Tepotinib plus gefitinib in patients with MET-amplified EGFR-mutant NSCLC: Long-term outcomes of the INSIGHT study

Abstract Background In patients with EGFR-mutant NSCLC, MET amplification (METamp) is a resistance mechanism to EGFR tyrosine kinase inhibitors (TKI). In the randomized phase Ib/II INSIGHT study (NCT01982955) that halted full enrolment due to low recruitment, tepotinib (TEP), a potent, selective MET TKI, plus gefitinib (GEF) improved progression-free survival (PFS) and objective response rate (ORR) vs chemotherapy (CTx) in patients with EGFR-mutant NSCLC and resistance to 1st-line EGFR TKIs due to METamp (≥6-month follow-up). We now present long-term survival outcomes (≥18-month follow-up) for this predefined analysis. Methods Patients were randomized to TEP 500 mg + GEF 250 mg orally once daily (until progressive disease, intolerable toxicity or other withdrawal) or platinum + pemetrexed IV (≤6 x 21-day cycles). METamp was defined as GCN ≥5 and/or MET/CEP7 ratio ≥2. Primary endpoint was investigator-assessed (INV) PFS. Secondary endpoints included overall survival (OS), ORR, PFS by independent review (IRC), safety. Results From 04/24/15 to 06/12/17, 55 patients enrolled in the INSIGHT study and 19 were METamp (TEP+GEF 12; CTx 7); this predefined subgroup is analysed here. Median GCN was 8.8 (range 4.8–29.5); 18 patients had GCN ≥5, 13 had MET/CEP7 ratio ≥2. At data cutoff (12/12/18), median treatment duration (weeks [range]) for TEP+GEF was 49 (4.6–110.9; 3 patients still ongoing for ≥24 months), pemetrexed was 18.0 (5.9–60.4), cisplatin 12.0 (6.6–25.1) or carboplatin 12.8 (5.9–19.7), all CTx patients discontinued. TEP+GEF compared with CTx improved PFS (INV mPFS 21.2 vs 4.2 months, HR [90% CI] 0.13 [0.04, 0.43]; IRC mPFS 19.3 vs 5.5 months; 0.18 [0.06, 0.61]) and OS (mOS 37.3 vs 13.1 months, 0.08 [0.01, 0.51]), as well as ORR (INV 66.7 v 42.9%; OR 2.67 [0.37, 19.56]; IRC 75.0 vs 42.9%; OR 4.00 [0.51, 31.38]). Grade ≥3 treatment-related AEs in METamp patients (≥15% in either arm, TEP+GEF vs CTx) were amylase or lipase increased (both 33.3% vs 0%), anemia, neutrophil or WBC count decreased (all 0 vs 28.6%). Conclusions TEP+GEF improved survival of patients with EGFR TKI-resistant NSCLC due to METamp. TEP + osmertinib is currently being investigated in patients with METamp, EGFR-mutant NSCLC with acquired EGFR TKI resistance (NCT03940703). Clinical trial identification NCT01982955. Editorial acknowledgement Medical writing assistance was provided by Lisa Jolly, Bioscript, Macclesfield, UK, and funded by Merck KGaA, Darmstadt, Germany. Legal entity responsible for the study Merck KGaA, Darmstadt, Germany. Funding Merck KGaA, Darmstadt, Germany. Disclosure K. Park: Advisory / Consultancy: AstraZeneca, Boehringer Ingelheim, Clovis; Elli Lilly; Hanmi; ONO; Roche; Novartis. R.A. Soo: Honoraria (self): BMS, Celgene, Ignyta, Lilly, Merck, Novartis, Pfizer, Roche, Taiho, Takeda, Yuhan; Honoraria (self), Research grant / Funding (institution): AstraZeneca; Honoraria (self), Research grant / Funding (institution): Boehringer Ingelheim. R. Bruns: Full / Part-time employment: Merck KGaA. J. Straub: Full / Part-time employment: Merck KGaA. A. Johne: Full / Part-time employment: Merck KGaA. J. Scheele: Full / Part-time employment: Merck KGaA. J.C-H. Yang: Honoraria (self), Advisory / Consultancy: Boehringer Ingelheim, Eli Lilly, Bayer, Roche/Genentech/Chugai, MSD, Merck Serono, Pfizer, Novartis, Celgene, Merrimack, Yuhan Pharmaceuticals, BMS, Ono pharmaceutical, Daiichi Sankyo and AstraZeneca, Takeda Oncology, Blueprint Medicines, Hansoh Pharmaceu. Y-L. Wu: Honoraria (self), Advisory / Consultancy: AstraZeneca; Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution): Roche; Advisory / Consultancy, Research grant / Funding (institution): Boehringer Ingelheim ; Advisory / Consultancy: Merck; Honoraria (self): Eli Lilly, Pierre Fabre, Pfizer, Sanofi. All other authors have declared no conflicts of interest.