SALT LAKE CITY, March 17, 2026
Myriad Genetics, Inc. announced that the U.S. Food and Drug Administration (FDA) has approved its MyChoice® CDx test as a companion diagnostic for Zejula® (niraparib) in patients with advanced ovarian cancer, marking a significant advancement in precision oncology and biomarker-driven treatment selection. The approval reinforces the critical role of homologous recombination deficiency (HRD) testing in identifying patients most likely to benefit from targeted PARP inhibitor therapy, supporting more personalized and effective cancer care.
FDA Approval Enables Precision Treatment Selection
The FDA approval of the MyChoice® CDx test establishes it as the only approved companion diagnostic in the United States for identifying HRD-positive patients eligible for Zejula therapy. The test plays a crucial role in guiding treatment decisions by determining HRD status, which is a key biomarker associated with response to PARP inhibitors.
This milestone highlights the increasing importance of companion diagnostics in oncology, where treatment strategies are increasingly tailored based on molecular and genetic profiling of tumors. By enabling precise patient selection, the MyChoice CDx test helps ensure that targeted therapies are administered to those most likely to benefit, improving both clinical outcomes and healthcare efficiency.
Advanced Genomic Testing Improves Patient Stratification
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The MyChoice® CDx test utilizes next-generation sequencing (NGS) technology to perform a comprehensive assessment of BRCA1/2 gene mutations and genomic instability markers, including loss of heterozygosity (LOH), telomeric allelic imbalance (TAI), and large-scale state transitions (LST). This advanced approach allows for a more accurate identification of HRD-positive tumors, capturing a broader patient population compared to traditional testing methods.
Clinical data from the PRIMA trial supported the approval, demonstrating the utility of the test in stratifying patients and guiding treatment with Zejula, an oral PARP inhibitor that works by disrupting DNA repair mechanisms in cancer cells. Approximately 50% of patients with advanced ovarian cancer are HRD-positive, making accurate detection essential for optimizing treatment strategies.
The test has also been recognized in clinical guidelines, further emphasizing its role in standard-of-care decision-making for ovarian cancer treatment.
Strengthening the Role of Companion Diagnostics in Oncology
The approval underscores the growing integration of diagnostics and therapeutics in modern oncology, where companion diagnostics are essential for enabling precision medicine approaches. By linking diagnostic testing directly to therapeutic selection, healthcare providers can deliver more targeted and effective treatments, reducing unnecessary exposure to ineffective therapies.
Myriad Genetics continues to lead in the field of molecular diagnostics and genomic testing, providing tools that support early detection, risk assessment, and personalized treatment planning. The MyChoice CDx test represents a key component of this strategy, helping to bridge the gap between genomic insights and clinical application.
Advancing Precision Medicine in Ovarian Cancer
Ovarian cancer remains a serious and often difficult-to-treat disease, with many patients experiencing recurrence despite initial therapy. The integration of HRD testing and PARP inhibitor therapy represents a major advancement in improving patient outcomes.
By enabling accurate identification of patients with HRD-positive tumors, the MyChoice CDx test supports the use of Zejula as a maintenance therapy, helping to prolong disease control and improve survival outcomes. This approach reflects the broader shift toward personalized oncology, where treatment decisions are guided by molecular characteristics of the disease rather than a one-size-fits-all strategy.
The FDA approval of this companion diagnostic highlights the importance of robust clinical validation, regulatory compliance, and adherence to GxP standards, ensuring that both diagnostic tools and associated therapies meet the highest standards of safety and efficacy.
Source: Myriad Genetics press release
