Fluorescence Molecular Endoscopy of locally advanced esophageal carcinoma using bevacizumab-800CW to evaluate dose response after neoadjuvant chemoradiotherapy: a single-center feasibility study.

For locally advanced esophageal cancer (EC), neoadjuvant chemoradiotherapy
(nCRT) for 5 weeks followed by esophagectomy and lymphadenectomy, if necessary,
is standard of care. It is reported that the pathological complete response
(pCR) rate after nCRT ranges from 16% to 43%, with a median of 26.5% [1].
According to current clinical guidelines, patients who achieved pCR still go
for surgery even though those patients who achieved pCR may not benefit from
surgery. Besides, about 50% of EC patients may have post-operative
complications including pneumonia, anastomotic leakage, recurrent laryngeal
nerve paralysis, which lead to low health-related quality of life (HQoL) [2,3].
The golden standard to test the pathological response is by pathological
assessment of the surgical specimen and thus after surgery. Theoretically, if
pCR after nCRT can be predicted accurately before surgery by advanced imaging
techniques, patients could have a wait-and-see. The wait-and-see procedure
includes regular follow-up and salvage surgery if recurrence is present.
Therefore, molecular fluorescence endoscopy (FME) using near-infrared
fluorescence (NIRF) tracer bevacizumab-800CW targeting vascular endothelial
growth factor combined with high-definition white light (HD-WL) endoscopy is
expected to be a promising technique to monitor pCR and fill the gap.

The primary objective of this study is to determine the safety and feasibility
of fluorescence molecular endoscopy using the fluorescent tracer
bevacizumab-800CW for identification of pathological complete response after
neoadjuvant chemoradiotherapy in patients with a locally advanced esophageal
carcinoma.

Secondary Objectives
• To quantify fluorescence intensity in vivo and ex vivo with multi-diameter
single-fiber reflectance, single-fiber fluorescence (MDSFR-SFF) spectroscopy;
• To correlate and validate both the in vivo and ex vivo measured fluorescence
signals with histopathological analysis and IHC staining;
• To validate the (sub)-cellular location of fluorescent signals obtained
during FME with Confocal laser endomicroscopy (CLE);
• To assess the (sub)-cellular location of bevacizumab-800CW by ex vivo
fluorescence microscopy;
• To compare the fluorescence intensity and tumor-to-background ratio (TBR) of
the fluorescent tracer bevacizumab-800CW before and after nCRT;
• To correlate in vivo and ex vivo Optical Frequency Domain Imaging (OFDI)
images to histopathological analysis;
• Validation of Single fiber reflection / single fiber fluorescence (SFR/SFF)
spectroscopy to distinguish between positive and negative lymph nodes;
• Correlation of SFR/SFF spectroscopy measurements to cytology results.
• The safety of using SFR/SFF spectroscopy during ultrasound-guided FNA by
monitoring (serious) adverse events related to this measurement.
• To determine the most optimal dose of bevacizumab-800CW for fluorescence
molecular endoscopy.

This current study is a non-randomized, non-blinded, prospective and
single-center feasibility study. Thirty patients previously diagnosed with a
locally advanced EAC scheduled to undergo neoadjuvant chemoradiotherapy
followed by surgery in the University Medical Center Groningen (UMCG) will be
included in this study.

For this study, patients will undergo generally two endoscopic procedures at
different time-points: (1) before the start of nCRT, which is optional for
included patients and (2) after nCRT but before surgery as part of the normal
clinical workflow. The second endoscopy will be arranged on the day of
admission.

During the standard clinical endoscopie, HD-WL and EUS will be used to identify
and stage the cancer. Afterwards, fluorescence molecular endoscopy is
performed, followed by MDSFR/spectroscpie measurements on both fluorescent and
normal tissue and OFDI imaging of the esophagus and finally confocal laser
endomicroscopie (CLE). All fiberbundels or probes can be inserted through the
working channel of the clinical endoscope.
Besides the endoscopic measurements, also fluorescent measurements will be
performed on the resected surgical specimen.

An interim analysis will be performed after the first 5 patiënts to evaluate
the primary endpoints before continuing the study.

NB. Patients enrolled in our clinical trial may also be enrolled in the PRIDE
study.
The PRIDE study (NL62881.041.17) is an ongoing multicenter observational study
directed by the UMCU. The primary objective is to evaluate pCR after nCRT in
locally advanced esophageal cancer, by integrating magnetic resonance imaging
(MRI) in conjunction with combined 18F-fluorodeoxyglucose positron emission
tomography and computed tomography (18F-FDG PET-CT) scans acquired prior to,
during and after administration of nCRT.

Patients will undergo optimally two fluorescence endoscopies: before and after
nCRT.
The patients involved will receive an intravenous administration of
bevacizumab-800CW at the dosage of 4.5mg three days before the endoscopy
procedure. Vital signs, such as heart rate, blood pressure, temperature and
respiratory rate will be measured before injection, directly after injection
and an hour after injection

Endoscopy procedure
Both endoscopies will be performed by dedicated endoscopists. The endoscopy
will start with HD-WL endoscopy to focus on the lesion, followed by inserting
different fibers through the working channel of the clinical endoscope, FME and
CLE will be conducted to observe the fluorescence signals macroscopically (FME)
and, microscopically (CLE). MDSFR-SFF spectroscopy will be conducted to
quantify the fluorescence signals in vivo and ex vivo. An OFDI catheter will be
introduced to perform optical frequency domain imaging (OFDI). Subsequently,
EUS is performed. If fine needle aspiration (FNA) biopsy is taken, SFR/SFF
spectroscopy measurements will be performed on the lymph nodes.
In addition, biopsies will be taken during the endoscopy procedure. A maximum
of 16 biopsies will be taken in order to directly correlate fluorescence with
histology: 8 from the tumor, at most 4 from normal tissue and 4 from additional
fluorescence lesions when present.

Time investment
Two extra visits to UMCG are needed for patients involved in this study. The
extra visits include the first and the second tracer administration which takes
about two hours each time. The first endoscopy will be planned during a
standard clinical gastroscopy and the second during patient submission for the
surgery.

Risks
The administration risks of bevacizumab-800CW are reported in the IMPD (version
5.0, Jan. 2018, section 2.4, page 44). No adverse events were reported from
previous administrations with bevacizumab-800CW with more than 120 patients
included. Due to fluorescence imaging (FME+ MDSFR/SFF+ CLE) and OCT, the
endoscopy will be prolonged for 20 to 30 minutes. As the fiber of FME or
MDSFR/SFF, SFR/SFF, OCT, CLE or OCT can be inserted through the working channel
of HD-WL endoscope, the risks of fluorescence imaging is comparable to HD-WL
endoscopy. The biopsy procedure may cause some bleeding which often can be
treated by the gastroenterologist. The intravenous injection and the use of a
cannula are known to carry a small risk of infection and hematoma.

Benefit
There is no direct diagnostic or treatment benefit for the patients as all
procedures are processed following standard clinical guidance. No decisions
according to clinical care will be based on study results.