TAGRISSO (osimertinib)

TAGRISSO (osimertinib) is an EGFR TKI indicated for adult patients with locally advanced or metastatic EGFR T790M mutation-positive non-small cell lung cancer (NSCLC).1

Prescribing information

Testing for the T790M mutation

Test for EGFR T790M at the first sign of progression.

Incorporating both plasma-based and tissue-based tests into your practice may identify more patients with the EGFR T790M mutation.3
Example testing sequence: begin with a blood (plasma) ctDNA test: if negative, follow-up with a tissue test
Example testing sequence: begin with a blood (plasma) ctDNA test: if negative, follow-up with a tissue test

In the instance of a negative outcome, a follow-up biopsy is recommended due to the possibility of false negatives in plasma-based testing1,4

Plasma and tissue tests are complementary approaches when testing for the T790M mutation

Plasma-based (ctDNA) testing:

  • More rapid turnaround time3,5
  • Less invasive collection procedure3,5
  • May better reflect disease status (primary and metastatic sites)3,5
  • Due to differences in tumour biology, a negative plasma-based test may not provide conclusive results3
  • Plasma assays can vary in sensitivity,6 may yield false negative results;3 negative plasma tests should undergo a follow-up tissue biopsy1

Tissue-based testing:

  • Commonly performed and standardized testing method3
  • High sensitivity of the clinical test helps to identify patients with the mutations and may allow for identification of other resistance mechanisms7
  • Not all patients can receive a biopsy due to:3,5
  •                      o Performance status
                         o Tumour location
                         o The ability to obtain sufficient tumour material

  • There may be potential complications involved with the collection process3
  • Heterogeneity of the sample may cause identification issues3

ctDNA testing offers a specific and sensitive method to assess EGFR mutation status3,6

In the instance tumour tissue is not available, ctDNA testing offers an accurate method to assess mutation status.6

Percent agreement* of the cobas® plasma test with the cobas® tissue test,** % (95% CI)

Detection rate
Detection rate

Adapted from Wu YL et al. 2017.

* Positive and negative percent agreements used here as measures of test sensitivity and specificity, respectively, and calculated with invalid results excluded.6
** The cobas® test is a real-time PCR test for qualitative mutation detection with the EGFR gene.6
Patient numbers are those patients with tissue mutation-positive status excluding patients from China due to plasma sample export limitations.6