Fibroblast Activation Protein-Targeted Theranostics: Current Status in Clinical Development

Area of Science:

• Oncology
• Radiochemistry
• Pharmacology

Background:

• Fibroblast activation protein (FAP) is highly expressed in tumor stroma, making it a key target for cancer therapy.
• Radioligand therapy targeting FAP offers a promising approach for cancer treatment and imaging.

Purpose of the Study:

• To review the clinical development of FAP-targeted radioligand therapy.
• To summarize current evidence on the efficacy and limitations of FAP-targeted agents.

Main Methods:

• Review of clinical studies on FAP-targeted radioligand therapy.
• Analysis of early quinoline-based compounds (e.g., FAPI-04, FAPI-46) and structurally modified agents.
• Evaluation of tumor uptake, retention, dosimetry, and toxicity profiles.

Main Results:

• Early FAP-targeted agents showed high tumor uptake but limited therapeutic efficacy due to poor retention.
• Structural modifications (cyclic peptides, dimers, albumin binders) improved tumor retention and dosimetry.
• Clinical studies indicate acceptable toxicity but inconclusive therapeutic outcomes.

Conclusions:

• FAP-targeted radioligand therapy is a developing field with potential.
• Further large-scale clinical trials are needed to establish therapeutic efficacy.
• Ongoing trials aim for regulatory approval and await definitive evidence of treatment benefit.