PIK3CA and breast cancer: In the phase III SOLAR-1 study (ClinicalTrials.gov Identifier: NCT02437318), post-menopausal women with HR+/HER-2 negative advanced BC were given either alpelisib/placebo (a PI3Kα specific inhibitor) in combination with fulvestrant and a significant extension in the PFS was reported in patients with PIK3CA mutations in the alpelisib arm of the study (276).