A pH Responsive Transistor-like Nanoprobe for Sensitive Detection of Unknown Primary Cancers of the Head and Neck - A pH Responsive Transistor-like Nanoprobe for Sensitive Detection of Unknown Primary
Cancers of the Head and Neck
Project Summary/Abstract
Approximately 65,000 cases of Head and Neck Squamous Cell Cancer (HNSCC) are
diagnosed each year in the US and arise in the mucosal lining of the upper aerodigestive tract
and spread to local lymph nodes. In some cases, the primary tumor is too small to be detected,
with enlarged nodes being the only manifestation of HNSCC. These unknown primary cancers
(UPCs), often induced by human papilloma virus (HPV), usually arise in the mucosa of Waldeyer's
ring, the lymphatic tonsillar tissues of the pharynx. Finding UPC is significant and impactful
addressing an unmet need with long term oncologic and functional outcomes improved by locating
and removing UPC. However, their detection is impaired by the corrugated, cryptic surface, and
nodularity of lymphatic tissue which decreases the sensitivity of physical examination while the
vascularity and fluorodeoxyglucose (FDG) avidity of the lymphoid tissue obscure small tumors by
computerized tomography (CT) and positron emission tomography (PET).
We have invented a library of ultra pH sensitive (UPS) nanoprobes, covalently conjugated to
indocyanine green (ICG) that respond to acidic tumor microenvironment, with a concomitant sharp
change in their fluorescence state from OFF to ON. One such nanoprobe, ONM-100, has been
developed and studied in a Phase 1 and ongoing FDA approved Phase 2 clinical trial. it has been
shown to be well tolerated with no serious adverse events, compatible with surgical endoscopes,
and able to detect a variety of cancers including HNSCC in real time. Based on these data we
hypothesize that ONM-100 used as an adjunct to SOC panendoscopy can improve detection of
UPC. To test our hypothesis, we will (1) Compare the sensitivity and specificity of activatable
probe ONM-100 for cancer detection to always ON probes for tumors in Waldeyer's ring; (2)
Detect HPV-mediated HNSCC in patients after systemic administration of ONM-100 comparing
fluorescence to true-positive cancers; (3) Detect UPC in patients after systemic administration of
ONM-100. Successful execution of this project will provide precise excision of UPC and avoidance
of intense adjuvant therapy for UPC patients significantly improving care and outcomes for these
patients who suffer greatly from less oncologically effective imprecise overtreatment.