Glecirasib, a Potent and Selective Covalent KRAS G12C Inhibitor Exhibiting Synergism with Cetuximab or SHP2 Inhibitor JAB-3312

Abstract

Glecirasib potently and selectively inhibits KRAS G12C and reduces ERK and AKT phosphorylation in KRAS G12C-mutant cancer cells, further inducing cell-cycle arrest and apoptosis. Glecirasib monotherapy leads to tumor regression in KRAS G12C-mutant animal models and shows synergistic effects with cetuximab or JAB-3312 (sitneprotafib).

Figure 1

Glecirasib is a potent and selective covalent inhibitor targeting GDP-bound KRAS G12C. A, The chemical structure of glecirasib. B, Dose–response curves of compounds in SOS1-mediate nucleotide exchange assays (n = 2). C, The covalent k_inact/K_I second-order rate constant determined by SOS1-mediate nucleotide exchange assay without compound preincubation (n = 2). conc., concentration.

Figure 2

Glecirasib shows high potency and selectivity against cancer cells with RAS G12C mutations in vitro, including KRAS G12C, HRAS G12C, NRAS G12C, KRAS G12C/H95, and KRAS G12C/R68S. A, Inhibition of p-ERK by glecirasib after 2 hours of treatment on multiple cancer cell lines (n = 2). B, 3D cell viability inhibition by glecirasib after 6 days of treatment on multiple cancer cell lines (n = 2). LS513 harbors KRAS p.G12D, Capan-2 harbors KRAS p.G12V, and MKN1 harbors amplification of WT KRAS. C, A profile of NCI-H358 cysteine reactivity with and without glecirasib treatment (1 μmol/L, 4 hours, n = 5). D, Cell viability inhibition by glecirasib (6 days of treatment) on Ba/F3-engineered cell lines carrying KRAS p.G12C, KRAS p.G12C double mutants, NRAS p.G12C, and HRAS p.G12C (n = 3). E, Glecirasib induced cell-cycle arrest in NCI-H358 cells, which were treated with glecirasib for 24 hours (n = 2). Subsequently, cell populations at varying stages of the cell cycle were examined via flow cytometry. F, Time course of caspase 3/7 induction by either glecirasib (1 μmol/L), sotorasib (1 μmol/L), adagrasib (1 μmol/L), or staurosporine (1 μmol/L) in NCI-H358 cells (n = 3). conc., concentration.

Figure 3

Glecirasib inhibited ERK phosphorylation and growth of tumors carrying the KRAS G12C mutation in vivo. A–C, PK/PD studies of a single-dose glecirasib administration in NCI-H358 lung cancer xenograft tumors bearing in the flank of mice. Dose response following a single dose of glecirasib is shown in A. Time-dependent PK/PD properties after a single dose of 30 mg/kg and 100 mg/kg glecirasib are shown in B and C, respectively. After 8 hours, glecirasib concentrations in both plasma and tumor in the 30 mg/kg group, as well as the plasma drug concentration in the 100 mg/kg group, were below the quantification limit (plasma: 1 ng/mL; tumor: 5.5 ng/g). Glecirasib concentrations in plasma and tumor tissue were quantified by LC/MS-MS, whereas p-ERK levels in tumors were measured by HTRF. Three mice per group. D–F,In vivo efficacy studies of glecirasib in CDX models: NCI-H1373 lung cancer (D), NCI-H358 lung cancer (E), and MIA PaCa-2 pancreatic cancer (F). NCI-H1373 and MIA PaCa-2 CDX models: six mice per group; NCI-H358 CDX model: eight mice per group. Glecirasib was administrated once a day orally. G and H, Tumor growth curves (G) and mice body weight curves (H) of the LUN156 lung cancer PDX model after treatment with glecirasib. Six mice per group. All data are represented as the mean ± SEM. conc., concentration; p.o., orally; QD, once a day.

Figure 4

Efficacy of glecirasib in the intracranially implanted NCI-H1373-Luc xenograft model. The curves of bioluminescence in mice head and body weight are shown in A and B. Data are shown as the mean ± SEM. Images of bioluminescence in individual mouse on day 20 are shown in C. Five mice per group. BID, twice a day; p.o., orally.

Figure 5

Cetuximab enhanced the antitumor effect of glecirasib in colorectal cancer models. A, Cell viability (3D) dose–response map and Loewe synergy map of glecirasib in combination with cetuximab on the indicated cancer cell lines (n = 2), with darker blue colors denoting greater cell viability inhibition and deeper red colors demonstrating stronger Loewe synergistic effect. Global Loewe synergy scores are indicated at the top of Loewe synergy maps. Global Loewe synergy score >5 indicates synergistic effect. B and C, Inhibition of p-ERK (B) and p-AKT (C) by either glecirasib, cetuximab, or combinations in SW837 and SW1463 cells (n = 2). The CI for a 50% effect (CI₅₀) was indicated, and CI₅₀ < 0.9 indicates synergistic effect. D and E, Glecirasib and cetuximab combination studies in CR6243 (D) and CR6256 (E) PDX models. Six mice per group. ***, P < 0.001 vs. combination group (day 28). F, Mice were treated with 100 mg/kg sotorasib for 63 days and then randomly grouped and treated either with 100 mg/kg sotorasib, 100 mg/kg glecirasib, or 50 mg/kg cetuximab or glecirasib in combination with cetuximab. Three mice per group. All data are represented as the mean ± SEM. BIW, twice a week; conc., concentration; i.p., intraperitoneally; p.o., orally; QD, once a day.

Figure 6

Glecirasib in combination with the SHP2 inhibitor JAB-3312 synergistically inhibited cancer cell growth. A, Cell viability (2D) dose–response map and Loewe synergy map of glecirasib in combination with JAB-3312 on the indicated cancer cell lines (n = 2), with darker blue colors denoting greater cell viability inhibition and deeper red colors demonstrating stronger Loewe synergistic effect. Global Loewe synergy scores are indicated at the top of Loewe synergy maps. Global Loewe synergy score >5 indicates synergistic effect. B and C, Inhibition of p-ERK (B) and p-AKT (C) by either glecirasib, JAB-3312, or combinations in SW837 and SW1463 (n = 2). The CI for the 50% effect (CI₅₀) was indicated, and CI₅₀ < 0.9 indicates synergistic effect. D, Glecirasib and JAB-3312 combination studies in the NCI-H1373 lung cancer xenograft model. Six mice per group. *, P < 0.05 vs. combination group. All data are shown as the mean ± SEM. conc., concentration; p.o., orally; QD, once a day.