Aims: We report the final analyses from the INSIGHT trial (NCT01982955; data cut-off: September 3, 2021; median follow-up: 57.5 months), which assessed the combination of tepotinib (a potent MET-TKI) and gefitinib versus chemotherapy in patients with EGFR-mutant NSCLC and resistance to anti-EGFR therapy due to MET amplification (METamp).
Methods: Patients with EGFR-mutant (T790M-negative) NSCLC and anti-EGFR resistance, with METamp (MET gene copy number [GCN] ≥5 and/or MET:CEP7 ≥2 by FISH) and/or MET overexpression (IHC 2+/3+), were randomized to tepotinib 500 mg (450 mg active moiety) + gefitinib 250 mg QD or chemotherapy. The primary endpoint was progression-free survival (PFS) per investigator assessment. Preplanned analyses evaluated patients with METamp.
Results: In 19/55 randomized patients (34.5%) with METamp (GCN ≥5, n=18; MET:CEP7 ≥2, n=13; MET IHC 3+, n=17), the median age was 60.4 years, 68.4% were never-smokers, and prior EGFR inhibitors were gefitinib (57.9%), afatinib (21.1%), erlotinib (10.5%), and icotinib (10.5%). The median duration of tepotinib + gefitinib treatment was 11.3 months (range: 1.1–56.5). Two patients continued treatment outside the study.
Tepotinib + gefitinib improved PFS (median 16.6 months [90% CI: 8.3, 22.1]) versus chemotherapy (median 4.2 months [90% CI: 1.4, 7.0]): HR 0.13 (90% CI: 0.04, 0.43). Overall survival (HR 0.10; 90% CI: 0.02, 0.36), objective response rate
(OR 2.67; 90% CI: 0.37, 19.56) and duration of response also improved with the combination in comparison to chemotherapy.
Treatment-related Grade ≥3 AEs occurred in seven patients (58.3%) with tepotinib + gefitinib and five (71.4%) with chemotherapy.
In patients with MET IHC 3+ (n=34, including 17 patients with METamp), tepotinib + gefitinib also markedly improved PFS (HR 0.35; 90% CI: 0.17, 0.74) and OS (HR 0.44; 90% CI: 0.23, 0.84) versus chemotherapy.
Conclusions: Tepotinib + gefitinib significantly improved PFS and OS versus chemotherapy in patients with EGFR-mutant NSCLC with METamp.