Genomically Targeted Therapy Delays Advanced Breast Cancer Progression

MUNICH—A combination of the phosphoinositide 3-kinase (PI3K) inhibitor alpelisib plus fulvestrant significantly extended progression free survival (PFS) compared to placebo plus fulvestrant in patients with hormone receptor positive (HR+) human epidermal growth factor receptor 2-negative (HER2−) advanced breast cancer in the randomized phase three SOLAR-1 trial reported at the 2018 annual congress of the European Society for Medical Oncology, ESMO.

“This study opens the door for precision medicine in metastatic breast cancer,” said lead investigator Fabrice André MD PhD, Associate Professor in the Department of Medical Oncology at Institut Gustave Roussy in Villejuif, France. This had been the first study to show statistically significant clinically meaningful PFS improvement with an alpha isoform-specific PI3K inhibitor in patients with HR+ HER2- advanced breast cancer and mutated oncogene PIK3CA, he said, and the drug had a “manageable toxicity profile”.

“[This] alpha selective PI3 kinas inhibitor improves progression free survival in a clinically meaningful way in patients who present [with] mutational PI3 kinase,” André tells the Audio Journal of Oncology. He noted that SOLAR-1 had been the first study to show a benefit from a targeted therapy driven by genomics.