ARS-1620

Our results revealed that the atropisomeric core of ARS-1620 is not indispensable for KRASG12C inhibition, the basic side chain has little effect on either binding step, and warheads affect the covalent reactivity but not the noncovalent binding. This type of analysis helps identify structural determinants of efficient covalent inhibition and may find use in the design of covalent agents.

Especially, K45 exhibited strong antiproliferative potency on NCI-H23 and NCI-H358 cancer cells harboring KRAS-G12C with the IC50 values of 0.77 μM and 1.50 μM, which was 15 and 11 times as potent as positive drug ARS1620, respectively...Docking studies displayed that the 3-naphthylmethoxy moiety of K45 extended into the cryptic pocket formed by the residues Gln99 and Val9, which enhanced the interaction with the KRAS-G12C protein. These results indicated that K45 was a potent KRAS-G12C inhibitor worthy of further study.

Above genes were relevant to tumor cell resistance to targeted therapy. This study provides important insights into the molecular mechanisms underlying tumor cell resistance to KRAS inhibitor treatment.

Gene expression studies revealed that MAPK expression is strongly correlated with decreased cellular proliferation following treatment with KRAS inhibitor BAY-293, but not treatment with ARS-1620 or osimertinib. These results indicate that our precision medicine pipeline may be used to identify compounds capable of synergizing with inhibitors of KRAS G12C, and to assess their likelihood of becoming drugs by understanding their behavior at the proteomic/interactomic scales.

A series of novel quinazoline analogs were designed and synthesized based on ARS-1620 and LLK-10 (a KRAS inhibitor reported by us recently) as KRAS G12C inhibitors with a 5-nitrofuran-2-carboxylic acid warhead...Lastly, KS-19 possessed a benign toxicity profile without causing bone marrow suppression and any obvious morphological abnormalities in major organs of mice. Collectively, these results suggest that KS-19 represents a novel inhibitor of KRAS G12C worthy of further investigation as a potential anticancer agent.

In H358 lung carcinoma cells, IDO1 expression induced by IFN-γ was at least in part dependent on ERK activation, and treatment with ARS-1620, a covalent KRas inhibitor, suppressed IDO1 expression induced by IFN-γαμμα in a concentration-dependent manner...In addition, KRas downregulation by specific siRNAs decreased IFN-γ-induced IDO1 expression in A549 lung cancer cells. Taken together, our study strongly suggests that Ras/ERK signaling pathway plays an important role in promoting IDO1 expression induced by IFN-γ.

Lastly, K20 exhibited benign toxicity profiles without causing bone marrow suppression and any other apparent toxicity to major organs of mice. Collectively, these results indicate that K20 is a KRas G12C inhibitor deserving further investigation.

In H358 lung carcinoma cells, IDO1 expression induced by IFN-γ was at least in part dependent on ERK activation, and treatment with ARS-1620, a covalent KRasG12C inhibitor, suppressed IDO1 expression induced by IFN-γ in a concentration-dependent manner...In addition, KRas downregulation by specific siRNAs decreased IFN-γ-induced IDO1 expression in A549 lung cancer cells. Taken together, our study strongly suggests that Ras/ERK signaling pathway plays an important role in promoting IDO1 expression induced by IFN-γ.

In this study, we showed that LY3009120, a pan-RAF inhibitor, can unexpectedly cause paradoxical ERK activation in KRAS-dependent lung cancer cell lines, when KRAS is inhibited by ARS1620, a KRAS inhibitor. We further showed that the MRAS/SHOC2 complex is required for this process. This study highlights the complexity of the allosteric RAF regulation by RAF inhibitors, and the importance of other RAS-related proteins in this process.

These data provide a novel approach using NIR-labeled human serum albumin to identify and monitor RAS-driven tumors as well as evaluate the on-target efficacy in vivo of inhibitors, such as ARS-1620.

A series of novel quinazoline analogs with a variety of cysteine-targeting warheads (electrophiles) were designed and synthesized based on ARS-1620 as covalent KRAS G12C inhibitors...The high binding affinity of LLK10 was further confirmed by the isothermal titration calorimetry (ITC) assay in which LLK10 exhibited a K of 115 nM for binding to KRAS G12C. These results suggest that the novel covalent inhibitors of KRAS G12C with different warheads deserve further investigation as potential anticancer agents.

Our phosphoproteomic study identified cell-type adaptive responses to KRASG12C inhibitors. Markers and targets associated with ERBB2/3 signaling in epithelial subtype and FGFR1/AXL signaling in mesenchymal subtype should be considered in patient enrichment schemes with KRASG12C inhibitors.

Adding mTOR and IGF1R inhibitors to ARS-1620 greatly improves its effectiveness on KRAS-G12C mutant lung cancer cells in vitro and in mouse models. This provides a rationale for the design of combination treatments to enhance the impact of the KRAS-G12C inhibitors, which are now entering clinical trials.

ARS-1620 (G12C-specific inhibitor) disrupts the KRAS-AGO2 interaction, suggesting that the interaction is targetable. Altogether, our study supports a biphasic model of pancreatic cancer development: an AGO2-independent early phase of PanIN formation reliant on EGFR-RAS signaling, and an AGO2-dependent phase wherein the mutant KRAS-AGO2 interaction is critical for PDAC progression.

Our findings suggest that signaling adaptation can in some instances limit the efficacy of ARS1620 but combination with PI3K inhibitors can overcome this resistance.