Design and Synthesis of Clinical Candidate PF-06852231 (CVL-231): A Brain Penetrant, Selective, Positive Allosteric Modulator of the M4 Muscarinic Acetylcholine Receptor.

Selective activation of the M4 muscarinic acetylcholine receptor subtype offers a novel strategy for the treatment of psychosis in multiple neurological disorders. Although the development of traditional muscarinic activators has been stymied due to pan-receptor activation, muscarinic receptor subtype selectivity can be achieved through the utilization of a subtype of a unique allosteric site. A major challenge in capitalizing on this allosteric site to date has been achieving a balance of suitable potency and brain penetration. Herein, we describe the design of a brain penetrant series of M4 selective positive allosteric modulators (PAMs), ultimately culminating in the identification of 21 (PF-06852231, now CVL-231/emraclidine), which is under active clinical development as a novel mechanism and approach for the treatment of schizophrenia.

α5 nAChR modulation of the prefrontal cortex makes attention resilient.

A loss-of-function polymorphism in the α5 nicotinic acetylcholine receptor (nAChR) subunit gene has been linked to both drug abuse and schizophrenia. The α5 nAChR subunit is strategically positioned in the prefrontal cortex (PFC), where a loss-of-function in this subunit may contribute to cognitive disruptions in both disorders. However, the specific contribution of α5 to PFC-dependent cognitive functions has yet to be illustrated. In the present studies, we used RNA interference to knockdown the α5 nAChR subunit in the PFC of adult rats. We provide evidence that through its contribution to cholinergic modulation of cholinergic modulation of neurons in the PFC, the α5 nAChR plays a specific role in the recovery of attention task performance following distraction. Our combined data reveal the potent ability of this subunit to modulate the PFC and cognitive functions controlled by this brain region that are impaired in disease.