A new generation of companion diagnostics: cobas BRAF, KRAS and EGFR mutation detection tests

Abstract

The cobas^® (Roche) portfolio of companion diagnostics in oncology currently has three assays CE-marked for in vitro diagnostics. Two of these (EGFR and BRAF) are also US FDA-approved. These assays detect clinically relevant mutations that are correlated with response (BRAF, EGFR) or lack of response (KRAS) to targeted therapies such as selective mutant BRAF inhibitors in malignant melanoma, tyrosine kinases inhibitor in non-small cell lung cancer and anti-EGFR monoclonal antibodies in colorectal cancer, respectively. All these assays are run on a single platform using DNA extracted from a single 5 µm section of a formalin-fixed paraffin-embedded tissue block. The assays provide an ‘end-to-end’ solution from extraction of DNA to automated analysis and report on the cobas z 480. The cobas tests have shown robust and reproducible performance, with high sensitivity and specificity and low limit of detection, making them suitable as companion diagnostics for clinical use.

Keywords::

• BRAF mutations
• cobas 480
• colorectal cancer
• companion diagnostics
• EGFR mutations
• KRAS mutations
• malignant melanoma
• molecular pathology
• non-small-cell lung cancer

Financial & competing interests disclosure

D Gonzalez has received honoraria from Roche Molecular Systems, Roche Products Ltd, AstraZeneca, Pfizer, Novartis, GSK, Boehringer Ingelheim and Amgen, and has received funding from AstraZeneca, Roche Molecular Systems, Roche Products Ltd and Merck-Serono. F Lopez-Rios has received honoraria from Roche Molecular Systems and has received funding from Roche Molecular Systems. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending or royalties.

No writing assistance was utilized in the production of this manuscript.

Key issues

• The cobas^® BRAF, KRAS and EGFR mutation detection kits provide high sensitivity and specificity for the detection of the most common mutations in the respective diseases from formalin-fixed paraffin embedded (FFPE) specimens.

• The cobas mutation kits are highly reproducible (>98%) in different clinical laboratories.

• The cobas mutation kits provide an end-to-end process, from DNA extraction of FFPE samples to automated analysis and reporting of the results.

• The cobas mutation kits allow for the reproducible detection of mutations in DNA containing <5% of mutant alleles.

• The level of multiplexing with the cobas mutation kits can reduce sample input and labor, while increasing throughput and speed, compared with other existing technologies.

• DNA extraction is performed using only a single 5 µm section of FFPE tissue, minimizing wastage of precious material.

• The cobas BRAF, KRAS and EGFR mutation kits are CE-marked for in vitro diagnostics use, and the cobas BRAF and EGFR kits are also US FDA-approved for in vitro diagnostics.

• Co-development of targeted therapies with the appropriate companion diagnostics are likely to become the norm in the development of personalized cancer medicine.

• Detection of genetic alterations other than mutational hotspots are needed for comprehensive molecular profiling of cancer and increasing number of biomarkers will be required in the near future. Therefore, single-platform, high-multiplex investigations will be needed.