The FDA approved Foundation Medicine’s FoundationOne CDx assays as companion diagnostics for Pfizer’s Talzenna plus Xtandi regimen in metastatic castration-resistant prostate cancer with homologous recombination repair (HRR) gene mutations. This clearance extends the clinical utility of FoundationOne CDx in informing patient selection for a genomics-driven treatment strategy. The regulatory action reinforces the role of next-generation sequencing in prostate oncology, where biomarker status can determine whether patients are candidates for particular combination therapies. Separate entries in the provided material reference the same FDA approval. For diagnostics companies and companion diagnostic providers, each CDx expansion can influence adoption rates, reimbursement pathways, and the broader standard-of-care diagnostic workflow.