Designing T-cell Engagers: Trade-offs Between Activity and Safety

Area of Science:

• Immunology
• Oncology
• Pharmacology

Background:

• T-cell engagers (TCEs) are potent immunotherapeutics with significant clinical efficacy in various cancers.
• Balancing the antitumor activity and safety profile of TCEs, especially in solid tumors, remains a critical challenge.
• Current molecular design strategies often optimize activity and toxicity independently, limiting therapeutic potential.

Purpose of the Study:

• To systematically analyze principal TCE design strategies, evaluating their strengths, limitations, and interdependencies.
• To provide a holistic framework for navigating the activity-safety trade-off in TCE development.
• To guide the development of next-generation TCEs by integrating mechanistic insights.

Main Methods:

• Categorization of TCE strategies into T-cell interface and tumor cell-directed approaches.
• Review of T-cell focused strategies: anti-CD3 affinity tuning, costimulatory signals, and immunosuppressive pathway blockade.
• Examination of tumor-focused strategies: antigen selection, binding valency, and tumor microenvironment (TME)-responsive activation.

Main Results:

• TCE strategies can be broadly classified based on their targeting interface (T-cell or tumor cell).
• T-cell interface strategies aim for spatiotemporal control of T-cell activation.
• Tumor cell-directed strategies focus on enhancing tumor-selective cytotoxicity through antigen targeting and TME responsiveness.

Conclusions:

• Sophisticated TCE formats allow nuanced functional modulation, but deeper mechanistic understanding is crucial.
• Integrating insights into T-cell activation and TME biology is essential for developing safer and more effective TCEs.
• A systematic comparison of existing strategies offers a framework for optimizing TCE design and improving therapeutic outcomes.