A phase Ia/IIa trial of Sym015, a MET antibody mixture, in patients with advanced solid tumours

Abstract

Background: MET gene amplification/mutation is implicated in oncogenesis of many tumor types. Sym015 is a recombinant antibody (Ab) mixture containing 2 humanized Abs binding non-overlapping epitopes on MET which has superior preclinical activity compared to other MET Abs. Here we present interim results from the First in Human study of Sym015. Method(s): In part 1 dose escalation, Sym015 was evaluated on every 2-week (q2w) schedule at 6/12/18/24 mg/kg doses in late line advanced solid tumor patients (pts). Based on PK/PD assessment, 18 mg/kg loading dose followed by 12 mg/kg q2w was selected as RP2D. The on-going Part 2 Dose expansion enrolls pts with MET amplification (METAmp >5 MET copies by Next Generation Sequencing (NGS) or FISH MET/CEP7 ratio >2.2 updated to >= 3.0) and/or MET exon 14 deletion (METEx14DELTA) positive tumors. Central FISH confirmation of tumor MET status and longitudinal circulating tumor (ct)DNA profiling is performed. Result(s): By April 2019, 51 pts (median age 61 yrs) have been treated, 12 pts in Part 1 and 39 pts in Part 2, the majority are non small cell lung cancer (NSCLC; 14 pts; 6 METAmp,7 METEx14DELTA, 1 both) and gastric cancer (GC; 12 METAmp pts). Treatment-related adverse events (TRAE) occurred overall in 41,2%; TRAE >= gr3 in 9,8% (edema, colitis, septic shock, hypoalbuminemia, hypophosphatemia, increased amylase). No pts discontinued or died due to TRAE. The most common TRAE of >= 5% were fatigue 15.7%, peripheral edema 7,8%, nausea, decreased appetite, pruritus and abdominal pain reported by 5.9% of pts each. The table shows preliminary efficacy in NSCLC patients. Sym015 PK was slightly non-linear, with a dose-dependent t1/2 of 7-10 days for the first dose. 83% METAmp concordance (10/12 samples) between tumor and blood was observed. [Table presented] Conclusion(s): Sym015 was well tolerated with early evidence of antitumor activity. Predictive biomarker analysis is underway. The study continues to enroll NSCLC patients with METAmp and/or METEx14DELTA. MET screening in blood seems feasible and may be included in future trials. Clinical trial identification: NCT02648724. Legal entity responsible for the study: Symphogen A/S. Funding(s): Symphogen A/S. Disclosure: D.R. Camidge: Advisory / Consultancy: 2019: Takeda, CBT Pharmaceuticals, Daiichi-Sankyo (ILD adjudication committee), G1 Therapeutics (DSMB), Bio-Thera (DSMB), Blueprint; Advisory / Consultancy: 2018: AstraZeneca, Takeda, Arrys/Kyn, Regeneron, Hengrui, G1 Therapeutics (DSMB), Daiichi Sankyo (ILD adjudication committee), Hansoh (SRC), Bio-Thera (DSMB), Ribon, BMS, Blueprint, Roche/Genentech, Inivata; Advisory / Consultancy: 2017: Genoptix, G1 Therapeutics (DSMB), Mersana Therapeutics, Roche/Genentech, Takeda, Ignyta, Daiichi Sankyo (ILD adjudication committee), Hansoh SRC, Bio-Thera DSMB, Lycera, Revolution Med; Research grant / Funding (self), Research grant / Funding (institution): 2017: Takeda Investigator-initiated Trial; Research grant / Funding (self), Research grant / Funding (institution), Company Sponsored Trials at Institution: 2018/9: AbbVie, AstraZeneca, BMS, Hansoh, Lycera, MedImmune, Merck, Pfizer, Phosplatin, Roche/Genentech, Seattle Genetics, Symphogen, Takeda. F. Janku: Research grant / Funding (self): Novartis, Genentech, BioMed Valley Discoveries, Astellas, Agios, Plexxikon, Deciphera, Piqur, Symphogen, Bristol-Myers Squibb, Asana, Upsher-Smith Laboratories; Advisory / Consultancy: Guardant Health, IFM Therapeutics, Synlogic, Deciphera; Advisory / Consultancy, Shareholder / Stockholder / Stock options: Trovagene; Advisory / Consultancy: Immunomet. D.V. Catenacci: Honoraria (self), Advisory / Consultancy: Merck, BMS, Lilly, Astellas, Gritstone, Taiho, Five Prime, Genentech Roche, Foundation Medicine, Guardant Health, Tempus. H.C. Chung: Honoraria (self): Merck-Serono, Lilly, Foundation Medicine; Advisory / Consultancy: Taiho, Celltrion, MSD, Lilly,Quintiles, BMS, Merck-Serono; Research grant / Funding (institution): Lilly, GSK, MSD, Merck-Serono, BMS-ONO, Taiho. A. Dowlati: Advisory / Consultancy: Seattle genetics, Takeda, AbbVie; Research grant / Funding (institution): Takeda, Taiho, Roche, EMD Serono, Bayer, Tesaro, Regeneron, Amgen, Mirati, BMS. K.S. Rohrberg: Research grant / Funding (institution), Travel / Accommodation / Expenses: Roche; Research grant / Funding (institution): Loxo Oncology, Orion Pharma, Pfizer, PUMA, Cantargia, Genmab, Novartis, Incyte, Bayer, AstraZeneca, Alligator, Merck, BMS; Travel / Accommodation / Expenses: Sanofi; Research grant / Funding (institution): Symphogen. T.T. Poulsen: Full / Part-time employment: Symphogen A/S. H. Rudbaek: Full / Part-time employment: Symphogen A/S. L. Alifrangis: Full / Part-time employment: Symphogen A/S. R.P. Dalal: Full / Part-time employment: Symphogen A/S. All other authors have declared no conflicts of interest.Copyright © 2019 European Society for Medical Oncology