Click Chemistry for Target Engagement Studies.

Area of Science:

• Chemical biology
• Proteomics
• Pharmacology

Background:

• Targeted covalent small molecule inhibitors are increasingly used in clinical development.
• Understanding on- and off-target engagement is crucial for efficacy and safety assessment.
• Existing methods may not fully capture the complex interactions of covalent inhibitors.

Purpose of the Study:

• To optimize a click chemistry-based chemoproteomic approach for studying covalent molecule target engagement.
• To characterize the mechanistic profile of the Bruton's tyrosine kinase (BTK) inhibitor ibrutinib.
• To provide a robust method for evaluating target binding and inhibition of covalent drugs.

Main Methods:

• Development and optimization of a click chemistry-enabled chemoproteomic workflow.
• Application of the method to study ibrutinib, a BTK inhibitor.
• Quantification of on- and off-target engagement in cell-based systems.

Main Results:

• Successfully optimized a click chemistry chemoproteomic approach for covalent inhibitor studies.
• Demonstrated the utility of the method in characterizing ibrutinib's target engagement profile.
• Provided quantitative data on on- and off-target interactions.

Conclusions:

• The optimized click chemistry chemoproteomic method is effective for studying covalent small molecule inhibitors.
• This approach enhances the understanding of drug mechanisms, target binding, and potential side effects.
• The validated method offers a valuable tool for drug discovery and development.