A phase I, open-label, multicenter, first-in-human study of the safety, tolerability, pharmacokinetics, and antitumor activity of TPX-0022, a novel MET/CSF1R/SRC inhibitor, in patients with advanced solid tumors harboring genetic alterations in MET.

Abstract

TPS3663 Background: Alterations in the MET gene, including amplifications, chromosomal translocations, and activating mutations (kinase domain [KD] or exon 14 [Δex14]), occur across various tumors and may function as oncogenic drivers. SRC family kinases function as a key downstream node for MET signaling. CSF1R is a receptor tyrosine kinase associated with tumor progression and suppression of the immune response in the tumor microenvironment. TPX-0022 is a type I kinase inhibitor with a novel macrocyclic structure that potently inhibits MET, CSF1R and SRC to simultaneously target oncogenic MET signaling, its key downstream mediators, and the tumor microenvironment. Methods: This is a multicenter phase 1 first-in-human, open-label study to determine the safety, tolerability, PK, and preliminary efficacy of TPX-0022 in adults with advanced solid tumors harboring genetic alterations in MET. TPX-0022 will be administered orally in continuous 28-day cycles. The primary endpoint is the incidence of DLTs and determination of recommended phase 2 dose (RP2D). Secondary endpoints include ORR by blinded independent central review, intra-cranial response rate, PFS and OS (dose expansion only). In the dose escalation portion, ~30 subjects age ≥18 with solid tumors harboring MET gene amplifications, Δex14, fusions or KD mutations as determined by local tissue-based or liquid biopsy will be enrolled in a 3+3 design. Intrasubject dose escalation will also be allowed. Once the RP2D has been determined, a food effect sub-study will be conducted and ~80 subjects will be enrolled in a dose expansion portion of the study into the following cohorts: I: non-small cell lung cancer (NSCLC) Δex14 (MET therapy naïve), II: NSCLC Δex14 (MET therapy pre-treated), III: MET amplified NSCLC, gastric, or hepatocellular carcinoma, IV: solid tumors with MET KD mutations or fusions. Correlative studies will include analysis of circulating cell-free DNA to identify genomic alterations that may predict activity of TPX-0022 as well as circulating protein biomarkers such as s-MET, HGF, CSF1 and serum cytokines. The study is open and enrolling in the dose escalation portion at the time of submission. Clinical trial information: NCT03993873 .