On December 4, the U.S. Food and Drug Administration (FDA) approved FoundationOne CDx to be used as a companion diagnostic for alpelisib in combination with fulvestrant for the treatment of postmenopausal women as well as male patients with hormone receptor–positive, HER2-negative, PIK3CA-mutated, advanced or metastatic breast cancer following disease progression on or after an endocrine-based regimen. FoundationOne CDx is the first FDA-approved broad comprehensive genomic-profiling test for all solid tumors that incorporates multiple companion diagnostics.
In May 2019, the FDA approved alpelisib in combination with fulvestrant in this treatment setting. PIK3CA is the most commonly mutated gene in hormone receptor–positive, HER2-negative breast cancer; approximately 40% of patients with this disease type have this mutation. ■