A phase 3 study from molecular imaging firm Blue Earth Diagnostics found that its Axumin contrast agent for PET scans could assist in the diagnosis of patients with glioma.
Axumin, consisting of the synthetic amino acid fluciclovine tagged with a fluoride radioisotope, has previously been approved by the FDA for PET scans of men with suspected prostate cancer recurrence, based on blood measurements of the prostate-specific antigen biomarker.
In the blinded image-evaluation study, the injection was used to visualize increases in amino acid transport in tumors such as glioma, compared to MRI scans alone, for the detection and continued assessment of the malignant brain tumors.
By using Axumin and PET to gather additional insight as an adjunct to MRI scans, the study demonstrated a positive predictive value of more than 90%, the company said. The results were presented at the annual scientific meeting of the Society for Neuro-Oncology in New Orleans.
“Guidelines from the Response Assessment in Neuro-Oncology working group and the European Association for Neuro-Oncology emphasize the clinical value of PET imaging with superiority of amino acid PET over glucose PET and provides a framework for the use of PET to assist in the management of patients with glioma,” said lead study author Matthew Miller, head of imaging at Blue Earth.
“Additionally, 18F-fluciclovine PET with MRI identified additional regions suspicious for glioma that MRI alone was unable to identify, which subsequent biopsies confirmed as malignant,” Miller added.
The prospective study used 35 Axumin datasets derived from a previous prospective phase 2 study evaluating the efficacy the PET agent and MRI in adults with glioma. Three independent, blinded readers assessed images captured by cranial PET scan, an average of 13.1 minutes after the injection.
The sensitivity of Axumin with MRI, which ranged from 65.8% to 71.1%, was higher than MRI alone, at 42.1%. However it was not as high as fluid-attenuated inversion recovery MRI—also known as FLAIR or T2-weighted MRI—which reached 86.8% sensitivity.
“18F-fluciclovine PET is designated as an orphan drug by the FDA and EMA for the diagnosis of glioma, and Blue Earth Diagnostics is investigating its potential use in adults with glioma as part of our mission to develop and commercialize innovative PET imaging agents to address unmet medical needs in cancer,” Blue Earth CEO Jonathan Allis said in a statement, describing plans to publish the full results in an upcoming journal.