M4 Receptor Positive Allosteric Modulators for Selective CNS Activation
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Solution Overview
Problem
Current treatments for neurological and psychiatric disorders associated with muscarinic acetylcholine receptor dysfunction, such as schizophrenia, face challenges due to the lack of potent and selective activators of the M4 muscarinic acetylcholine receptor, leading to adverse effects and limited clinical utility.
Innovation Solution
Development of positive allosteric modulators that selectively activate the M4 muscarinic acetylcholine receptor by binding to an allosteric site distinct from the orthosteric binding site, potentially reducing peripheral side effects and improving therapeutic efficacy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If AChE inhibitors are used to increase acetylcholine levels, then therapeutic efficacy is improved, but cholinergic side effects and hepatotoxicity increase
Solution Approach 1:
The invention segments the cholinergic system into specific receptor subtypes (M1, M3, M5 for cognitive functions) versus peripheral subtypes (M2, M3 for side effects). By designing selective M1/M3/M5 agonists that do not activate peripheral M2 receptors, the patent achieves therapeutic efficacy in the CNS while avoiding peripheral cholinergic side effects such as bradycardia, GI distress, and excessive salivation.
Solution Approach 2:
The patent applies local quality by creating compounds with subtype-specific selectivity. The designed agonists have different affinity profiles for various mAChR subtypes, allowing selective activation of central nervous system receptors (M1, M3, M5) involved in cognitive function while sparing peripheral receptors. This subtype-selective approach enables localized therapeutic action in the CNS without systemic cholinergic overstimulation.
2Reliability
If selective M4 agonists are developed, then cognitive function improvement is enhanced, but selectivity and therapeutic utility are limited
Solution Approach 1:
The patent employs a multi-functional approach by designing agonists that can selectively activate multiple cognitive-related mAChR subtypes (M1, M3, and M5) simultaneously. This multi-subtype selectivity provides broader therapeutic coverage for cognitive disorders compared to single-subtype selectivity, while maintaining the ability to avoid peripheral side effects. The compounds exhibit a balanced profile of central selectivity across multiple subtypes involved in cognition.
3Reliability
If mAChR agonists are administered to activate muscarinic receptors, then cholinergic function is augmented, but peripheral side effects increase
Solution Approach 1:
The invention segments the mAChR family into central cognitive subtypes (M1, M3, M5) and peripheral subtypes (M2, M3). By designing agonists with selective affinity for central subtypes and minimal activity at peripheral M2 receptors, the patent achieves CNS cholinergic augmentation while avoiding peripheral side effects. The segmentation strategy creates a therapeutic window that targets cognitive function without systemic cholinergic overstimulation.
Data Source
Figure 1
AI summary
Disclosed herein are pyrido[3',2':4,5]thieno[2,3-d]pyridazin-8-amine and thieno[2,3-c:4,5-d']dipyridazin-8-amine compounds, which may be useful as positive allosteric modulators of the muscarinic acetylcholine receptor M4 (mAChR M4). Also disclosed herein are methods of making the compounds, pharmaceutical compositions comprising the compounds, and methods of treating neurological and psychiatric disorders associated with muscarinic acetylcholine receptor dysfunction using the compounds and compositions.