Targeted Fluorescence Imaging of Bevacizumab-800CW in Patients with Neovascular Age-Related Macular Degeneration

The purpose of this study was to determine the safety and feasibility of fluorescence molecular imaging using a commercially available system and intravenous injection of fluorescently labeled bevacizumab (bevacizumab-800CW) to visualize bevacizumab distribution in patients with neovascular age-related macular degeneration (nAMD)s. Methods: Twelve patients with active nAMD aged 60 y or older, who were either on anti-vascular endothelial growth factor (VEGF) therapy or were anti-VEGF therapy naïve, received an intravenous injection of 4.5 mg (n = 3) or 15 mg (n = 9) of bevacizumab-800CW. This clinical trial was divided into 2 parts. An interim analysis was performed after the inclusion of 3 patients per dose group (study part 1) to determine the more optimal dose. Then 6 additional patients were included with the optimal dose in study part 2. All patients underwent standard clinical imaging, including fundus photography, optical coherence tomography, optical coherence tomography angiography, and fluorescein angiography. Fluorescence imaging was performed 1 min, 60 min, and 3-4 d after bevacizumab-800CW injection. Results: Bevacizumab-800CW injections were safe and well tolerated. One minute after injection, only the 15-mg group demonstrated a significantly higher contrast-to-noise ratio (median, 6.32) in vessels compared with baseline (median, -4.44; P = 0.0342). This, combined with the clear visual uptake after 3-4 d, supported 15 mg as the preferred dose. Contrast-to-noise ratio values inside the macula of patients receiving 15 mg of bevacizumab-800CW (n = 8) were significantly higher after 3-4 d (median, 4.45) compared with baseline (median, 0.19; P = 0.0078). Conclusion: Targeted fluorescent tracers such as bevacizumab-800CW can visualize VEGF expression, providing important insights into nAMD, and can pave the way toward personalized treatments and targeted drug development.