A Study Comparing Savolitinib Plus Osimertinib vs Savolitinib Plus Placebo in Patients With EGFRm+ and MET Amplified Advanced NSCLC

Resistance to EGFR-TKIs is a clinical problem. One of the mechanisms for resistance to osimertinib is amplification of the MET receptor tyrosine kinase, which activates downstream intracellular signalling independent of EGFR. This study will explore the individual contribution of savolitinib to MET mediated osimertinib resistance, by assessing the response to dual pathway blockade of EGFRm and MET to overcome MET mediated resistance to osimertinib versus inhibition of the MET pathway alone by investigating the efficacy of savolitinib plus osimertinib versus savolitinib plus placebo to osimertinib (hereafter referred to as placebo) in patients with EGFRm+ and MET amplified, locally advanced or metastatic NSCLC who have progressed following treatment with osimertinib. This is a multi centre, Phase II, double blind, randomised study. Patients will be randomised in a ratio of 1:1 to receive treatment with savolitinib once daily plus osimertinib once daily or savolitinib once daily plus placebo. Randomisation will be stratified according to the number ofprior lines of therapy (ie, osimertinib monotherapy as first line or ≥ second line \[which includes patients who received osimertinib monotherapy before or after chemotherapy\]). All patients confirmed as eligible will begin treatment on Day 1 with savolitinib plus osimertinib or savolitinib plus placebo. Treatment will continue once daily in 28 day cycles until either objective PD by RECIST 1.1 is assessed, unacceptable toxicity occurs, consent is withdrawn, or another discontinuation criterion is met. After progression, patients can be unblinded, and patients initially randomised to the savolitinib plus placebo arm may cross-over to open-label savolitinib plus osimertinib following investigator assessed objective PD to ensure that all patients enrolled may have the opportunity to receive the combination of savolitinib plus osimertinib.