The PFS benefit associated with elacestrant was consistent across clinically relevant subgroups evaluated, including patients with bone metastases, liver and/or lung metastases, <3 or ≥3 metastatic sites, PIK3CA-mutated tumors, TP53-mutated tumors, HER2-low tumor expression, or ESR1 mutation variants D538G or Y537S/N. Here, TP53 is linked to neoplasm.