INTRODUCTION: Preclinical evidence suggests the feedforward cytokine loop of interleukin-6/Janus kinases (JAK)/STAT3 plays a role in epidermal growth factor receptor tyrosine kinase inhibitor (EGFR TKI) resistance in EGFR-mutated non-small cell lung cancer (NSCLC).METHODS: In this phase 1b study, the JAK1/2 and TANK-binding kinase 1 (TBK1) inhibitor momelotinib was evaluated in combination with erlotinib in patients with EGFR TKI-naive, EGFR-mutated NSCLC. After erlotinib lead-in (50, 75, 100, or 150mg oral daily [QD]), momelotinib was combined and dose escalated in a 3+3 study design. The primary endpoint of maximum tolerated dose (MTD) of momelotinib was determined based on the incidence of dose-limiting toxicities (DLTs) during the first 28-day cycle. Secondary endpoints included efficacy and pharmacokinetics (PK).RESULTS: Eleven patients were enrolled across 3 dose levels of momelotinib (100mg QD, 200mg QD, and 100mg twice daily [BID]). The MTD was momelotinib 200mg QD in combination with erlotinib. Two DLTs of grade 4 neutropenia without fever and grade 3 diarrhea occurred at momelotinib 100mg BID. Most common treatment-emergent adverse events included diarrhea, dry skin, fatigue, and decreased appetite; the vast majority being grades 1-2. The overall response rate was 54.5% (90% CI 27.1-80.0; all partial) and median progression-free survival was 9.2months (90% CI 6.2-12.4). Momelotinib did not affect the PK of erlotinib.CONCLUSIONS: The JAK1/2 and TBK1 inhibitor momelotinib in combination with erlotinib did not appear to enhance benefit over the historical data of erlotinib monotherapy in patients with EGFR-mutated NSCLC. CLINICALTRIALS.GOV IDENTIFIER: NCT02206763.
View details for DOI 10.1007/s00280-021-04369-0
View details for PubMedID 34773474