TRIO038: A randomized, multicenter, open-label, two-arm, phase II neoadjuvant study evaluating the activity, efficacy, safety and pharmacokinetics of GDC-9545 in combination with palbociclib compared with anastrozole with palbociclib for postmenopausal women with operable estrogen receptor positive (ER+) and HER-2 negative (HER-2-) untreated breast cancer.