Capmatinib efficacy in patients with NSCLC identified as METex14 using an NGS-based liquid biopsy assay: Results from the GEOMETRY mono-1 study.
Authors: Heist Rebecca Suk , Garon Edward B. , Tan Daniel Shao-Weng , Groen Harry J.M. , Seto Takashi , Smit Egbert F. , Zou Mike R. , Yang Yiqun , Li Ying , Chassot-Agostinho Andrea , Wolf Juergen 
Published: June 2021

9111 Background: Capmatinib, a highly selective and potent MET inhibitor, was approved for patients (pts) with advanced MET exon 14 skipping mutation (METex14) NSCLC in the US and Japan, with the FoundationOne CDx (tissue NGS assay), based on results of the ongoing GEOMETRY mono-1 study (NCT02414139). Here, we report efficacy findings in pts from GEOMETRY mono-1, who were identified as METex14 using a next-generation sequencing (NGS)-based liquid biopsy test (LDx), which detects METex14 in circulating tumor (ct)DNA. Methods: During the GEOMETRY mono-1 study, pts were screened for METex14 status using a METex14 RT-PCR clinical trial assay (CTA) on FFPE tissue. Clinical validation of the LDx was performed using plasma samples from pts enrolled in the GEOMETRY mono-1 study, which include METex14-positive samples from Cohort (C)4 (pretreated) and C5b (treatment-naïve), in addition to METex14-negative samples from C1b, C2, and C3, and 21 tissue-matched NSCLC plasma samples from commercial sources to supplement the total number of METex14 deletion negative patients. Concordance of the CTA and LDx were evaluated by positive percent agreement (PPA) and negative percent agreement (NPA). This retrospective analysis reports overall response rate (ORR), duration of response (DOR), and progression-free survival (PFS), all by BIRC, and overall survival (OS) in pts identified as METex14 by the LDx (data cutoff: Sep 18, 2020). Results: Of the 97 pts with METex14 NSCLC in C4 (n = 69) and C5b (n = 28), 88 pts had plasma volume ≥2.5 mL and cell free DNA ≥20 ng (minimum input); of these 57 were LDx positive (C4, n = 41; C5b, n = 16), 26 were negative; 5 had invalid sequencing results. Of the 97 CTA METex14-negative patients who met minimum input requirements, 88 were LDx negative and 9 had invalid sequencing results; none of the CTA METex14-negative pts (N = 97) were reported as positive by the LDx. The PPA and NPA for these were 68.7% (95% CI: 57.6%, 78.4%) and 100% (95% CI: 95.9%, 100%), respectively, when excluding LDx invalid results. In pts identified as METex14 positive by LDx, the ORR (95% CI) was 81.3% (54.4‒96.0; n = 16) in C5b and 48.8% (32.9‒64.9; n = 41) in C4; median DOR (95% CI) was 20.3 (4.2, NE; n = 13) months in C5b and 9.8 (4.2‒19.5; n = 20) months in C4; median PFS (95% CI) was 12.4 (4.5‒NE; n = 16) months in C5b and 5.4 (4.0‒6.6; n = 41) months in C4; median OS was 17.9 (9.8‒NE; n = 16) months in C5b and 13.6 (6.6‒23.3; n = 41) months in C4. Clinical findings in those identified as METex14 positive by LDx were comparable with those identified by the CTA. Conclusions: Current findings from the GEOMETRY mono-1 study support the activity of capmatinib in advanced NSCLC pts with METex14 identified using LDx. For pts identified as METex14-negative by the LDx, further testing should be performed on tissue samples, as a negative LDx result does not preclude a positive result by tissue biopsy. Clinical trial information: NCT02414139.