Performance of Idylla^™ RAS-BRAF mutation test for formalin-fixed paraffin-embedded tissues of colorectal cancer

The Biocartis Idylla^™ platform is a fully automated, real-time PCR-based diagnostic system. The Idylla^™ KRAS and NRAS-BRAF Mutation Tests have been developed for the qualitative detection of mutations in KRAS, NRAS and BRAF genes, facilitating the genomic profiling of patients with colorectal cancer. The aim of the present study was to evaluate clinical performances of these tests in Japan.

The RAS and BRAF mutation statuses of 253 formalin-fixed paraffin-embedded (FFPE) colorectal cancer tissues were analyzed using the Investigational Use Only Idylla^™ KRAS Mutation Test and the Idylla^™ NRAS-BRAF Mutation Test and an in vitro diagnostics (IVD) kit (MEBGEN RASKET^™-B kit).

The success rate for obtaining a valid mutational data without retest of the Idylla tests was 97.6% (247/253): 111 KRAS mutations (43.8%), 9 NRAS mutations (3.6%), and 36 BRAF V600E mutations (14.2%) were detected using the Idylla tests. Compared with the MEBGEN RASKET-B results, the positive concordance rate was 97.4%, the negative concordance rate was 95.7%, and the overall concordance rate was 95.3% (κ = 0.919, 95% CI 0.871-0.967). The average turnaround time to Idylla^™ KRAS and NRAS-BRAF Mutation Test was 5.6 working days (range: 3-11 days).

This result demonstrates a high concordance between the Idylla^™ KRAS and NRAS-BRAF Mutation Tests and an existing IVD kit. In this manner, the Idylla^™ mutation tests were validated for the detection of clinically significant KRAS, NRAS, and BRAF mutations in FFPE samples from colorectal cancer patients.