Cancer cell metabolism leads to a uniquely acidic microenvironment in solid tumors, but exploiting the labile extracellular pH differences between cancer and normal tissues for clinical use has been challenging. Here we describe the clinical translation of ONM-100, a nanoparticle-based fluorescent imaging agent. This is comprised of an ultra-pH sensitive amphiphilic polymer, conjugated with indocyanine green, which rapidly and irreversibly dissociates to fluoresce in the acidic extracellular tumor microenvironment due to the mechanism of nanoscale macromolecular cooperativity. Primary outcomes were safety, pharmacokinetics and imaging feasilibity of ONM-100. Secondary outcomes were to determine a range of safe doses of ONM-100 for intra-operative imaging using commonly used fluorescence camera systems. In this study (Netherlands National Trial Register #7085), we report that ONM-100 was well tolerated, and four solid tumor types could be visualized both in- and ex vivo in thirty subjects. ONM-100 enables detection of tumor-positive resection margins in 9/9 subjects and four additional otherwise missed occult lesions. Consequently, this pH-activatable optical imaging agent may be clinically beneficial in differentiating previously unexploitable narrow physiologic differences.

Tumor-positive resection margins are present in up to 23% of head and neck cancer (HNC) surgeries, as intraoperative techniques for real-time evaluation of the resection margins are lacking. In this study, we investigated the safety and potential clinical value of fluorescence-guided imaging (FGI) for resection margin evaluation in HNC patients. We determined the optimal cetuximab-800CW dose by quantification of intrinsic fluorescence values using multi-diameter single-fiber reflectance, single-fiber fluorescence (MDSFR/SFF) spectroscopy.

A direct comparison of severe acute respiratory syndrome coronavirus 2 positive patients with a severe acute respiratory syndrome coronavirus 2 negative control group undergoing an operative intervention during the current pandemic is lacking, and a reliable estimate of the assumed difference in morbidity and mortality between both patient categories remains unknown. We included all consecutive patients with a confirmed pre- or postoperative severe acute respiratory syndrome coronavirus 2 positive status (operated in 27 hospitals) and negative control patients (operated in 4 hospitals) undergoing emergency or elective operations. A propensity score-matched comparison of clinical outcomes was performed between severe acute respiratory syndrome coronavirus 2 positive and negative tested patients (control group). Primary outcome was overall 30-day mortality rate between both groups. Main secondary outcomes were overall, pulmonary, and thromboembolic complications. In total, 161 severe acute respiratory syndrome coronavirus 2 positive and 342 control severe acute respiratory syndrome coronavirus 2 negative patients were included in this study. The 30-day overall postoperative mortality rate was greater in the severe acute respiratory syndrome coronavirus 2 positive cohort compared with the negative control group (16% vs 4% respectively; P = .007). After propensity score matching, the severe acute respiratory syndrome coronavirus 2 positive group consisted of 123 patients (median 70 years of age [interquartile range 59–77] and 55% male) were compared with 196 patients in the matched control group (median 69 years (interquartile range 58–75] and 53% male). The 30-day mortality rate and risk were greater in the severe acute respiratory syndrome coronavirus 2 positive group compared with the matched control group (12% vs 4%; P = .009 and odds ratio 3.4 [95% confidence interval 1.5–8.5]; P = .005, respectively). Overall, pulmonary and thromboembolic complications occurred more often in severe acute respiratory syndrome coronavirus 2 positive patients (P < .01). Patients diagnosed with perioperative severe acute respiratory syndrome coronavirus 2 have an increased risk of 30-day mortality, pulmonary complications, and thromboembolic events. These findings serve as an evidence-based argument to postpone elective surgery and selected emergency cases.

Rationale: Resection of soft tissue sarcomas (STS) is accompanied by a high rate of tumor-positive surgical margins (14-34%), which potentially leads to decreased disease-free survival. Vascular Endothelial Growth Factor-A (VEGF-A) is overexpressed in malignant tumors, including STS, and can be targeted with bevacizumab-800CW during fluorescence-guided surgery for real-time tumor detection. In this phase 1 clinical trial, we determined the feasibility, safety and optimal dose of bevacizumab-800CW for fluorescence-guided surgery (FGS) in STS for in- and ex vivo tumor detection. Methods: Patients with a histopathologically diagnosis of STS were included. In the dose-escalation phase, patients received bevacizumab-800CW intravenously 3 days prior to surgery (10, 25 and 50 mg, n = 8). In the subsequent dose-expansion phase, 7 additional patients received bevacizumab-800CW at the optimal dose. Fluorescence images in- and ex vivo were obtained during all stages of standard of care. The optimal dose was determined by calculating in- and ex vivo Tumor-to-Background ratios (TBR) and correlating these results with histopathology. Results: Fifteen patients with STS completed this study. All tumors could be visualized during in- and ex vivo imaging. The optimal bevacizumab-800CW dose proved to be 10 mg with a median in vivo TBR of 2.0 (±0.58) and an ex vivo TBR of 2.67 (±1.6). All seven tumor-positive margins could be observed real-time after surgical resection. Conclusion: FGS using 10 mg bevacizumab-800CW is feasible and safe for intra-operative imaging of STS, potentially allowing tumor detection and margin assessment during surgery. An additional follow-up phase II study is needed to confirm the diagnostic accuracy.

Purpose: Intra-operative management of the surgical margin in patients diagnosed with head and neck squamous cell carcinoma (HNSCC) remains challenging as surgeons still have to rely on visual and tactile information. Fluorescence-guided surgery using tumor-specific imaging agents can assist in clinical decision-making. However, a standardized imaging methodology is lacking. In this study, we determined whether a standardized, specimen-driven, fluorescence imaging framework using ONM-100 could assist in clinical decision-making during surgery. Procedures: Thirteen patients with histologically proven HNSCC were included in this clinical study and received ONM-100 24 ± 8 h before surgery. Fluorescence images of the excised surgical specimen and of the surgical cavity were analyzed. A fluorescent lesion with a tumor-to-background ratio (TBR) > 1.5 was considered fluorescence-positive and correlated to standard of care (SOC) histopathology. Results: All six tumor-positive surgical margins were detected immediately after excision using fluorescence-guided intra-operative imaging. Postoperative analysis showed a median TBR (±IQR) of the fluorescent lesions on the resection margin of 3.36 ± 1.62. Three fluorescence-positive lesions in the surgical cavity were biopsied and showed occult carcinoma and severe dysplasia, and a false-positive fluorescence lesion. Conclusion: Our specimen-driven fluorescence framework using a novel, pH-activatable, fluorescent imaging agent could assist in reliable and real-time adequate clinical decision-making showing that a fluorescent lesion on the surgical specimen with a TBR of 1.5 is correlated to a tumor-positive resection margin. The binary mechanism of ONM-100 allows for a sharp tumor delineation in all patients, giving the surgeon a clinical tool for real-time margin assessment, with a high sensitivity.

Vulnerable atherosclerotic carotid plaques are prone to rupture, resulting in ischemic strokes. In contrast to radiological imaging techniques, molecular imaging techniques have the potential to assess plaque vulnerability by visualizing diseases-specific biomarkers. A risk factor for rupture is intra-plaque neovascularization, which is characterized by overexpression of vascular endothelial growth factor-A (VEGF-A). Here, we study if administration of bevacizumab-800CW, a near-infrared tracer targeting VEGF-A, is safe and if molecular assessment of atherosclerotic carotid plaques in vivo is possible using multispectral optoacoustic tomography (MSOT). Healthy volunteers and patients with symptomatic carotid artery stenosis scheduled for carotid artery endarterectomy were imaged with MSOT. Secondly, patients were imaged two days after intravenous administration of 4.5 bevacizumab-800CW. Ex vivo fluorescence molecular imaging of the surgically removed plaque specimen was performed and correlated with histopathology. In this first-in-human MSOT and fluorescence molecular imaging study, we show that administration of 4.5 mg bevacizumab-800CW appeared to be safe in five patients and accumulated in the carotid atherosclerotic plaque. Although we could visualize the carotid bifurcation area in all subjects using MSOT, bevacizumab-800CW-resolved signal could not be detected with MSOT in the patients. Future studies should evaluate tracer safety, higher doses of bevacizumab-800CW or develop dedicated contrast agents for carotid atherosclerotic plaque assessment using MSOT.