FDA Approves FoundationOne Liquid CDx as Companion Diagnostic for Itovebi (Inavolisib) in HR‑Positive, HER2‑Negative Breast Cancer with PIK3CA Mutation

On October 10, 2024, the U.S. Food and Drug Administration (FDA) approved the FoundationOne Liquid CDx assay as a companion diagnostic device to identify breast cancer patients for treatment with Itovebi (inavolisib) in combination with palbociclib and fulvestrant.

This approval is for adults 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 completing adjuvant endocrine therapy.

FoundationOne Liquid CDx is a liquid‑biopsy‑based comprehensive genomic profiling test that detects PIK3CA mutations in circulating tumor DNA from a routine blood draw, thereby broadening access to genomic testing for this patient population.

The companion diagnostic designation for FoundationOne Liquid CDx supports the use of Itovebi, a selective PI3Kα inhibitor developed by Genentech (Roche), as part of a best‑in‑class first‑line regimen for eligible patients with this biomarker‑defined breast cancer subset.

Separately, the tissue‑based test FoundationOne CDx is also approved as a companion diagnostic for other PIK3CA‑targeted therapies in breast cancer, reinforcing its role as a broad‑spectrum genomic profiling platform for solid tumors.