Studies of the 18F L-glutamate derivative BAY 94-9392 in cancer patients: A novel radiopharmaceutical for PET imaging

1900 Objectives BAY 94-9392 ((S)-4-(3-[18F]Fluoropropyl)-L-glutamic acid) is a novel radiopharmaceutical developed by Bayer HealthCare Pharmaceuticals, Inc. for PET imaging (FDA eIND 108509). It is a glutamate analogue and shows promise for oncologic imaging. We present data on the first subjects imaged with prostate (PR,2), head and neck (HN,1), and colorectal cancers (CRC,1). Methods Approximately 8 mCi of BAY 94-9392 was given IV to the 4 subjects (median age: 59 ± 10 years) and 3 PET/CT scans were obtained 0-2 hours post-injection. During this time, vitals, EKGs, and blood samples were obtained. Two subjects also had a FDG PET/CT scan within 1 month. SUV and visual comparison of the BAY 94-9392 and FDG scans were performed to assess relative efficacy of the tracers. Results BAY 94-9392 did not cause alterations in symptoms, vitals, EKGs, or lab values. There was similar distribution in all patients with primary clearance through the kidneys. Quantitatively, all the malignant lesions were positive on BAY 94-9392 but with a range of uptake (see table). The comparative FDG scans showed either similar or slightly higher uptake. Visually, BAY 94-9392 showed comparable uptake to FDG in the HN and CRC subjects while uptake in the PR subjects was mild, but focal. Additionally, the background uptake in the BAY 94-9392 scans was lower than FDG. Conclusions BAY 94-9392 was well tolerated and showed increased uptake in the 4 tumor types evaluated. Lower background uptake (than FDG) in the BAY 94-9392 scans may beneficial. These results are promising and warrant further analysis