NSCLC with MET exon 14 skipping mutation (METex14) is associated with poor outcomes. Integration of novel targeted therapies is challenging because of barriers in testing and drug access. We, therefore, sought to characterize the treatment patterns, outcomes, and emerging issues of treatment sequencing in patients with METex14-mutant NSCLC. We reviewed all NSCLC cases with METex14 alterations between 2014 and 2020 across four Canadian cancer centers. Demographics, disease characteristics, systemic therapy, overall response rates (ORRs), survival, and toxicity were summarized. Among 64 patients with METex14-mutant NSCLC, the median overall survival was 23.1 months: 127.0 months in stage 1, 27.3 months in resected stage 2 and 3, and 16.6 months in unresectable stage 3 or 4 disease, respectively. In patients with advanced disease, 22% were too unwell for systemic treatment. MET tyrosine kinase inhibitors (TKIs) were administered to 28 patients with an ORR of 33%, median progression-free survival of 2.7 months, and 3.8 months for selective TKIs. Programmed cell death protein-1 (PD-1) inhibitors were given to 25 patients—the ORR was 44% and progression-free survival was 10.6 months. No responses were seen with subsequent MET TKIs after initial TKI treatment. Grade 3 or higher toxicities occurred in 64% of patients who received MET TKI after PD-1 inhibitors versus 8% in those who did not receive PD-1 inhibitors. Many patients with advanced METex14 NSCLC were too unwell to receive treatment. PD-1 inhibitors seem effective as an initial treatment, although greater toxicity was seen with subsequent MET TKIs. Thus, timely testing for METex14 skipping and initial therapy are imperative to improving patient survival.

Background: Liver metastases (LM) in advanced non-small-cell lung cancer (NSCLC) are associated with poor clinical outcomes. The tolerogenic immune microenvironment in the liver may contribute to inferior response to immune checkpoint inhibitors (ICIs). We hypothesized that the presence of LM may be associated with an expanded peripheral myeloid population, using the neutrophil-to-lymphocyte ratio (NLR) as a surrogate in patients treated with ICIs. Objectives: We evaluated the impact of LM and NLR on clinical outcomes in patients with advanced NSCLC treated with ICIs. Design: This was a retrospective analysis conducted at a single cancer center. Methods: We reviewed the records of 324 patients with advanced NSCLC treated with programmed death ligand-1 (PD-L1) inhibitors as monotherapy or in combination with cytotoxic T-lymphocyte antigen-4 (CTLA-4) inhibitors. Clinical outcomes, including progression-free survival (PFS) and overall survival (OS), were evaluated among patients with and without LM in NLR-High (NLR ⩾ 5) and NLR-Low (NLR < 5) subgroups. Results: Patients with LM had significantly higher median NLR compared to patients without LM (median 7.3 vs 4.5, p < 0.001). Patients with LM had significantly shorter median PFS (HR 1.54, p = 0.006) and median OS (HR 1.56, p = 0.014). Patients with LM who were NLR-High (LM+ NLR-H) had shorter median PFS and median OS (2.0 months and 5.4 months, respectively) compared to patients who had LM and were NLR-Low (LM+ NLR-L, median PFS 4.0 months and median OS 13.3 months). This trend was also observed within the PD-L1 > 50% subgroup. In 42 patients with evaluable response and LM, 25/42 (59.5%) of patients had concordant responses in the liver and extra-hepatic sites. Conclusion: Patients with LM who are NLR-High had the poorest clinical outcomes to ICI, and this appeared to be irrespective of PD-L1 status. Ongoing translational work will provide further insight into tumor myeloid subpopulations that may correlate with treatment resistance.