Best practices for optimization and validation of flow cytometry-based receptor occupancy assays

Area of Science:

• Pharmacology
• Biotechnology
• Immunology

Background:

• Assessing drug-target engagement is critical for therapeutic compound development.
• Flow cytometry is a key technology for monitoring cell-associated targets via receptor occupancy assays (ROA).
• Challenges exist in ROA, especially with receptor modulation, low target expression, and bispecific therapeutics.

Purpose of the Study:

• To discuss the inherent challenges in designing, developing, and implementing robust receptor occupancy assays (ROA).
• To propose best practices for optimizing and validating ROA, particularly for complex therapeutic molecules.
• To enhance the reliability of drug engagement studies for cell surface targets.

Main Methods:

• Utilizing flow cytometry for receptor occupancy assays (ROA).
• Analyzing techniques for identifying specific cell subsets within heterogeneous populations.
• Evaluating methods for detecting non-abundant cellular antigens.

Main Results:

• Identified significant challenges in ROA design and execution.
• Highlighted difficulties associated with receptor modulation and low-abundance targets.
• Addressed increased complexity when dealing with bispecific therapeutic molecules.

Conclusions:

• Robust ROA are essential for validating drug-target engagement in therapeutic development.
• Addressing specific challenges can improve the accuracy and reliability of ROA.
• Best practices are proposed to guide the optimization and validation of ROA for diverse applications.