PURPOSE: Anaplastic lymphoma kinase (ALK) dysregulation is implicated in numerous cancers. Tyrosine kinase inhibitors (TKIs) targeting ALK have improved disease outcomes, but resistance mechanisms are common. This first-in-human trial evaluates ESK-440, a dual inhibitor of ALK and focal adhesion kinase, as a novel strategy for cancers with resistance to ALK-targeting TKIs. METHODS: This phase 1, open-label, dose-finding study evaluated the maximum tolerated dose (MTD), safety, efficacy, and pharmacokinetics of ESK-440 in participants with advanced or metastatic solid tumors (ClinicalTrials.gov: NCT01922752). A 3 + 3 dose-escalation design, with daily doses ranging from 25 to 700 mg/day of ESK-440 for each 28-day treatment cycle (6 to 8 cycles) was utilized to identify the MTD. A phase 1b was planned to further evaluate ESK-440 safety and antitumor activity at the MTD but was not performed due to sponsor decision. RESULTS: 32 participants were enrolled and 24 (75 %) completed cycle 1 of treatment. Three dose-limiting toxicities, all grade 3 nausea, were reported (n = 1, 500 mg
n = 2, 700 mg). The MTD was determined to be 500 mg daily. The most frequent adverse events (AEs) were fatigue and nausea (53 % each) and vomiting (38 %). Seven participants (22 %) withdrew from treatment due to AEs and 4 deaths occurred, none related to ESK-440. No participant had a complete or partial response
the best overall response was stable disease in 7 participants. CONCLUSIONS: ESK-440 was safe and tolerable with a maximum tolerated dose of 500mg daily
however, the study was terminated early based on sponsor decision.