Kit-based labeling of anti-CEA nanobodies for in vivo imaging and therapy of colorectal cancer

In Belgium, colorectal cancer is the third most diagnosed cancer in men and second most diagnosed cancer in women. For efficient treatment and follow-up of patients, it is important to know if the cancer has spread to distant sites (metastases). Positron emission tomography (PET) uses a scanner to track radioactive molecules in the body. Fluorine-18 (18F, a radioactive form of fluorine) is the radionuclide of choice for PET. However, the most used fluorine-18 labeled molecule, [18F]FDG, has limited specificity for the detection of colorectal cancer. Therefore, the development of novel, more specific fluorine-18 labeled tracers is highly needed. Nanobodies (Nbs) are small proteins that can specifically target colorectal cancer cells (anti-CEA Nb). They are sometimes called “magic bullets” for imaging and therapy. Nevertheless, the incorporation of fluorine-18 and therapeutic radionuclides (e.g. astatine-211) in these proteins is challenging. In this project, the aim is to develop a mild labeling method that allows rapid and efficient labeling of Nbs, while reducing kidney retention. The same labeling method will also be used for the incorporation of therapeutic radionuclides (astatine-211), which will destroy cancer cells when the Nb binds to them. The labeled Nbs will be fully evaluated and ready for clinical translation by the end of this project. In conclusion, this project will result in a more accurate staging, treatment and follow-up of colorectal tumor patients.