The US Food and Drug Administration approved Eli Lilly's Inluriyo-Verzenio combination for adults with metastatic breast cancer that is estrogen receptor-positive, HER2-negative and carries an ESR1 mutation, after the disease worsened following at least one hormone treatment. In a late-stage study of 159 patients, the combination delayed cancer worsening for a median of 11.1 months, compared with 5.5 months for Inluriyo alone. Lilly said about half of patients with ER-positive, HER2-negative metastatic breast cancer develop an ESR1 mutation during or after treatment with widely used hormone-blocking therapies. Inluriyo, which received FDA approval in September last year for ESR1-mutated metastatic breast cancer, blocks and breaks down estrogen receptors, while twice-daily Verzenio slows cancer-cell division. The combination can cause severe diarrhea, low white blood cell counts, lung inflammation, liver problems and blood clots. Inluriyo's label also warns of embryo-fetal toxicity, meaning potential harm to a developing embryo or fetus during pregnancy. The combination is available immediately in the United States.