ECOG-ACRIN 5162: A phase II study of osimertinib 160 mg in NSCLC with EGFR exon 20 insertions.
Abstract No : 9513
Abstract Type : Poster Discussion Session
Indication : NSCLC with EGFR exon 20 insertions
Intervention : Osimertinib
Company : U.S. National Institutes of Health
Technology : Small molecule
Results: 21 pts were enrolled between 4/2018 and 7/2019 (median age 65; 15 female, 6 male; median 2 prior therapies); 1 patient did not meet eligibility criteria due to laboratory studies obtained 1 day out of window. As of 1/21/20, 6 pts remain on treatment. Among the 20 eligible pts, the best response was PR in 4 pts and CR in one pt, for a confirmed ORR of 25%; 12 (60%) pts had SD. The median PFS was 9.7 months (95% CI, 4.07, NA), median duration of response (DOR) was 5.7 months (95% CI, 4.73, NA.) Grade . 3 treatment-related adverse events (TRAE) observed in . 1 pt included anemia (n=2), fatigue (n=2), prolonged QT interval (n=2.) One pt had grade 4 respiratory failure, there were no grade 5 TRAEs. One pt discontinued study treatment due to grade 3 anemia.
Osimertinib 160mg daily is well-tolerated and showed clinical activity in EGFR ins20-mutant NSCLC with a response rate of 25%, disease control rate of 85%, and mPFS of 9.7 months. The adverse events with osimertinib 160 mg QD in this cohort were consistent with other reports of this regimen; grade 3 rash and diarrhea were not observed.
Osimertinib has now also shown activity in NSCLC patients with EGFR exon 20 insertions which comprise 4-10% of EGFR-mutant NSCLC. Osimertinib is already approved in NSCLC patients with exon 19 deletions or exon 21 L858R mutations.