Eli Lilly’s oral selective estrogen receptor degrader (SERD), imlunestrant (Inluriyo), has been approved by the FDA for adults with estrogen receptor-positive, HER2-negative ESR1-mutated advanced or metastatic breast cancer. The second-line treatment demonstrated superior disease progression and survival outcomes in the phase III Ember-3 trial compared to standard endocrine therapy. This approval adds a novel oral therapeutic to the arsenal against difficult-to-treat breast cancers with endocrine resistance.