Biodistribution and Safety of 18F-FP-R01-MG-F2 Knottin PET Tracer in Patients with Pancreatic Cancer

1008 Purpose: 18F-FP-R01-MG-F2 is a novel cystine knot peptide (knottin) PET tracer that selectively binds to human integrin αvβ6. This integrin cell surface receptor is over-expressed in pancreatic cancer, as well as other malignancies. Here, we report the biodistribution and safety of 18F-FP-R01-MG-F2 in patients with pancreatic cancer. Methods: Fourteen patients (5 men, 9 women) with histologically confirmed pancreatic cancer were prospectively enrolled between March 2017 and November 2020. Maximum standardized uptake values (SUVmax) and mean SUV (SUVmean) were measured in 21 normal tissues for each patient using PET/CT images at 60 minutes post-injection of 18F-FP-R01-MG-F2. Vital signs and laboratory results were collected before and after the PET scans. Results: Areas of high 18F-FP-R01-MG-F2 uptake (SUVmax range: 8.0 - 52.1, SUVmean range: 6.2 - 30.2) included the pituitary gland, stomach, duodenum, and kidneys. Moderate to high uptake (SUVmax range: 2.5 - 19.1, SUVmean range: 1.6 - 13.0) was found in the normal pancreas. Mild uptake (SUVmax range: 0.5 - 2.2, SUVmean range: 0.3 - 1.5) was found in the lung and liver. There were no significant changes in vital signs or laboratory values that qualified as adverse events. 18F-FP-R01-MG-F2 PET/CT detected all known pancreatic tumors in the 14 patients, although it did not detect small peri-pancreatic lymph nodes in two of three patients who were found to have lymph node metastases after surgery. 18F-FP-R01-MG-F2 PET/CT detected lung and/or liver metastases in all five patients who were confirmed to have distant metastases by contrast-enhanced CT. Conclusions: 18F-FP-R01-MG-F2 is shown to be a safe PET radiopharmaceutical with high uptake in primary and metastatic pancreatic cancer lesions.