The FDA cleared Foundation Medicine’s FoundationOne CDx assays as companion diagnostics for identifying eligible patients for Pfizer’s Talzenna (talazoparib) plus Xtandi (enzalutamide) in metastatic castration-resistant prostate cancer (mCRPC) with homologous recombination repair (HRR) gene mutations. The tissue-based NGS test covers 324 genes and includes genomic signatures used to determine microsatellite instability and tumor mutational burden status, expanding the assay’s operational footprint in precision prostate oncology. With the diagnostic clearance tied to treatment selection, the approval can influence testing workflows for oncology centers managing HRR-driven treatment decisions and may affect payer and lab utilization patterns. For biotech and diagnostics developers, the move reinforces the continued coupling of specific therapy combinations to validated NGS panels and interpretive frameworks.