Safety and activity of WX-0593 (Iruplinalkib) in patients with ALK - or ROS1 -rearranged advanced non-small cell lung cancer: a phase 1 dose-escalation and dose-expansion trial

WX-0593 (Iruplinalkib) is a novel, highly selective oral ALK and ROS1 tyrosine kinase inhibitor (TKI). In this study, the safety, antitumor activity, and pharmacokinetics of WX-0593 were evaluated in advanced non-small cell lung cancer (NSCLC) patients with ALK or ROS1 rearrangement. In the dose-escalation phase and dose-expansion phase, patients were treated with WX-0593 until disease progression, unacceptable toxicity, or subject withdrawal. In the dose-escalation phase, the primary endpoints were maximum tolerated dose (MTD), dose-limiting toxicity (DLT), and safety assessed by investigators. In the dose-expansion phase, the primary endpoint was objective response rate (ORR) assessed by investigators. Between September 25, 2017 and October 15, 2018, a total of 153 patients received WX-0593 treatment. Two dose-limiting toxicities (DLTs) including one grade 3 QT interval prolonged and one grade 2 chronic heart failure were reported at the dose of 300 mg in one patient. MTD was not reached. Overall, 140 of the 152 (92%) patients experienced treatment-related adverse events (TRAEs) and 35 of the 152 (23%) patients had TRAEs ≥grade 3. The overall ORR was 59.3% (32 of 54) for the dose-escalation phase and 56.6% (56 of 99) for the dose-expansion phase. For patients who were ALK -rearranged and ALK TKI naive, the ORR were 81.0% (17 of 21) in the dose-escalation phase and 76.3% (29 of 38) in the dose-expansion phase, and for patients who previously received crizotinib as the only ALK TKI, the ORR were 38.1% (8 of 21) and 45.7% (21 of 46) for the two phases, respectively. For patients who were ROS1 -rearranged, the ORR were 30.0% (3 of 10) in the dose-escalation phase and 44.4% (4 of 9) in the dose-expansion phase. WX-0593 showed favorable safety and promising antitumor activity in advanced NSCLC patients with ALK or ROS1 rearrangement.