BOSTON — Foundation Medicine said the U.S. Food and Drug Administration has approved its FoundationOne CDx tissue test as a companion diagnostic for Itovebi, a Genentech therapy used in certain patients with advanced or metastatic breast cancer.
The approval allows FoundationOne CDx to be used to identify patients with PIK3CA-mutated, hormone receptor-positive, HER2-negative, locally advanced or metastatic breast cancer who may be eligible for Itovebi, also known as inavolisib, in combination with palbociclib and fulvestrant.
Foundation Medicine said the decision follows the FDA’s October 2024 approval of FoundationOne Liquid CDx, the company’s blood-based comprehensive genomic profiling test, for the same therapy combination and indication. The latest approval gives clinicians both tissue- and blood-based testing options to help identify patients who may benefit from the targeted regimen.
Itovebi was developed by Genentech, a member of the Roche Group. The therapy is approved for adult patients with endocrine-resistant, PIK3CA-mutated, hormone receptor-positive, HER2-negative, locally advanced or metastatic breast cancer, as detected by an FDA-approved test, following recurrence on or after completion of adjuvant endocrine therapy.
Foundation Medicine said about 70% of breast cancer cases are hormone receptor-positive and HER2-negative, and PIK3CA mutations are found in about 40% of patients in that group. The company said an analysis from the INAV0120 trial showed high concordance between FoundationOne CDx and FoundationOne Liquid CDx in identifying PIK3CA mutation status.
“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,” said Todd Druley, M.D., Ph.D., chief medical officer at Foundation Medicine. “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 said it is the only company with an FDA-approved portfolio of tissue- and blood-based comprehensive genomic profiling tests. With the latest approval, the company said it has eight FDA-approved companion diagnostic indications for breast cancer and more than 100 approved companion diagnostic indications overall.
“When someone is diagnosed with metastatic breast cancer or experiences a recurrence of their disease, making decisions about treatment can feel extremely overwhelming,” said Jean A. Sachs, MSS, MLSP, chief executive officer at Living Beyond Breast Cancer. “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.”
