan F et al. The efficacy of human epidermal growth factor receptor 2 (HER2) blockade switching mode in refractory patients with HER2-positive metastatic breast cancer: A phase II, multicenter, single-arm study (SYSUCC-005). BMC Cancer. 2022;22:271 (Mar 15). Doi: 10.1186/s12885-022-09399-2