Detection of PitNET Tissue During TSS Using Bevacizumab-800CW (DEPARTURE)

Detection of Pituitary Neuroendocrine Tumor (PitNET) Tissue During Endoscopic Transsphenoidal Surgery Using Bevacizumab-800CW

There is a need for improved visualization of presence and extent of pituitary neuroendocrine tumor (PitNET) tissue during transsphenoidal surgery (TSS), especially in tumors invading the cavernous sinus (CS). Optical molecular imaging of PitNET associated biomarkers is a promising technique to accommodate this need. Vascular Endothelial Growth Factor (VEGF-A) is overexpressed in PitNET tissue compared to normal pituitary tissue and has proven to be a valid target for molecular imaging. Bevacizumab is an antibody that binds VEGF-A. By conjugating a fluorescent dye to this antibody, the fluorescent tracer molecule bevacizumab-800CW is created, which binds to VEGF-A. The investigators hypothesize that bevacizumab-800CW accumulates in PitNET tissue, enabling visualization using a molecular fluorescence endoscopy system. In this pilot intervention study the investigators will determine the feasibility of using microdoses (4.5, 10 and 25 mg) of bevacizumab-800CW to detect PitNET tissue intraoperatively.

IV-administration of 4.5 mg of the fluorescent tracer bevacizumab-800CW to 3 patients with a pituitary neuroendocrine tumor (PitNET) with a Knosp grade of 3 or 4. The optimal dose will be expanded to include 6 patients.

IV-administration of 10 mg of the fluorescent tracer bevacizumab-800CW to 3 patients with a pituitary neuroendocrine tumor (PitNET) with a Knosp grade of 3 or 4. The optimal dose will be expanded to include 6 patients.

IV-administration of 25 mg of the fluorescent tracer bevacizumab-800CW to 3 patients with a pituitary neuroendocrine tumor (PitNET) with a Knosp grade of 3 or 4. The optimal dose will be expanded to include 6 patients.

Intravenous administration of 4.5, 10 or 25 mg of Bevacizumab-IRDye800CW prior to endoscopic transsphenoidal surgery

A flexible fluorescence fiber-bundle is attached to a fluorescence camera platform to enable the detection of fluorescence signals. The fluorescence fiber-probe is inserted through the standard working channel of the Surgvision explorer endoscope. During surgery, three imaging moments are defined in which the fluorescence molecular endoscopy system will detect the fluorescent signal

Discrimination of tumorous and non-tumorous tissue based on in vivo and ex vivo fluorescence measurements from bevacizumab-800CW gained during fluorescence endoscopic transsphenoidal surgery of pituitary neuroendocrine tumors (PitNETs)

To determine the sensitivity of the marker bevacizumab-800CW in discriminating between tumorous and non-tumorous tissue during endoscopic transsphenoidal surgery of pituitary neuroendocrine tumors (PitNETs) defined as the tumor to background ratio and intrinsic fluorescence

Number of participants with adverse events (AE), serious adverse events (SAE) and suspected unexpected serious adverse reactions (SUSAR)

Data collection as a measure of safety and tolerability regarding administration of bevacizumab-800CW

Multi-diameter single-fiber reflectance with single-fiber fluorescence (MDSFR/SFF) spectroscopy can measure the fluorescence signal quantitatively, both in vivo and ex vivo

Assessment of the (sub)-cellular distribution of bevacizumab-800CW by ex vivo fluorescence microscopy

Inclusion Criteria: Patients with an established diagnosis of PitNET with a Knosp grade of 3 or 4 who are scheduled to undergo TSS. WHO performance status 0-2 Signed written informed consent Exclusion Criteria: Medical or psychiatric conditions that compromise the patient's ability to give informed consent Pregnant or lactating women. Documentation of a negative pregnancy test must be available for woman of childbearing potential. Woman of childbearing potential are pre- menopausal women with intact reproductive organs and women less than two years after menopause History of infusion reactions to bevacizumab or other monoclonal antibody therapies. Inadequately controlled hypertension with or without current antihypertensive medication Within 6 months prior to inclusion: myocardial infarction, TIA, CVA, pulmonary embolism, uncontrolled chronic hepatic failure, unstable angina pectoris

Vergeer RA, Postma MR, Schmidt I, Korsten-Meijer AG, Feijen RA, Kruijff S, Nagengast WB, van Dijk JMC, den Dunnen WFA, van Beek AP, Kuijlen JMA, van den Berg G. Detection by fluorescence of pituitary neuroendocrine tumour (PitNET) tissue during endoscopic transsphenoidal surgery using bevacizumab-800CW (DEPARTURE trial): study protocol for a non-randomised, non-blinded, single centre, feasibility and dose-finding trial. BMJ Open. 2021 Oct 7;11(10):e049109. doi: 10.1136/bmjopen-2021-049109.