143D, a novel selective KRASG12C inhibitor exhibits potent antitumor activity in preclinical models.

The KRASG12C mutant has emerged as an important therapeutic target in recent years. Covalent inhibitors have shown promising antitumor activity against KRASG12C-mutant cancers in the clinic. In this study, a structure-based and focused chemical library analysis was performed, which led to the identification of 143D as a novel, highly potent and selective KRASG12C inhibitor. The antitumor efficacy of 143D in vitro and in vivo was comparable with that of AMG510 and of MRTX849, two well-characterized KRASG12C inhibitors. At low nanomolar concentrations, 143D showed biochemical and cellular potency for inhibiting the effects of the KRASG12C mutation. 143D selectively inhibited cell proliferation and induced G1-phase cell cycle arrest and apoptosis by downregulating KRASG12C-dependent signal transduction. Compared with MRTX849, 143D exhibited a longer half-life and higher maximum concentration (Cmax) and area under the curve (AUC) values in mouse models, as determined by tissue distribution assays. Additionally, 143D crossed the blood‒brain barrier. Treatment with 143D led to the sustained inhibition of KRAS signaling and tumor regression in KRASG12C-mutant tumors. Moreover, 143D combined with EGFR/MEK/ERK signaling inhibitors showed enhanced antitumor activity both in vitro and in vivo. Taken together, our findings indicate that 143D may be a promising drug candidate with favorable pharmaceutical properties for the treatment of cancers harboring the KRASG12C mutation.

[Study on prevalence and correlation factors of bronchial asthma in Zaozhuang area, Shandong province].

OBJECTIVE: To study the prevalence of asthma and its correlated factors in Zaozhuang area in 2003, to provide a basic consideration for prevention/treatment and control policy. METHODS: 6 points were selected by stratified-clusterd-random sampling with a total of 16,725 persons expected, but only 10,610 subjects investigated. RESULTS: In this survey, 128 asthma cases were identified with a overall prevalence of 1.21%. The prevalence for children was 2.02%, and for adult was 0.90% with the former significantly higher then the latter (chi(2) = 21.39, P < 0.01). Rates for male and female were 1.08%, 1.32% with a ratio of 1:1.22. For 77.97% of children with asthma. The initiative age of asthma was before 7 years old among children while among 36.23% of the adults, it was before 15 years of age. Correlation analysis showed that upper respiratory tract infection (OR = 17.81, 95% CI: 12.25-25.89), cold air exposure (OR = 3.43, 95% CI: 2.41-4.90), stimulation through cooking and by harmful gases (OR = 2.56, 95% CI: 1.80-3.63), allergic materials (OR = 2.74, 95% CI: 1.80-4.17) were main inducing factors. 65.63% of the asthma cases having had history of allergic disease while 25.78% having had family history with the OR of allergic history and family history as 21.69 vs. 73.96. CONCLUSION: The epidemic status of bronchial asthma was serious, with an assumption that asthma cases might have reached the number of 43 thousand in Zaozhuang area.