PALO ALTO, Calif. — October 8, 2026

Guardant Health, Inc. announced that its Guardant360 CDx liquid biopsy test has received CE marking under the European Union’s In Vitro Diagnostic Medical Devices Regulation (IVDR) as a companion diagnostic for AstraZeneca’s ETCAMAH (camizestrant). The test is intended to identify patients with estrogen receptor-positive (ER-positive), HER2-negative locally advanced or metastatic breast cancer whose tumors carry ESR1 mutations. The milestone represents Guardant Health’s 31st companion diagnostic approval.

Blood-Based Testing Supports Treatment Selection

Guardant360 CDx enables clinicians to assess tumor-associated genomic alterations through a blood draw, helping identify ESR1 mutations that may inform treatment decisions before disease progression. This liquid biopsy approach offers a less invasive method of obtaining molecular information than tissue-based testing in appropriate clinical settings. The European authorization follows previous companion diagnostic approvals for ETCAMAH in the United States and Japan.

Companion Diagnostic Links Testing With Targeted Therapy

ETCAMAH (camizestrant), developed by AstraZeneca, is a next-generation oral selective estrogen receptor degrader (SERD) and complete estrogen receptor antagonist. The companion diagnostic is designed to help determine which eligible patients with advanced breast cancer may benefit from treatment based on their tumor’s ESR1 mutation status. The approval underscores the role of biomarker testing in supporting personalized oncology treatment strategies.

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Guardant Health Expands Precision Oncology Platform

Guardant Health develops blood- and tissue-based tests, real-world data solutions and artificial intelligence analytics to support cancer screening, recurrence monitoring and treatment selection. Guardant360 CDx detects multiple genomic alterations across solid tumors and has companion diagnostic applications in several cancer types. The latest European approval expands its regulatory reach and strengthens the company’s precision oncology portfolio.

Source::Guardant Health press release