RG7090

RG7090 (Basimglurant, RO4917523) is a potent, selective and orally available mGlu5 negative allosteric modulator with a Kd of 1.1 nM.

In Vitro:[3H]-basimglurant saturation analysis on recombinant human mGlu5 reveals monophasic saturation isotherms with Kd of 1.1 nM. In competition binding experiments on human recombinant mGlu5, basimglurant fully displaces [3H]-MPEP with a Ki of 35.6 nM and [3H]-ABP688 with a Ki of 1.4 nM. In HEK293 cells stably expressing human mGlu5, basimglurant inhibits quisqualate induced Ca2+ mobilization with an IC50 of 7.0 nM and [3H]-inositolphosphate accumulation with an IC50 of 5.9 nM. Basimglurant shows similar potencies in radioligand binding and functional assay on human and rodent mGlu5 receptor orthologues[1].

In Vivo:Basimglurant is a potent, selective, and safe mGlu5 inhibitor with good oral bioavailability and long half-life supportive of once-daily administration, good brain penetration, and high in vivo potency. It has antidepressant properties which are corroborated by its functional magnetic imaging (fMRI) profile, as well as anxiolytic-like and antinociceptive features[1]. It is currently in phase II clinical studies for the treatment of depression and fragile X syndrome. In the Vogel conflict drinking test, Basimglurant dose dependently increases the drinking time. The total plasma exposure of efficacious doses of Basimglurant ranges from 5 ng/mL (0.03 mg/kg) to 37 ng/mL (0.3 mg/kg)[2].

References:
[1]. Lindemann L, et al. Pharmacology of basimglurant (RO4917523, RG7090), a unique metabotropic glutamate receptor 5 negative allosteric modulator in clinical development for depression. J Pharmacol Exp Ther. 2015 Apr;353(1):213-33. [2]. Jaeschke G, et al. Metabotropic glutamate receptor 5 negative allosteric modulators: discovery of 2-chloro-4-[1-(4-fluorophenyl)-2,5-dimethyl-1H-imidazol-4-ylethynyl]pyridine (basimglurant, RO4917523), a promising novel medicine for psychiatric diseases.

Pharmacology of basimglurant (RO4917523, RG7090), a unique metabotropic glutamate receptor 5 negative allosteric modulator in clinical development for depression.[Pubmed:25665805]

J Pharmacol Exp Ther. 2015 Apr;353(1):213-33.

Major depressive disorder (MDD) is a serious public health burden and a leading cause of disability. Its pharmacotherapy is currently limited to modulators of monoamine neurotransmitters and second-generation antipsychotics. Recently, glutamatergic approaches for the treatment of MDD have increasingly received attention, and preclinical research suggests that metabotropic glutamate receptor 5 (mGlu5) inhibitors have antidepressant-like properties. Basimglurant (2-chloro-4-[1-(4-fluoro-phenyl)-2,5-dimethyl-1H-imidazol-4-ylethynyl]-pyridine) is a novel mGlu5 negative allosteric modulator currently in phase 2 clinical development for MDD and fragile X syndrome. Here, the comprehensive preclinical pharmacological profile of basimglurant is presented with a focus on its therapeutic potential for MDD and drug-like properties. Basimglurant is a potent, selective, and safe mGlu5 inhibitor with good oral bioavailability and long half-life supportive of once-daily administration, good brain penetration, and high in vivo potency. It has antidepressant properties that are corroborated by its functional magnetic imaging profile as well as anxiolytic-like and antinociceptive features. In electroencephalography recordings, basimglurant shows wake-promoting effects followed by increased delta power during subsequent non-rapid eye movement sleep. In microdialysis studies, basimglurant had no effect on monoamine transmitter levels in the frontal cortex or nucleus accumbens except for a moderate increase of accumbal dopamine, which is in line with its lack of pharmacological activity on monoamine reuptake transporters. These data taken together, basimglurant has favorable drug-like properties, a differentiated molecular mechanism of action, and antidepressant-like features that suggest the possibility of also addressing important comorbidities of MDD including anxiety and pain as well as daytime sleepiness and apathy or lethargy.