Tepotinib in patients with non-small cell lung cancer with high-level MET amplification detected by liquid biopsy: VISION Cohort B

High-level MET amplification (METamp) is a primary driver in ∼1%-2% of non-small cell lung cancers (NSCLCs). Cohort B of the phase 2 VISION trial evaluates tepotinib, an oral MET inhibitor, in patients with advanced NSCLC with high-level METamp who were enrolled by liquid biopsy. While the study was halted before the enrollment of the planned 60 patients, the results of 24 enrolled patients are presented here. The objective response rate (ORR) is 41.7% (95% confidence interval [CI], 22.1-63.4), and the median duration of response is 14.3 months (95% CI, 2.8-not estimable). In exploratory biomarker analyses, focal METamp, RB1 wild-type, MYC diploidy, low circulating tumor DNA (ctDNA) burden at baseline, and early molecular response are associated with better outcomes. Adverse events include edema (composite term; any grade: 58.3%; grade 3: 12.5%) and constipation (any grade: 41.7%; grade 3: 4.2%). Tepotinib provides antitumor activity in high-level METamp NSCLC (ClinicalTrials.gov: NCT02864992).

T-cell infiltration in matched samples from malignant pleural mesothelioma (MPM) during evolution of disease

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Background: MPM is an aggressive cancer associated with asbestos exposure. Chemotherapy has been a mainstay of therapy and recently immunotherapy has been associated with survival improvements. Chemotherapy and immunotherapy influence the tumor microenvironment and some reports have shown increased of TIL after chemotherapy in MPM. The purpose of this study was to determine dynamic changes in the tumor immune environment during mesothelioma evolution and after systemic therapies in paired samples. Methods: We examined 20 matched formalin-fixed paraffin embedded tissue samples from 10 patients (p) with MPM taken at diagnosis and at disease progression (follow-up), including untreated and treated with chemotherapy or immunotherapy. Tissue densities (number of cells/mm2) of key immune effector cells such as total lymphocytes (CD3), cytotoxic T cells (CD8), regulatory T cells (FOXP3) and monocytes/macrophages (CD163) were quantified by image analysis using multiplexed immunohistochemistry (IHC). PD-L1 expression in both tumor cells and immune cells was analysed by singleplex IHC and quantified using the CPS score. Results: Median age was 62 years (range 53-84), 7 p were male and all p presented epithelioid histology. Three matched samples belong to patients that did not receive any systemic treatment between biopsies and the other 7 pair of samples belong to patients treated with chemotherapy +/- immunotherapy. The median interval between paired biopsies was 12 m (3-33 m). Median overall survival was 27.8 months (1 m-NR). Median densities of T cells and macrophages in diagnostic and matched follow-up samples were: CD3+:982 vs 712; CD8+:422 vs 334, FOXP3+: 22 vs 25 and CD163+: 2086 vs 1706. Median PD-L1 CPS was 2.5 and 4 in diagnostic and follow-up samples, respectively. In p receiving treatment between sample pairs, the median densities in diagnostic and follow-up matched samples were: CD3+:979 vs 407; CD8+:467 vs 225, FOXP3+: 25 vs 15, CD163+: 1583 vs 1508, and PD-L1: 2 and 1. In p without any systemic treatment between sample pairs, the median densities were CD3+:1645 vs 2397; CD8+:376 vs 1605, FOXP3+: 19 vs 121, CD163+: 2102 vs 2377, and PD-L1: 3 vs 25. Conclusions: In our small series with paired samples from MPM p, we observed immune cells infiltration changes during MPM evolution with a trend towards a decrease after systemic therapy. Further investigation in tumor microenvironment in MPM to define the most appropriate time for immunotherapy is needed.

Clinical response to tepotinib according to circulating tumor (ct) DNA biomarkers in patients with advanced NSCLC with high-level MET amplification (METamp) detected by liquid biopsy (LBx)

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Background: Tepotinib, a potent, highly selective, oral, MET inhibitor, showed meaningful activity in patients (pts) with NSCLC with high-level METamp by LBx in VISION. Exploratory biomarker analyses are presented herein. Methods: Pts had 0–2 prior therapy lines, high-level METamp by LBx (Guardant360; MET copy number ≥2.5), and no MET exon 14 skipping or EGFR/ ALK alterations. Pts received tepotinib 500 mg once daily (450 mg active moiety). Primary endpoint was objective response by independent review; data cut-off: Aug 20, 2021. Exploratory biomarker analysis included LBx at baseline (BL), on treatment, and end of treatment (EOT). Early molecular response (eMR) was defined as undetectable METamp 6–8 weeks on treatment. Results: 24 pts were enrolled (median age: 63.4 years [yrs]; smokers: 88%; ECOG PS 1: 88%; adenocarcinoma: 67%). Treatment duration was ≥1 yr in five pts and ≥2 yrs in two pts (both ongoing). Overall, objective response rate (ORR) was 41.7% (95% CI: 22.1, 63.4). Treatment-naïve pts (n=7) had an ORR of 71.4% (29.0, 96.3), median (m) DOR was 14.3 months (2.8, not estimable [ne]), and mPFS was 15.6 months (1.4, ne). BL biomarker analyses according to clinical benefit (CR/PR/SD [n=11] vs PD/NE [n=13]) showed association with better outcomes in pts with focal METamp, or without MYCamp or RB1 mutation (Table). MYCamp/ RB1 mutation was detected in 4/7 pts with neuroendocrine/not otherwise specified histology; MYCamp in 2/3 pts with neuroendocrine histology. Low BL ctDNA mutant allele frequency (MAF) was associated with better outcomes. 14 pts had eMRs (ORR 71.4%); persistent METamp (n=4) was associated with lack of clinical response. 2/9 pts with EOT biomarker profiles had emerging resistance mechanisms (MET kinase domain mutations Y1230 and D1228); both had METamp re-emergence. Treatment-related adverse events included edema (composite term; any grade: 46%; Grade 3: 13%) and constipation (any grade: 17%; Grade ≥3: 0%). Conclusions: Tepotinib showed meaningful activity, especially in first line, in the first trial of a MET inhibitor in EGFR WT NSCLC with high-level METamp to enroll based on a convenient LBx assay. BL biomarker analyses indicated focal METamp, MYC/RB1 WT, and low ctDNA MAF were associated with improved outcomes. Serial LBx could monitor molecular response and evaluate resistance. Clinical trial information: NCT02864992. [Table: see text]

Tepotinib in patients (pts) with advanced non-small cell lung cancer (NSCLC) with MET amplification (METamp)

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Background: METamp is an oncogenic driver occurring in 1–5% of NSCLCs that confers a poor prognosis and lacks approved targeted therapies. Tepotinib, a highly selective MET inhibitor, provided durable response in NSCLC with MET exon 14 ( METex14) skipping in Cohort A of the Phase II VISION trial (NCT02864992). VISION Cohort B evaluated tepotinib in pts with advanced NSCLC and METamp, as detected by a convenient and minimally invasive liquid biopsy assay, in the absence of METex14 skipping. Methods: Pts with locally advanced or metastatic NSCLC, Eastern Cooperative Oncology Group performance status (ECOG PS) 0–1, 0–2 prior lines of therapy, EGFR/ ALK wild-type status, no METex14 skipping, and METamp by liquid biopsy (Guardant360®; MET gene copy number ≥2.5) received oral tepotinib 500 mg QD (450 mg active moiety). The primary endpoint was objective response (RECIST v1.1) by independent review committee (IRC). Secondary endpoints included duration of response (DOR), progression-free survival (PFS) and safety. The data cut-off was July 1, 2020. Results: Among 24 enrolled pts, median age was 63.4 years (range: 38–73), 21 pts (88%) were male, 21 (88%) had ECOG PS 1 and 21 (88%) were smokers. Tepotinib was given to 7 pts (29%) in first line (1L), 10 pts (42%) in second line (2L) and 7 pts (29%) in third line (3L). As of November 2020, treatment was ongoing for > 1 year in 5 pts (1L, n = 2; 2L, n = 2; 3L, n = 1). Objective response rate (ORR) by IRC was 42% (10/24 pts) overall, 71% (5/7 pts) in 1L, 30% (3/10 pts) in 2L and 29% (2/7 pts) in 3L (Table). Median DOR by IRC was not estimable (NE; 95% confidence interval [CI]: 2.8 months–NE). Investigator-assessed outcomes were similar. Five pts (20.8%) discontinued due to adverse events (AEs), which were considered unrelated to tepotinib. Treatment-related AEs were reported in 16 pts (67%; Grade 3/4, 7 pts [29%]) and included peripheral edema (9 pts [38%]; Grade 3/4, 2 pts [8%]), generalized edema (4 pts [17%]; Grade 3/4, 2 pts [8%]) and constipation (4 pts [17%]; Grade 3/4, 0 pts). Conclusions: In the first study of a MET inhibitor in NSCLC with METamp prospectively detected by liquid biopsy, tepotinib showed high and clinically meaningful activity, especially in 1L, and was generally well tolerated. Tepotinib warrants further evaluation in NSCLC with METamp. Clinical trial information: NCT02864992. [Table: see text]