Eli Lilly's experimental breast cancer drug, imlunestrant, met its main goal in a Phase 3 study, showing improved progression-free survival in HER2-negative, ER-positive patients. Combined with Verezenio, it offered longer survival and progression-free benefits. Imlunestrant, a next-gen SERD, aims to overcome resistance, particularly from ESR1 mutations. The trial enrolled 874 patients, with imlunestrant plus Verezenio reducing progression or death risk by 43% compared to imlunestrant alone. Side effects were higher with the combination treatment.