c-Met inhibitor JNJ38877605 has proven curative as an antitumor agent, while its clinical study was terminated due to renal toxicity. It was reported that the renal toxicity was caused by the poor solubility of its aldehyde oxidase (AO) metabolites. Therefore, blocking AO oxidation of JNJ38877605 might diminish the toxic metabolites and overcome the renal toxicity. Compound 3, the AO metabolic site deuterated JNJ38877605, was then synthesized as the target molecule. In vitro monkey liver S9 fraction incubation of 3 manifested that the renal toxic metabolite M2-2 was significantly reduced, which connoted that this deuteration has partly blocked AO oxidation. After po. nasal gavage to cynomolgus monkeys, compound 3 revealed decreased AO metabolites M2-2 and M3-2 in the plasma as well as 1.88-fold AUC and 1.56-fold C max compared with JNJ38877605, indicating that deuterium replacement significantly blocked AO metabolism in vivo. Besides, metabolic profiles of 3 were investigated by analysis of the plasma and the urine of the po. administrated cynomolgus monkeys. Moreover, after oral administration to the EBC-1 tumor-bearing nude mice, compound 3 exhibited a better antitumor efficacy than JNJ38877605. In conclusion, deuteration on the AO metabolic site of JNJ38877605 improved its AO metabolism, oral exposure, as well as in vivo antitumor efficacy.

Stimulator of interferon gene (STING) is increasingly exploited for the potential in cancer immunotherapy, yet its mechanism of activation remains not fully understood. Herein, we designed a novel STING agonist, designated as HB3089 that exhibits robust and durable anti-tumor activity in tumor models across various cancer types. Cryo-EM analysis reveals that HB3089-bound human STING has structural changes similar to that of the STING mutant V147L, a constitutively activated mutant identified in patients with STING-associated vasculopathy with onset in infancy (SAVI). Both structures highlight the conformational changes of the transmembrane domain (TMD), but without the 180°-rotation of the ligand binding domain (LBD) previously shown to be required for STING activation. Further structure-based functional analysis confirmed a new STING activation mode shared by the agonist and the SAVI-related mutation, in which the connector linking the LBD and the TMD senses the activation signal and controls the conformational changes of the LBD and the TMD for STING activation. Together, our findings lead to a new working model for STING activation and open a new avenue for the rationale design of STING-targeted therapies either for cancer or autoimmune disorders.

Both c-Met and VEGFR-2 are important targets for cancer therapies. Here we report a series of potent dual c-Met and VEGFR-2 inhibitors bearing an anilinopyrimidine scaffold. Two novel synthetic protocols were employed for rapid analoguing of the designed molecules for structure-activity relationship (SAR) exploration. Some analogues displayed nanomolar potency against c-Met and VEGFR-2 at enzymatic level. Privileged compounds 3a, 3b, 3g, 3h, and 18a exhibited potent antiproliferative effect against c-Met addictive cell lines with IC50 values ranged from 0.33 to 1.7 μM. In addition, a cocrystal structure of c-Met in complex with 3h has been determined, which reveals the binding mode of c-Met to its inhibitor and helps to interpret the SAR of the analogues.