A phase III test combining Novartis AG's phosphoinositide 3-kinase (PI3K) inhibitor, BYL-719 (alpelisib), with fulvestrant to treat a genetically-defined subset of advanced breast cancer patients found that it improved progression-free survival in those individuals, as compared to treatment with fulvestrant alone. The top-line success set the stage for the company to move closer to filing global regulatory applications for the drug, which Novartis oncology chief Samit Hirawat called the first of its kind "to show potential increased benefit and acceptable tolerability for patients."