Differentiated pharmacokinetic and pharmacodynamic properties of a highly selective MET kinase inhibitor, OMO-1: Implications for efficacy and safety

e14674 Background: The MET kinase is an established therapeutic target in a range of cancer indications, being a primary oncogenic and therapy resistance driver. Methods: OMO-1 is a highly potent, selective oral inhibitor of MET kinase and Organic Cation Transporter 2 (OCT2) that is currently being explored in a Phase I/II study (NCT03138083). Results: Pre-clinical data for OMO-1 indicates that anti-tumor efficacy against MET driven tumor models does not require 24/7 exposure in the plasma. PK/PD assessments indicate that OMO-1 efficacy is AUC driven. Exposures above a trough concentration of ~600ng/ml for a period of 6-8hr and an AUC of 3000ng.h/ml result in complete target inhibition sufficient to induce regression or stasis of MET driven in-vivo models. Dosing of OMO-1 at 12.5mg/kg BD 4hr apart, or split over 4 doses 2hr apart, with a dosing-free period of 18-20hr was sufficient to obtain the effects preclinically. The ongoing Phase I/II study in patients with solid tumours utilised learnings from the pre-clinical and FIH study (NCT01964872) where ascending single doses and multiple doses were evaluated. The selected starting dose for the patient study (100mg BD, 4 hr apart) achieved exposures above the predicted MBAD. Paired tumor biopsies were obtained from a higher dose level (200mg BD). A MET exon 14 skipping mutation NSCLC patient at this dosed demonstrated near-complete inhibition of phospho MET accompanied by signs of clinical benefit and lesion shrinkage, thereby matching the preclinical data. Certain ‘class effect’ adverse events, such as edema, were not observed. Conclusions: OMO-1 is an oral, potent MET TKI with a novel dosing regime, identified during preclinical optimization (BD 4hr apart), that demonstrates encouraging signs of clinical activity without certain ‘class-specific’ adverse events. Further evaluation of this differentiated and efficacious agent is warranted and ongoing.