Design and synthesis of 4th generation EGFR inhibitors against human triple (Del19/T790M/C797S) mutation

Fourth-generation EGFR-TKI to overcome C797S mutation: past, present, and future

Overactivation of the epidermal growth factor receptor (EGFR) is prevalent in various tumours, rendering it a promising target for cancer therapy, particularly in the treatment of non-small cell lung cancer (NSCLC). Although the first through third generations of EGFR tyrosine kinase inhibitors (TKIs) have demonstrated significant efficacy, the emergence of drug resistance continues to pose a challenge. Current research is now focused on fourth-generation EGFR-TKIs, which specifically target the EGFR harbouring the C797S mutation. This review examines the design strategies, antitumor activity both in vivo and in vitro, binding modes, pharmacokinetics, as well as the advantages and disadvantages of each inhibitor, alongside the progress of clinical stage research related to fourth-generation inhibitors. Additionally, the review discusses future development directions for fourth-generation EGFR-TKIs, aiming to provide insights for successful research and development in this field.

From challenges to solutions: A review of fourth-generation EGFR tyrosine kinase inhibitors to overcome the C797S triple mutation in non-small cell lung cancer

This Review discusses recent advancements in the development of fourth-generation "Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors (EGFR-TKIs)" targeting resistance mutations, with an emphasis on the C797S mutation in "Non-small Cell Lung Cancer (NSCLC)". While first, second, and third-generation EGFR-TKIs have made significant progress in overcoming EGFR kinase resistance, the emergence of the EGFR-C797S mutation poses a substantial challenge, particularly in the context of resistance to Osimertinib. Fourth-generation TKIs are classified into ATP-competitive, allosteric, and ortho-allosteric inhibitors, with the goal of enhancing specificity for mutant EGFR while minimizing off-target effects on wild-type EGFR to reduce toxicity. This Review provides a detailed analysis of structural modifications and their impact on drug potency and selectivity, with the aim of improving efficacy against resistant NSCLC. Preclinical and early-phase clinical trials of these inhibitors are promising, though further optimization of pharmacokinetic and safety profiles is crucial for future clinical success. This work offers key insights for medicinal chemists in the design and development of fourth-generation EGFR inhibitors to address drug-resistant mutations in NSCLC.

NRP1 overexpression potentially enhances osimertinib resistance in NSCLC via activation of the PI3K/AKT signaling pathway

Resistance to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) is the main cause of mortality in lung cancer. This study aimed to investigate the roles of neuropilin 1 (NRP1) in non-small cell lung cancer (NSCLC). NRP1 expression was assessed in tumor tissues from patients with osimertinib-resistant (OR) NSCLC and osimertinib-responsive NSCLC as well as in patients with paracancerous NSCLC tissues who did not undergo radiotherapy or chemotherapy. In vitro experiments were conducted using five cell lines: BEAS-2B, HCC827, and PC9 cells, and the constructed OR cell lines, HCC827-OR and PC9-OR. HCC827-OR cells showing significant differences in osimertinib IC50 were selected for further study. After investigating the effects of altering NRP1 expression on cell sensitivity to osimertinib, NRP1 expression was inhibited to further investigate changes in cell viability, proliferation, migration, invasion, and apoptosis in OR cells. Additionally, bioinformatics techniques were used to detect targets (Integrin β3) and signaling pathways (PI3K/AKT) downstream of NRP1; subsequent cell experiments verified their interactivity. Finally, an orthotopic mouse tumor model was constructed using HCC827-OR cells treated with a PI3K/AKT signaling pathway activator (740Y-P), allowing exploration of the role played by the PI3K/AKT signaling pathway via NRP1 regulation on NSCLC resistance both in vivo and in vitro. Results showed that NRP1 expression was significantly increased in the cells of patients with NSCLC-OR, and increased NRP1 expression reduced HCC827 cell sensitivity to osimertinib. Both in vitro and in vivo experiments showed that NRP1 deficiency mediated by NRP1 inhibitors inhibited HCC827-OR cell proliferation, migration, and invasion, promoted tumor cell apoptosis, and enhanced osimertinib efficacy. In contrast, 740Y-P partially inhibited the effects of NRP1 inhibitors combined with osimertinib on the PI3K/AKT signaling pathway and on tumor growth in vivo and in vitro. Cellular experimental results showed that NRP1 positively regulates the Integrin β3 expression and activation of the PI3K/AKT signaling pathway. Bioinformatics analysis showed that both NRP1 and Integrin β3 may jointly participate in regulating the PI3K/AKT signaling pathway. In conclusion, our findings suggest that elevated NRP1 expression in NSCLC tumor tissues may promote NSCLC resistance to osimertinib by activating the PI3K/AKT signaling pathway, and integrin β3 potentially being involved in this process. These insights may provide a novel strategy for combination therapy for OR NSCLC.

Novel EGFR inhibitors against resistant L858R/T790M/C797S mutant for intervention of non-small cell lung cancer

To overcome C797S mutation, the latest and most common resistance mechanism in the clinical treatment of third-generation EGFR inhibitor, a novel series of substituted 6-(2-aminopyrimidine)-indole derivatives were designed and synthesized. Through the structure-activity relationship (SAR) study, compound 11eg was identified as a novel and potent EGFR L858R/T790M/C797S inhibitor (IC50 = 0.053 μM) but had a weak effect on EGFRWT (IC50 = 1.05 μM). 11eg significantly inhibited the proliferation of the non-small cell lung cancer (NSCLC) cells harboring EGFRL858R/T790M/C797S with an IC50 of 0.052 μM. 11eg also showed potent inhibitory activity against other NSCLC cell lines harboring main EGFR mutants. Furthermore, 11eg exhibited much superior activity in arresting cell cycle and inducing apoptosis of NSCLC cells with mutant EGFRC797S. It blocked cellular EGFR signaling. Importantly, 11eg markedly suppressed the tumor growth in in vivo xenograft mouse model with good safety. Additionally, 11eg displayed good microsomal stability. These results demonstrated the potential of 11eg with novel scaffold as a promising lead compound targeting EGFRC797S to guide in-depth structural optimization.

The new N2, N4-diphenylpyridine-2,4-diamine deuterated derivatives as EGFR inhibitors to overcome C797S-mediated resistance

A series of new deuterated and non-deuterated N2, N4-diphenylpyridine - 2,4-diamine derivatives were synthesized and evaluated as EGFR C797S-mediated resistance inhibitors. Most of these compounds exhibited potent antiproliferative activity against Baf3-EGFR L858R/T790M/C797S and Baf3-EGFR Del19/T790M/C797S cancel cell lines, with IC50 values in the nanomolar concentration range. Among them, compound 14l represented the most active compound with IC50 values of 8-11 nM. Interestingly, metabolic stability assay with rat liver microsomes indicated that the half-life of the deuterated derivative 14o was significantly increased compared to that of 14l. In xenograft mice models, 14o inhibited tumor growth with excellent inhibitory rate of 75.1 % at the dosage of 40 mg/kg, comparing 73.2 % of the TGI with its non-deuterated compound 14l, at a dosage of 80 mg/kg. Mechanism studies revealed that 14o was a potent EGFR L858R/T790M/C797S and EGFR Del19/T790M/C797S kinase inhibitor, which could downregulate the protein phosphorylation of EGFR and m-TOR signaling pathways, arrest cell cycle at G2/M phase by affecting the expression of CDC25C, and promote cell apoptosis by regulating the expression of cleaved caspase-3. In summary, 14o could serve as a promising deuterated compound for the development of highly efficient anticancer agents.

The anticancer therapeutic potential of pyrimidine-sulfonamide hybrids

Cancer as a devastating malignancy, seriously threatens human life and health, but most chemotherapeutics have long been criticized for unsatisfactory therapeutic efficacy due to drug resistance and severe off-target toxicity. Pyrimidines, including fused pyrimidines, are privileged scaffolds for various biological cancer targets and are the most important class of metalloenzyme carbonic anhydrase inhibitors. Pyrimidine-sulfonamide hybrids can act on different targets in cancer cells simultaneously and possess potent activity against various cancers, revealing that hybridization of pyrimidine with sulfonamide is a promising approach to generate novel effective anticancer candidates. This review aims to summarize the recent progress of pyrimidine-sulfonamide hybrids with anticancer potential, covering papers published from 2020 to present, to facilitate further rational design of more effective candidates.