A companion diagnostic is not just a test — it is a decision gate. Before a patient receives a targeted cancer therapy, a companion diagnostic confirms whether their tumour carries the biomarker that therapy depends on. Without it, the drug may be ineffective or harmful. As regulatory agencies worldwide mandate co-development of drugs and diagnostics, the companion diagnostics market has become one of the most structurally protected segments in laboratory medicine.

The market spans HER2, PD-1, EGFR mutation, and ALK rearrangement testing, delivered as assays and kits, instruments, and software and services, using PCR, next-generation sequencing, immunohistochemistry, and FISH technologies, serving pharmaceutical and biotechnology companies, CROs and CDMOs, and clinical laboratories. According to companion diagnostic market research, the market stood at approximately USD 9.32 billion in 2025 and is projected to reach USD 26.83 billion by 2035, growing at a CAGR of 11.15%. Assays and kits dominate product revenue at 70.80% share, while PCR retains the largest technology share at 23.50%. North America leads with a 43.15% revenue share, while Asia-Pacific is growing fastest at 13.45% CAGR.

Innovation is concentrated on NGS-based multiplex panels, liquid biopsy, and AI-powered interpretation platforms. Recent industry developments include FDA approval of FoundationOne CDx as a companion diagnostic for a KRAS G12C inhibitor and CMS Medicare coverage for the Shield blood test in colorectal cancer screening.

Challenges include IVDR compliance bottlenecks in Europe, reimbursement gaps in emerging markets, and pre-analytical variability in tissue handling.

Yet the fundamentals are strong: FDA co-development mandates create a guaranteed demand floor, and liquid biopsy is expanding testing into new populations. The market is expected to grow substantially.

People Also Ask

Q: How large is the companion diagnostics market?
A: It stood at approximately USD 9.32 billion in 2025 and is projected to reach USD 26.83 billion by 2035, growing at a CAGR of 11.15%.

Q: What is a companion diagnostic?
A: It is a test that identifies patients likely to benefit from a specific therapy by detecting a biomarker in tumour tissue or blood.

Tags: #CompanionDiagnostics #PrecisionOncology #Biomarkers #MolecularDiagnostics #CancerTesting #MarketResearch