GenesWell ddEGFR Mutation Test

Companion diagnostics for lung cancer

Companion Diagnostics?

Chemotherapy drugs have many side effects such as reduction in white blood cells, hair loss, vomiting because they attack rapidly growing cells without separating cancer cells from normal cells. However targeted therapy drugs have less side effects because they detect and attack specific targets that exist only in cancer cells.

  • Traditional Treatment
    • Prescribe various chemotherapy drugs sequentially without companion diagnostic test
  • Companion Diagnostics / Targeted therapy
    • A customized prescription based on genetic information of the patient
    • High treatment effects and fewer side effects

Companion diagnostics is an advanced diagnostic test that identifies the patient's genetic information and selects patients who are either effective in a particular treatment or unable to receive treatment due to the risk of severe abnormalities.

Digital PCR)

PCR(Polymerase Chain Reaction) techniques, which are techniques for amplifying/detecting genetic material, are consistently evolving. Especially ddPCR(digital droplet PCR)* technique, an advanced PCR platform, analyzes target genes after gene amplification with sample DNA partitioned across 20,000 droplets.

- Traditional PCR Droplet Digital PCR
Specificity Relatively low Relatively high
Sensitivity Relatively low Relatively high
Quantitative analysis Impossible Possible

* The kits are manufactured and sold under license from Bio-Rad.

Mutation Test

The GenesWell ddEGFR Mutation Test is a companion diagnostics which detects 45 EGFR mutations for non-small cell lung cancer(NSCLC) patients. It selects which NSCLC patients will respond to tyrosine kinase inhibitors such as Tarceva®(Erlotinib) and Tagrisso™(Osimertinib)

Detecting Mutations

Exon 18 Exon 19 Exon20 Exon 21
G719X E19del T790M S768I C797S E20ins L858R L861Q
3 30 1 1 2 5 2 1


  • DNA extraction from cancer tissue(FFPE)
  • GenesWell ddEGFR Mutation Test kit
  • ddPCR
  • Analysis software


  1. 01Selection of patients who need targeted anti-cancer therapy
  2. 02ddPCR platform with high sensitivity
  3. 03Available for low frequency(0.8%) mutations
  4. 04Software for automated result analysis


Droplet digital PCR-based EGFR mutation detection with an internal quality control index to determine the quality of DNA Kim. et al.
Scientific Reports | 2018
In clinical translational research and molecular in vitro diagnostics, a major challenge in the detection of genetic mutations is overcoming artefactual results caused by the low-quality of formalin-fixed paraffin-embedded tissue (FFPET)-derived DNA (FFPET-DNA). Here, we propose the use of an ‘internal quality control (iQC) index’ as a criterion for judging the minimum quality of DNA for PCR-based analyses. In a pre-clinical study comparing the results from droplet digital PCR-based EGFR mutation test (ddEGFR test) and qPCR-based EGFR mutation test (cobas EGFR test), iQC index ≥ 0.5 (iQC copies ≥ 500, using 3.3 ng of FFPET-DNA [1,000 genome equivalents]) was established, indicating that more than half of the input DNA was amplifiable. Using this criterion, we conducted a retrospective comparative clinical study of the ddEGFR and cobas EGFR tests for the detection of EGFR mutations in non-small cell lung cancer (NSCLC) FFPET-DNA samples. Compared with the cobas EGFR test, the ddEGFR test exhibited superior analytical performance and equivalent or higher clinical performance. Furthermore, iQC index is a reliable indicator of the quality of FFPET-DNA and could be used to prevent incorrect diagnoses arising from low-quality samples.