Alpelisib received Food and Drug Administration and European Medicines Agency approval based on SOLAR-1, a phase III, randomized, double-blinded, placebo-controlled trial that evaluates the efficacy and toxicity profile of alpelisib or placebo in combination with fulvestrant in 572 postmenopausal patients with HR+/HER2- advanced breast cancer whose disease had progressed or relapsed during or after treatment with an aromatase inhibitor (30). This evidence concerns the gene CYP19A1 and breast cancer.