The diagnostic test identifies specific genetic mutations to help select patients for a targeted therapy combination.
The Food and Drug Administration (FDA) approved FoundationOne CDx as a companion diagnostic for Itovebi (inavolisib) in combination with palbociclib (Ibrance) and fulvestrant.
Itovebi, developed by Genentech, is approved for adult patients with endocrine-resistant, PIK3CA-mutated, hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative, locally advanced or metastatic breast cancer. The therapy is indicated for use following recurrence on or after completing adjuvant endocrine therapy, according to a press release from Foundation Medicine.
The FDA approval follows the October 2024 approval of FoundationOne Liquid CDx, a blood-based genomic profiling test, for the same therapy combination and indication.
Approximately 70% of breast cancer cases are HR-positive and HER2-negative, and PIK3CA is mutated in about 40% of these patients, according to the release. An analysis of the INAV0120 trial showed high concordance in identifying PIK3CA mutation status between the tissue-based FoundationOne CDx and the blood-based FoundationOne Liquid CDx tests.
“The prevalence of PIK3CA mutations found in HR-positive, HER2-negative breast cancer makes it extremely important to have high-quality, FDA-approved tests to match patients to the most effective therapy options in a timely manner,” says Todd Druley, chief medical officer at Foundation Medicine, in a release. “While actionable genomic alterations like PIK3CA may be identified by blood-based biopsy, some patients’ tumors may not be shedding adequate levels of tumor DNA into the blood for these alterations to be detected. In these cases, confirmatory tissue testing may help match more breast cancer patients to this therapy.”
Foundation Medicine currently has eight companion diagnostic indications for breast cancer and more than 100 companion diagnostic indications, according to the company.
“When someone is diagnosed with metastatic breast cancer or experiences a recurrence of their disease, making decisions about treatment can feel extremely overwhelming,” says Jean A. Sachs, CEO at Living Beyond Breast Cancer, in a release. “Having two high-quality FDA-approved biomarker tests to detect PIK3CA mutations using different sample types opens more doors to help match patients to this targeted treatment regimen in the first-line setting.”
ID 23050558 © Brad Calkins | Dreamstime.com
