Identification of the optimal therapeutic antibody for fluorescent imaging of cutaneous squamous cell carcinoma

Area of Science:

• Oncology
• Medical Imaging
• Immunotherapy

Background:

• Intraoperative fluorescence imaging enhances tumor visualization and resection.
• Accurate pathological assessment postoperatively is crucial.
• Identifying optimal imaging agents is key for clinical translation.

Purpose of the Study:

• To determine the best FDA-approved therapeutic monoclonal antibody for optical imaging of cutaneous squamous cell carcinoma (cSCC).
• To evaluate the efficacy of fluorescently labeled antibodies in detecting cSCC tumors.
• To assess the potential clinical utility of these agents for intraoperative tumor detection.

Main Methods:

• Covalently linked a near-infrared (NIR) fluorescent probe (IRDye800) to bevacizumab, panitumumab, and tocilizumab.
• Injected labeled antibodies systemically into immunodeficient mice bearing cSCC models (SCC13 cell lines or human tumor explants).
• Imaged and resected tumors using FDA-approved SPY and Pearl Impulse imaging systems.

Main Results:

• All fluorescently labeled antibodies successfully differentiated tumor from normal tissue in SCC13 xenografts, achieving tumor-to-background ratios (TBRs) of 1.2-2 (SPY) and 1.6-3.6 (Pearl).
• No significant difference in imaging performance was observed between the tested antibodies in SCC13 models (p > 0.89).
• Panitumumab-IRDye800 demonstrated the highest tumor detection in human tumor explants with TBRs of 3.0 (SPY) and 4.0 (Pearl).

Conclusions:

• FDA-approved therapeutic monoclonal antibodies, when conjugated with NIR probes, can serve as effective agents for intraoperative optical imaging of cSCC.
• These findings support the clinical potential of antibody-based fluorescence imaging for enhancing cSCC detection and resection.
• Further investigation into specific antibody-tumor interactions may optimize imaging sensitivity and specificity.