Early Switch to Fulvestrant Plus Palbociclib Improves Outcomes in ESR1-Mutated, Estrogen Receptor-Positive Metastatic Breast Cancer

For patients with estrogen receptor-positive metastatic breast cancer who are treated with palbociclib plus an aromatase inhibitor, the strategy of switching to palbociclib plus fulvestrant upon detection of a resistance mutation more than doubled progression-free survival, according to results from the phase III PADA-1 trial.