First-line gefitinib in patients with advanced non-small-cell lung cancer harboring somatic EGFR mutations.
OBJECTIVE
Somatic mutations in the epidermal growth factor receptor (EGFR) correlate with increased response in patients with non-small-cell lung cancer (NSCLC) treated with EGFR tyrosine kinase inhibitors (TKIs). The multicenter iTARGET trial prospectively examined first-line gefitinib in advanced NSCLC patients harboring EGFR mutations and explored the significance of EGFR mutation subtypes and TKI resistance mechanisms.


METHODS
Chemotherapy-naïve patients with advanced NSCLC with >or= 1 clinical characteristic associated with EGFR mutations underwent direct DNA sequencing of tumor tissue EGFR exons 18 to 21. Patients found to harbor any EGFR mutation were treated with gefitinib 250 mg/d until progression or unacceptable toxicity. The primary outcome was response rate.


RESULTS
Ninety-eight patients underwent EGFR screening and mutations were detected in 34 (35%). EGFR mutations were primarily exon 19 deletions (53%) and L858R (26%) though 21% of mutation-positive cases had less common subtypes including exon 20 insertions, T790M/L858R, G719A, and L861Q. Thirty-one patients received gefitinib. The response rate was 55% (95% CI, 33 to 70) and median progression-free survival was 9.2 months (95% CI, 6.2 to 11.8). Therapy was well tolerated; 13% of patients had grade 3 toxicities including one grade 3 pneumonitis. Two patients with classic activating mutations exhibited de novo gefitinib resistance and had concurrent genetic anomalies usually associated with acquired TKI resistance, specifically the T790M EGFR mutation and MET amplification.


CONCLUSIONS
First-line therapy with gefitinib administered in a genotype-directed fashion to patients with advanced NSCLC harboring EGFR mutations results in very favorable clinical outcomes with good tolerance. This strategy should be compared with combination chemotherapy, the current standard of care.
Sequist
Lecia V
LV
Massachusetts General Hospital Cancer Center, 32 Fruit St, Yawkey Suite 7B, Boston, MA 02114, USA. lvsequist@partners.org
Martins
Renato G
RG
Spigel
David
D
Grunberg
Steven M
SM
Spira
Alexander
A
Jänne
Pasi A
PA
Joshi
Victoria A
VA
McCollum
David
D
Evans
Tracey L
TL
Muzikansky
Alona
A
Kuhlmann
Georgiana L
GL
Han
Moon
M
Goldberg
Jonathan S
JS
Settleman
Jeffrey
J
Iafrate
A John
AJ
Engelman
Jeffrey A
JA
Haber
Daniel A
DA
Johnson
Bruce E
BE
Lynch
Thomas J
TJ
D000230:Adenocarcinoma / Q000188:drug therapy / Q000235:genetics / Q000556:secondary; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D018287:Carcinoma, Large Cell / Q000188:drug therapy / Q000235:genetics / Q000556:secondary; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy* / Q000235:genetics / Q000556:secondary; D016543:Central Nervous System Neoplasms / Q000188:drug therapy / Q000235:genetics / Q000556:secondary; D018572:Disease-Free Survival; D066246:ErbB Receptors / Q000037:antagonists & inhibitors / Q000235:genetics*; D005260:Female; D000077156:Gefitinib; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics*; D009367:Neoplasm Staging; D011446:Prospective Studies; D011799:Quinazolines / Q000627:therapeutic use*; D015996:Survival Rate; D016896:Treatment Outcome
D000970:Antineoplastic Agents; D011799:Quinazolines; D066246:ErbB Receptors; D000077156:Gefitinib