In a double-blind, placebo-controlled, phase 2 study (ENCORE 301, N = 130) of ENT in combination with exemestane (EXE) in patients with HR+/HER2− advanced or metastatic BC, the ENT + EXE group showed improved PFS (median 4.3 vs. 2.3 months; hazard ratio [HR] 0.73; 95% CI 0.50–1.07; one-sided P = 0.055) and OS (median 28.13 vs. 19.84 months; HR 0.59; 95% CI 0.36–0.97; one-sided P = 0.018) compared with placebo + EXE [20]. Here, ERBB2 is linked to breast cancer.