ERBB2 and breast cancer: In the SOLAR-1 trial, the combination of alpelisib and fulvestrant increased the median overall survival of patients with PIK3CA-mutated HR+/HER2− advanced breast cancer compared to those treated with fulvestrant and a placebo (39.3 vs. 31.4 months; hazard ratio, 86; 95% confidence interval, 0.64–1.15; p = 0.15), although the analysis did not cross the prespecified boundary for statistical significance [54].