Surgery remains the only potentially
curative treatment option
for pancreatic cancer, but resections are made more difficult by infiltrative
disease, proximity of critical vasculature, peritumoral inflammation,
and dense stroma. Surgeons are limited to tactile and visual cues
to differentiate cancerous tissue from normal tissue. Furthermore,
translating preoperative images to the intraoperative setting poses
additional challenges for tumor detection, and can result in undetected
and unresected lesions. Thus, pancreatic ductal adenocarcinoma (PDAC)
has high rates of incomplete resections, and subsequently, disease
recurrence. Fluorescence-guided surgery (FGS) has emerged as a method
to improve intraoperative detection of cancer and ultimately improve
surgical outcomes. Initial clinical trials have demonstrated feasibility
of FGS for PDAC, but there are limited targeted probes under investigation
for this disease, highlighting the need for development of additional
novel biomarkers to reflect the PDAC heterogeneity. MUCIN16 (MUC16)
is a glycoprotein that is overexpressed in 60–80% of PDAC.
In our previous work, we developed a MUC16-targeted murine antibody
near-infrared conjugate, termed AR9.6–IRDye800, that showed
efficacy in detecting pancreatic cancer. To build on the translational
potential of this imaging probe, a humanized variant of the AR9.6
fluorescent conjugate was developed and investigated herein. This
conjugate, termed huAR9.6–IRDye800, showed equivalent binding
properties to its murine counterpart. Using an optimized dye:protein
ratio of 1:1, in vivo studies demonstrated high tumor
to background ratios in MUC16-expressing tumor models, and delineation
of tumors in a patient-derived xenograft model. Safety, biodistribution,
and toxicity studies were conducted. These studies demonstrated that
huAR9.6–IRDye800 was safe, did not yield evidence of histological
toxicity, and was well tolerated in vivo. The results
from this work suggest that AR9.6-IRDye800 is an efficacious and safe
imaging agent for identifying pancreatic cancer intraoperatively through
fluorescence-guided surgery.