Efficacy of depatuxizumab mafodotin (ABT-414) in preclinical models of head and neck cancer.

Epidermal growth factor receptor (EGFR) is highly expressed in 80-90% of head and neck squamous cell carcinomas (HNSCCs), making it an ideal target for antibody-drug conjugates. Depatuxizumab mafodotin (ABT-414), is an EGFR-targeting ADC comprised of the monoclonal antibody ABT-806 conjugated to monomethyl auristatin F, a tubulin polymerization inhibitor. This study assessed the in vivo efficacy of ABT-414 in HNSCC. The effects of ABT-414 on HNSCCs were determined using in vitro cytotoxicity assays and in vivo flank xenograft mouse models. The distribution of ABT-414 was assessed ex vivo via optical imaging methods using a conjugate of ABT-414 to the near-infrared agent IRDye800. In vitro treatment of high EGFR-expressing human HNSCC cell lines (UMSCC47 and FaDu) with ABT-414 (0-3.38 nM) resulted in dose-dependent cell death (IC50 values of 0.213 nM and 0.167 nM, respectively). ABT-414 treatment of the FaDu mouse xenografts displayed antitumor activity (P = 0.023) without a change in body mass (P = 0.1335), whereas treatment of UMSCC47 did not generate a significant response (P = 0.1761). Fluorescence imaging revealed ABT-414-IRDye800 accumulation in the tumors of both FaDu and UMSCC47 cell lines, with a signal-to-background ratio of >10. ABT-414 treatment yielded antitumor activity in FaDu tumors, but not in UMSCC47, highlighting the potential for ABT-414 efficacy in high EGFR-expressing tumors. Although ABT-414-IRDye800 localized tumors in both cell lines, the differing antitumor responses highlight the need for further investigation into the role of the tumor microenvironment in drug delivery.

Identification of Optimal Tissue-Marking Dye Color for Pathological Evaluation in Fluorescence Imaging Using IRDye800CW.

PURPOSE: Fluorescence-guided surgery using a tumor-specific antibody-dye conjugate is useful in various cancer types. Fluorescence imaging is a valuable tool both intraoperatively and postoperatively for ex vivo imaging. The color of inks used for tumor specimens during ex vivo specimen processing in pathology is an important consideration for fluorescence imaging since the absorption/emission of the dyes may interfere with the fluorescent dye. This study assesses suitable ink colors for use specifically with IRDye800CW fluorescence imaging. PROCEDURES: Eight tissue-marking inks or dyes (TMDs) commonly used for pathological evaluation were assessed. Agarose tissue-mimicking phantoms containing Panitumumab-IRDye800CW were used as an initial model. Mean fluorescence intensity was measured at 800 nm using both Pearl Trilogy as a closed-field fluorescence imaging system and pde-neo II as an open-field fluorescence imaging system before and after TMD application. An in vivo mouse xenograft model using the human head and neck squamous cell carcinoma FaDu cell line was then used in conjunction with TMDs. RESULTS: The retained IRDye800CW fluorescence on Pearl Trilogy was as follows: yellow at 91.0 ± 4.5%, red at 90.6 ± 2.7%, orange at 88.2 ± 2.2%, violet at 56.6 ± 1.1%, lime at 40.9 ± 1.8%, green at 19.3 ± 2.8%, black at 13.3 ± 0.6%, and blue at 8.1 ± 0.2%. The retained IRDye800CW fluorescence on pde-neo II was as follows: yellow at 86.5 ± 6.4%, red at 77.0 ± 6.2%, orange at 76.9 ± 2.8%, lime at 72.5 ± 9.5%, violet at 59.7 ± 0.4%, green at 30.1 ± 6.9%, black at 17.0 ± 2.7%, and blue at 6.7 ± 1.7%. The retained IRDye800CW fluorescence in yellow and blue TMDs was 42.1 ± 14.9% and 0.2 ± 0.2%, respectively in the mouse experiment (p = 0.039). CONCLUSION: Yellow, red, and orange TMDs should be used, and blue and black TMDs should be avoided for evaluating tumor specimens through fluorescence imaging using IRDye800CW.

Current and Future Applications of Fluorescence-Guided Surgery in Head and Neck Cancer.

Despite improvements in medical management of head and neck cancers, positive surgical margin rates have remained relatively unchanged in the past 30 years, emphasizing a need for improved intraoperative imaging and tumor visualization. This review provides a detailed summary on preoperative anatomic imaging techniques, nonspecific fluorescence imaging modalities, the recent emergence of tumor-targeting fluorophores for intraoperative imaging, and the future of fluorescence-guided surgery in head and neck cancer.

A real-time GPU-accelerated parallelized image processor for large-scale multiplexed fluorescence microscopy data.

Highly multiplexed, single-cell imaging has revolutionized our understanding of spatial cellular interactions associated with health and disease. With ever-increasing numbers of antigens, region sizes, and sample sizes, multiplexed fluorescence imaging experiments routinely produce terabytes of data. Fast and accurate processing of these large-scale, high-dimensional imaging data is essential to ensure reliable segmentation and identification of cell types and for characterization of cellular neighborhoods and inference of mechanistic insights. Here, we describe RAPID, a Real-time, GPU-Accelerated Parallelized Image processing software for large-scale multiplexed fluorescence microscopy Data. RAPID deconvolves large-scale, high-dimensional fluorescence imaging data, stitches and registers images with axial and lateral drift correction, and minimizes tissue autofluorescence such as that introduced by erythrocytes. Incorporation of an open source CUDA-driven, GPU-assisted deconvolution produced results similar to fee-based commercial software. RAPID reduces data processing time and artifacts and improves image contrast and signal-to-noise compared to our previous image processing pipeline, thus providing a useful tool for accurate and robust analysis of large-scale, multiplexed, fluorescence imaging data.