Find the Right Companion Diagnostic
Search by indication, biomarker, therapy, or test. Confirm which assay meets FDA requirements and see where it can be ordered, all in one place.
Featured Companion Diagnostics
Browse all →Oncomine Dx Target Test is an FDA-approved, qualitative targeted NGS assay performed on the Ion PGM Dx System. Using DNA and RNA from FFPE tumor tissue, it detects single-nucleotide variants, insertions, deletions, and fusions in a defined panel of cancer driver genes. It is approved for use in NSCLC and several other solid tumors to characterize oncogenic alterations and support selection of targeted treatment strategies.
MMR IHC Panel pharmDx is an FDA-approved, qualitative immunohistochemical assay performed on the Dako Omnis platform to assess MLH1, PMS2, MSH2, and MSH6 protein expression in FFPE colorectal cancer tissue. By determining mismatch repair–deficient (dMMR) status based on loss of nuclear staining, it helps identify patients who may be candidates for immunotherapy.
Idylla CDx MSI Test is an FDA-approved, fully automated real-time PCR assay that analyzes DNA from formalin-fixed, paraffin-embedded tumor tissue to qualitatively determine microsatellite instability (MSI) status. Performed on the Idylla cartridge-based system, it uses a panel of monomorphic markers and integrated analysis software to classify tumors as MSI-high or MSI-stable, supporting prognosis and treatment planning in eligible patients.
Explore by workflow
Start with a cancer type or clinical scenario (e.g., metastatic NSCLC), then see which biomarkers, therapies, and tests apply.
You know the biomarker you care about (EGFR, NTRK, HER2-low). See where it matters and which tests qualify.
Start from a specific drug and confirm the required biomarker and eligible companion diagnostics.
Already have a test in mind? Jump straight to its profile to see how and where it can be used.
Know Your Companions™
An intuitive report that maps indications, biomarkers, biomarker details, therapies, and eligible tests. Built from FDA approvals and CDx labeling.
| Indication | Biomarker | Biomarker details | Drug / therapy |
|---|---|---|---|
| Non-Small Cell Lung Cancer (NSCLC) | ALK | gene rearrangements | ALUNBRIG |
| Non-Small Cell Lung Cancer (NSCLC) | MET | MET protein expression (>= 50% of tumor cells exhibiting strong membrane and/or cytoplasmic staining 3+) | EMRELIS |
| Duchenne Muscular Dystrophy (DMD) | AAV Antibodies | serotype rh74 | ELEVIDYS |
View all 215 approvals and eligible tests.
Open Know Your Companions™ →For pharma teams
List your companion diagnostic on CDXtests.com to ensure it is discoverable, accurately represented, and easy for providers to find, understand, and order.
- • Single source of truth for your CDx
- • Clear therapy-to-test ordering pathways
- • Scalable infrastructure for launch and growth
For laboratories
If your lab performs an FDA-approved CDx or a validated LDT alternative, you can appear in provider workflows and support digital ordering through Casandra.
- • Be listed where providers search for companion diagnostics.
- • Connect to Casandra for streamlined ordering.
- • Align your offerings with Know Your Companions™ mapping.