Single-Domain Antibodies and the Promise of Modular Targeting in Cancer Imaging and Treatment

Area of Science:

• Biotechnology
• Immunology
• Oncology

Background:

• Monoclonal antibodies and fragments are crucial in cancer treatment, inhibiting proliferation and mediating cell death.
• Recombinant antibody fragments, especially single-domain antibodies (sdAbs) from VHH and VNAR genes, offer advantages in drug development due to their small size and retained binding capacity.
• sdAbs are engineered to target various cellular components and pathways, including enzymes, soluble factors, cell surface receptors, and cytoplasmic targets.

Purpose of the Study:

• To review recent data on the clinical application of engineered, recombinant sdAbs in targeting and inhibiting solid tumor growth.
• To evaluate the suitability of sdAbs as epitope recognition modules for constructing monomeric, dimeric, and multimeric ligands for cancer therapy.
• To discuss the clinical efficacy, safety requirements, and potential challenges associated with sdAb drug development.

Main Methods:

• Compilation of recent data on engineered, recombinant sdAb applications in preclinical and clinical settings.
• Analysis of sdAb properties such as size, affinity, specificity, and development profiles.
• Review of case studies and clinical trial outcomes, including adverse events and their implications.

Main Results:

• Engineered sdAbs have been successfully developed as ligands to target, tag, and inhibit solid tumor growth in vivo.
• The size, affinity, specificity, and development profile of sdAb drugs align with desirable clinical efficacy and safety standards.
• A phase I clinical trial was halted due to hepatotoxicity observed in patients with pre-existing anti-drug antibodies, highlighting the need for pre-screening.

Conclusions:

• Engineered sdAbs represent a promising class of therapeutics for solid tumors, offering targeted delivery and effector functions.
• The clinical success of sdAbs depends on careful drug design and thorough pre-screening for potential immune and poly-specific reactivities to ensure safety and efficacy.
• Further research and development are needed to optimize sdAb-based therapies and mitigate risks associated with immunogenicity and off-target effects.