Aerobic glycolysis but not GLS1-dependent glutamine metabolism is critical for anti-tumor immunity and response to checkpoint inhibition.

Tumor cells undergo uncontrolled proliferation driven by enhanced anabolic metabolism including glycolysis and glutaminolysis. Targeting these pathways to inhibit cancer growth is a strategy for cancer treatment. Critically, however, tumor-responsive T cells share metabolic features with cancer cells, making them susceptible to these treatments as well. Here, we assess the impact on anti-tumor T cell immunity and T cell exhaustion by genetic ablation of lactate dehydrogenase A (LDHA) and glutaminase1 (GLS1), key enzymes in aerobic glycolysis and glutaminolysis. Loss of LDHA severely impairs expansion of T cells in response to tumors and chronic infection. In contrast, T cells lacking GLS1 can compensate for impaired glutaminolysis by engaging alternative pathways, including upregulation of asparagine synthetase, and thus efficiently respond to tumor challenge and chronic infection as well as immune checkpoint blockade. Targeting GLS1-dependent glutaminolysis, but not aerobic glycolysis, may therefore be a successful strategy in cancer treatment, particularly in combination with immunotherapy.

Insight into Targeting Exon20 Insertion Mutations of the Epidermal Growth Factor Receptor with Wild Type-Sparing Inhibitors.

Despite the clinical efficacy of epidermal growth factor receptor (EGFR) inhibitors, a subset of patients with non-small cell lung cancer displays insertion mutations in exon20 in EGFR and Her2 with limited treatment options. Here, we present the development and characterization of the novel covalent inhibitors LDC8201 and LDC0496 based on a 1H-pyrrolo[2,3-b]pyridine scaffold. They exhibited intense inhibitory potency toward EGFR and Her2 exon20 insertion mutations as well as selectivity over wild type EGFR and within the kinome. Complex crystal structures with the inhibitors and biochemical and cellular on-target activity document their favorable binding characteristics. Ultimately, we observed tumor shrinkage in mice engrafted with patient-derived EGFR-H773_V774insNPH mutant cells during treatment with LDC8201. Together, these results highlight the potential of covalent pyrrolopyridines as inhibitors to target exon20 insertion mutations.

Complex Crystal Structures of EGFR with Third-Generation Kinase Inhibitors and Simultaneously Bound Allosteric Ligands.

Osimertinib is a third-generation tyrosine kinase inhibitor (TKI) and currently the gold-standard for the treatment of patients suffering from non-small cell lung cancer (NSCLC) harboring T790M-mutated epidermal growth factor receptor (EGFR). The outcome of the treatment, however, is limited by the emergence of the C797S resistance mutation. Allosteric inhibitors have a different mode of action and were developed to overcome this limitation. However, most of these innovative molecules are not effective as a single agent. Recently, mutated EGFR was successfully addressed with osimertinib combined with the allosteric inhibitor JBJ-04-125-02, but surprisingly, structural insights into their binding mode were lacking. Here, we present the first complex crystal structures of mutant EGFR in complex with third-generation inhibitors such as osimertinib and mavelertinib in the presence of simultaneously bound allosteric inhibitors. These structures highlight the possibility of further combinations targeting EGFR and lay the foundation for hybrid inhibitors as next-generation TKIs.