Dr. Heather Wakelee on What to Do When Resistance to EGFR TKIs Emerges

Heather Wakelee, MD associate professor of Medicine (Oncology) at Stanford University Medical Center, discusses treating EGFR-mutant patients with lung cancer who are resistant to EGFR tyrosine kinase inhibitors (TKIs).

Patients who have active EGFR-mutated lung cancer typically respond well to first- or second-generation TKIs. However, resistance often develops for these patients after 9 to 12 months on average, says Wakelee. For 50% to 60% of patients, that resistance occurs due to T790M, a resistance mutation that develops within EGFR, she says.

It is important to identify that mutation when it develops. This can be done using standard tissue biopsies, but there are also more novel methods that utilize circulating tumor DNA as well as urine tests, says Wakelee. If the T790M mutation can be identified, patients may be able to receive osimertinib, a third-generation TKI that works in the majority of patients with T790M resistance.