BiOrion is a clinical stage biopharmaceutical company developing combined PET-imaging diagnostics and targeted radionuclide therapeutics (theranostics) for millions of patients suffering from fibrosis or fibrotic cancers. We have developed high-affinity binding single domain antibodies to PDGF-beta-receptors that appear on activated myofibroblasts in fibrotic tissue. Most companies that have developed fibrosis diagnostics focus on the deposition of extracellular matrix proteins, such as collagen. BiOrion, on the other hand, believes that fibrogenesis (fibrosis activity) is a far more reliable parameter to asses fibrosis than collagen deposition. We have shown that the PDGF-beta-receptor is a sensitive biomarker of fibrogenesis. The receptor not only appears on myofibroblast in the early phase of fibrogenesis but, interestingly, also disappears quickly during fibrolysis. The PET image is therefore reflecting the expression level of PDGF beta receptors in the fibrotic organ in both directions. Our single domain antibodies, labeled with 68Gallium, are therefore attractive non-invasive PET imaging tools to diagnose fibrogenesis. Moreover, it is a much faster diagnostic tool to determine the effectivity of antifibrotic therapies. Eventually this would speed up the development of novel antifibrotic therapies. Several metastasizing cancers rely on fibrotic stroma that share similar biology as organ fibrosis. These cancers can also be diagnosed by PET imaging of PDGF beta receptor rich stroma tissue with 68Gallium. Moreover, exchanging 68Gallium for 177Lutetium, allows use of the single domain antibody as a targeted radiotherapeutic. This could be especially attractive for advanced colon cancer metastases to the liver.
