Discovery and Optimization of Potent and Subtype-Selective Urea-Derived Na_V1.8 Inhibitors

Area of Science:

• Medicinal Chemistry
• Pharmacology
• Neuroscience

Background:

• Voltage-gated sodium channel 1.8 (Na_V1.8) inhibitors offer potential for opioid-free pain management.
• Developing selective Na_V1.8 inhibitors is crucial for treating acute and neuropathic pain.
• Current pain therapeutics often rely on opioids, necessitating non-addictive alternatives.

Purpose of the Study:

• To discover and optimize novel, highly selective Na_V1.8 inhibitors.
• To achieve favorable pharmacokinetic and safety profiles for potential non-opioid pain therapeutics.
• To identify a lead compound with improved potency, clearance, and in vivo exposure.

Main Methods:

• Pharmacophore modeling and virtual screening to identify initial hit compounds.
• Hit-to-lead optimization focusing on potency, clearance, and physicochemical properties.
• Metabolite identification (MetID) studies to understand and optimize metabolic clearance.
• In vitro safety and drug-drug interaction assessments.
• In vivo pharmacokinetic (PK) studies in rats, including tissue distribution.

Main Results:

• Discovery of a novel series of highly selective Na_V1.8 inhibitors.
• Optimization led to compound 24 with improved potency and favorable in vitro safety profile.
• MetID studies identified a metabolic hotspot, enabling clearance optimization.
• Compound 24 demonstrated a long in vivo half-life and high exposure in the dorsal root ganglia (DRG).

Conclusions:

• The novel Na_V1.8 inhibitors represent a promising class of non-opioid pain therapeutics.
• Compound 24 exhibits characteristics suitable for further development as an analgesic.
• These findings support the potential of targeting Na_V1.8 for effective and safe pain relief.