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 →TruSight Oncology Comprehensive is a hybrid-capture, next-generation sequencing assay that analyzes DNA and RNA from FFPE solid tumors. It detects substitutions, insertions, deletions, copy number changes, and gene fusions across a broad set of cancer-related genes, and can report selected genomic signatures such as MSI or TMB to support comprehensive biomarker-driven treatment planning.
FDA-approved companion diagnostic for Muscle Invasive Bladder Cancer (MIBC)
PD-L1 IHC 28-8 pharmDx is an FDA-approved, qualitative immunohistochemical assay that uses monoclonal rabbit anti–PD-L1, clone 28-8, to detect PD-L1 protein in FFPE tumor tissue. Using the EnVision FLEX system on the Autostainer Link 48, it reports the percentage of tumor cells with membrane staining to classify PD-L1 expression and support PD-1/PD-L1–directed treatment decisions.
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 |
|---|---|---|---|
| Medullary Thyroid Cancer (MTC) | RET | RET mutations (SNVs, MNVs, and deletions) | RETEVMO |
| Thyroid Cancer (TC) | RET | fusions | RETEVMO |
| Muscle Invasive Bladder Cancer (MIBC) | Circulating tumor DNA (ctDNA) molecular residual disease (MRD) | ctDNA MRD | TECENTRIQ |
View all 240 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.