Fig 4.

Biomarker analyses in archived tissue. (A) Concordance of heregulin (HRG) and human epidermal growth factor receptor 2 (HER2) status between archived tissue and pretreatment biopsies in patient-matched samples. HRG high, HRG score ≥ 1; HRG low, HRG score < 1; HER2 high, HER2 ≥ 126,000 receptors per cell; HER2 low, HER2 < 126,000 receptors per cell. (B) Relationship between local progression-free survival hazard ratio (HR; seribantumab [S] + paclitaxel [P] v P) and HRG reverse-transcriptase quantitative polymerase chain reaction (RT-PCR) values in archived tissue. HRs were estimated at different values of HRG by including all patients with HRG levels within one standard deviation of the measurement error. The number of patients used for each HR estimation is indicated by the size of the dot. LLOQ, lower limit of quantification. CT, cycle threshold.