FDA Approves FoundationOne CDx Tests as Companion Diagnostics for TALZENNA and XTANDI in HRR Gene–Mutated Metastatic Castration-Resistant Prostate Cancer
Foundation Medicine, a global precision medicine company dedicated to advancing personalized cancer care, has announced a significant regulatory milestone with the approval of two of its comprehensive genomic profiling tests by the U.S. Food and Drug Administration (FDA). The agency has approved both FoundationOne® CDx and FoundationOne® Liquid CDx as companion diagnostics for Pfizer’s TALZENNA® (talazoparib) when used in combination with XTANDI® (enzalutamide) for the treatment of patients with homologous recombination repair (HRR) gene-mutated metastatic castration-resistant prostate cancer (mCRPC).
The approvals represent an important advancement in precision oncology, helping physicians identify patients who may benefit from the TALZENNA and XTANDI combination therapy. By enabling both tissue-based and blood-based genomic testing, the newly approved companion diagnostics provide clinicians with additional tools to determine whether a patient’s cancer contains specific HRR gene mutations that may make them eligible for targeted treatment.
The milestone further reinforces the growing role of comprehensive genomic profiling in prostate cancer management and highlights the increasing importance of biomarker-driven treatment strategies in advanced cancer care.
Expanding Precision Medicine Options for Prostate Cancer Patients
Prostate cancer remains one of the most frequently diagnosed cancers among men worldwide and continues to be a major public health concern. In the United States alone, approximately one in eight men will receive a prostate cancer diagnosis during their lifetime. While many cases can be successfully managed when detected early, advanced forms of the disease remain challenging to treat.
One of the most aggressive stages of the disease is metastatic castration-resistant prostate cancer, commonly known as mCRPC. This condition develops when prostate cancer continues to grow and spread despite treatments designed to suppress testosterone, a hormone that typically fuels prostate cancer growth.
Patients diagnosed with mCRPC often face limited treatment options and a less favorable prognosis compared with individuals whose disease remains confined to the prostate. Although recent advances have introduced new therapeutic approaches, there remains a critical need for personalized treatment strategies capable of improving outcomes for these patients.
Scientific research has shown that approximately 20% to 30% of patients with metastatic castration-resistant prostate cancer carry mutations in homologous recombination repair genes. These genes play an essential role in repairing damaged DNA within cells. When these repair mechanisms become impaired, cancer cells may become more vulnerable to therapies that exploit defects in DNA repair pathways, including PARP inhibitors such as TALZENNA.
Supporting the First PARP Inhibitor Combination of Its Kind
The FDA approvals are particularly significant because TALZENNA is currently the first and only PARP inhibitor approved for use in combination with an established standard-of-care therapy, XTANDI, for adult patients with both BRCA-mutated and non-BRCA HRR gene-mutated metastatic castration-resistant prostate cancer.
Historically, many PARP inhibitor therapies have focused primarily on patients with BRCA gene alterations. However, the approval of TALZENNA in combination with XTANDI expands treatment opportunities to a broader group of patients carrying a wider range of HRR gene mutations.
This development underscores the importance of comprehensive genomic testing. Identifying the full spectrum of clinically relevant genomic alterations can help physicians determine which patients are most likely to benefit from targeted therapies and combination treatment approaches.
The approval of FoundationOne CDx and FoundationOne Liquid CDx provides healthcare providers with validated diagnostic tools capable of detecting these critical genomic alterations, helping ensure that appropriate patients can be identified for treatment.
Importance of Tissue and Blood-Based Testing
One of the key advantages of Foundation Medicine’s companion diagnostic portfolio is its ability to offer both tissue-based and liquid biopsy testing options.
FoundationOne CDx analyzes tumor tissue samples to identify a broad range of genomic alterations across hundreds of cancer-related genes. This approach has become a cornerstone of precision oncology by providing detailed molecular information about a patient’s tumor.
Meanwhile, FoundationOne Liquid CDx uses a blood sample to detect circulating tumor DNA shed by cancer cells into the bloodstream. Liquid biopsy testing offers an alternative option when tissue samples are unavailable, insufficient, or difficult to obtain.
Together, these complementary testing methods help expand access to genomic profiling and increase the likelihood that patients can receive timely molecular testing regardless of clinical circumstances.
The availability of both tissue and blood-based companion diagnostics also supports greater flexibility for physicians and healthcare systems seeking to integrate precision medicine into routine cancer care.
Foundation Medicine Strengthens Its Leadership in Companion Diagnostics
According to Foundation Medicine, the latest FDA approvals further expand its position as a leader in companion diagnostics and comprehensive genomic profiling.
The company currently maintains the only FDA-approved portfolio that includes both tissue-based and blood-based comprehensive genomic profiling tests. This integrated testing platform allows healthcare providers to select the most appropriate diagnostic approach based on each patient’s unique clinical situation.
Todd Druley, M.D., Ph.D., Chief Medical Officer at Foundation Medicine, emphasized the importance of individualized treatment planning for patients with advanced prostate cancer.
He noted that every patient deserves personalized information that can help guide treatment decisions and that generalized approaches are often insufficient in an era where targeted therapies are becoming increasingly available. As the treatment landscape for metastatic castration-resistant prostate cancer continues to evolve, access to reliable companion diagnostic testing becomes essential for matching patients with the therapies most likely to benefit them.
Dr. Druley also highlighted that the dual approvals reinforce the company’s commitment to advancing precision medicine and demonstrate the critical role comprehensive genomic profiling plays in connecting patients with targeted treatment opportunities.
Growing Portfolio of FDA-Approved Companion Diagnostic Indications
The newly approved indications add to Foundation Medicine’s already extensive portfolio of FDA-authorized companion diagnostics.
With the addition of the TALZENNA and XTANDI indication, the company now has nine FDA-approved companion diagnostic indications specifically related to prostate cancer. Across all cancer types, Foundation Medicine has accumulated more than 100 approved companion diagnostic indications.
This achievement reflects years of collaboration among pharmaceutical companies, regulators, researchers, and healthcare providers aimed at integrating genomic information into clinical decision-making.
The growing number of approvals also illustrates how precision medicine continues to reshape cancer treatment. Rather than relying solely on the location where a cancer originates, modern oncology increasingly focuses on the specific molecular characteristics driving tumor growth.
By identifying actionable genomic alterations, clinicians can select therapies that target the underlying biology of a patient’s disease, potentially improving treatment effectiveness and patient outcomes.
Addressing Gaps in Access to Biomarker Testing
While advances in precision oncology have created new opportunities for patients, access to biomarker testing remains an ongoing challenge in many healthcare settings.
Advocacy organizations have repeatedly emphasized that many patients still do not receive the molecular testing needed to guide treatment decisions. Factors such as geographic location, healthcare infrastructure, insurance coverage, and physician awareness can all influence access to genomic profiling services.
Courtney Bugler, President and Chief Executive Officer of ZERO Prostate Cancer, stressed the importance of ensuring equitable access to biomarker testing for all patients.
She noted that the issue is often not the availability of testing technology itself but rather inconsistencies in access across different healthcare environments. Biomarker testing provides patients and their families with valuable information about their diagnosis and treatment options, helping them make more informed decisions regarding their care.
Bugler emphasized that every patient deserves access to personalized treatment insights regardless of where they live, who provides their medical care, or the specifics of their diagnosis.
Advancing the Future of Precision Oncology
The FDA approvals for FoundationOne CDx and FoundationOne Liquid CDx mark another important step in the ongoing evolution of precision medicine for prostate cancer. As researchers continue to uncover the molecular drivers of cancer progression, genomic profiling is becoming an increasingly essential component of oncology care.
By enabling the identification of HRR gene mutations in patients with metastatic castration-resistant prostate cancer, the newly approved companion diagnostics support broader access to targeted therapies such as TALZENNA in combination with XTANDI. The approvals also reinforce the value of comprehensive genomic profiling as a critical tool for personalized treatment selection.
For patients facing advanced prostate cancer, the ability to access accurate molecular testing can play a pivotal role in determining the most appropriate therapeutic strategy. As the precision oncology landscape continues to expand, Foundation Medicine’s latest regulatory achievement highlights the growing importance of integrating genomic insights into routine cancer care and ensuring that more patients can benefit from innovative, biomarker-guided treatments.
About Foundation Medicine
Foundation Medicine is a global, patient-focused precision medicine company delivering high-quality, transformative diagnostic solutions in cancer and other diseases. We provide tests and solutions to transform care throughout a patient’s experience, from defining a diagnosis to determining the appropriate treatment to ongoing monitoring.
We help accelerate the development of new personalized therapies by leveraging our vast knowledge of precision medicine, real world data and AI-powered tools, expanding the information our diagnostic solutions provide to enable improved outcomes for patients. Every day, we are inspired to think differently to transform the lives of people living with cancer and other diseases. For more information, visit us at www.FoundationMedicine.com and follow us on LinkedIn, X, YouTube, Facebook, Instagram and BlueSky.
About FoundationOne®CDx
FoundationOne®CDx is for prescription use only and is an FDA-approved qualitative next-generation sequencing based in vitro diagnostic test for advanced cancer patients with solid tumors. The test analyzes 324 genes as well as genomic signatures including microsatellite instability (MSI) and tumor mutational burden (TMB) and is a companion diagnostic to identify patients who may benefit from treatment with specific therapies in accordance with the approved therapeutic product labeling.
Additional genomic findings may be reported and are not prescriptive or conclusive for labeled use of any specific therapeutic product. Use of the test does not guarantee a patient will be matched to a treatment. A negative result does not rule out the presence of an alteration. Some patients may require a biopsy which may pose a risk. For the complete label, including companion diagnostic indications and important risk information, please visit www.F1CDxLabel.com.
About FoundationOne®Liquid CDx
FoundationOne®Liquid CDx is for prescription use only and is an FDA-approved qualitative next-generation sequencing based in vitro diagnostic test for advanced cancer patients with solid tumors. The test analyzes 324 genes utilizing circulating cell-free DNA and is FDA-approved to report short variants in 311 genes, rearrangements in 8 genes and copy number alterations in 3 genes, and as a companion diagnostic to identify patients who may benefit from treatment with specific therapies in accordance with the approved therapeutic product labeling. Additional genomic findings may be reported and are not prescriptive or conclusive for labeled use of any specific therapeutic product.
Use of the test does not guarantee a patient will be matched to a treatment. A negative result does not rule out the presence of an alteration. When considering eligibility for ROZLYTREK® based on the detection of NTRK1/2/3 and ROS1 fusions, or for TEPMETKO® based on the detection of MET SNVs and indels that lead to MET exon 14 skipping, testing using plasma specimens is only appropriate for patients for whom tumor tissue is not available for testing. Patients who are negative for companion diagnostic mutations should be reflexed to tumor tissue testing and mutation status confirmed using an FDA-approved tumor tissue test, if feasible.
