Targeting TIGIT in NSCLC—Is There Light on the Horizon?

Non-small cell lung cancers (NSCLCs) represent over 80% of all malignant lung tumours and are one of the leading causes of cancer death throughout the world. First- and second-line treatment of advanced or metastatic NSCLCs has changed dramatically during the last two decades with the development of novel immunotherapies (e.g., checkpoint inhibitors targeting PD-1, PD-L1, and CTLA-4) sparing NSCLC patients from the toxic effects of chemotherapy. However, only 15% - 20% of all patients respond to treatment. In order to improve response rates, experimental and clinical evidence has provided the basis for further evaluating the combination of co-stimulatory and inhibitory monoclonal antibodies to improve the anti-tumour immune response. Innovative second- and third-generation immuno-oncology drugs are currently evaluated in ongoing phase I-III trials (either alone or in combination) including the new checkpoint inhibitor target TIGIT (T cell immunoreceptor with Ig and ITIM domains). TIGIT functions as an inhibitory immunoglobin receptor which is overexpressed by different immune cells including effector and memory CD4+ T and CD8+ T cells, regulatory T cells (Tregs), follicular T helper cells (Tfh), and natural killer cells. Targeting the interaction between the receptors of the TIGIT receptors (e.g., CD96, CD112R, CD226, TIGIT and their corresponding binding partners) has become an innovative strategy for the next concepts of cancer immunotherapy that has the potential to synergize with PD-1/PD-L1checkpoint inhibition. Currently, four anti-TIGIT monoclonal antibodies are currently being studied in phase III trials in NSCLCs: 1) tiragolumab (SKYSCRAPER programme);2) vibostolimab (KEYVIVE programme);3) domvanalimab (ARC programme), and 4) ociperlimab (AdvanTIG programme). The vast majority of these studies are ongoing;however, the SKYSCRAPER-01 trial (tiragolumab in NSCLC) and the SKYSCRAPER-02 trial (tiragolumab in SCLC) were negative and did not meet their primary endpoint. The underlying preclinical and clinical mechanisms of these unexpectedly negative studies are currently far from being clear and the results from currently recruiting clinical studies are eagerly awaited to shed some additional light on these results. From 2021 onwards different TIGIT family receptors are currently evaluated in over 25 clinical trials (phase I-III), however, a lot of preclinical and clinical research is ongoing at different research sites which will help to identify novel immune checkpoint targets with improved activity against malignancies across all histologies.

C-MET Inhibitors as New Members of the NSCLC Treatment Armamentarium—A Pooled Analysis

Objective: Capmatinib and tepotinib, two recently FDA-approved and highly specific small-molecule inhibitors of c-MET exon 14 skipping mutations are new and important therapeutic options for the treatment of NSCLC patients harbouring c-MET alterations. However, the precise role of these molecules as a new treatment option is still not fully defined. Methods: In an attempt to further evaluate the contributions of c-MET inhibitors to the armamentarium of treatment options for advanced and metastatic NSCLCs, relevant phase II and III studies were retrospectively analyzed in terms of ORR and mPFS (mOS numbers are still not available for current c-MET trials and therefore not considered for statistical purposes). Results: Treatment of advanced and metastatic NSCLC patients harbouring c-MET exon 14 skipping mutations with the novel and highly selective c-MET inhibitors is significantly superior (p Conclusion: The novel and highly selective c-MET inhibitors capmatinib and tepotinib are promising novel treatment options for patients with c-MET-dysregulated NSCLC primarily in the first-line setting, albeit a clear mOS benefit has not yet been established. Since immunotherapy did not appear to be particularly effective in NSCLC patients harbouring c-MET alterations, the vast majority of these patients are treated with immunotherapy plus chemotherapy. C-Met inhibitors appear to be equally effective and thereby sparing patients from the toxic effects of the chemotherapy. The routine testing of c-MET exon 14 skipping mutations should be performed as the GEOMETRY mono-1 data clearly showed higher response rates with capmatinib in treatment-naive than in pretreated patients, indicating that c-MET exon 14 skipping mutations should preferably be molecularly assessed at baseline. C-MET exon 14 skipping mutations are, therefore, clear biomarkers of response to c-MET inhibitors.