Small molecule and peptide-based radiotracer for PET-Imaging of TME receptors
Therapies using immune checkpoint inhibitors to block e.g. PD-L1 or CTLA-4 offer a promising therapeutic approach for cancer patients. However, on average only 30% of patients respond to checkpoint inhibitor monotherapy. In order to select those patients prior to therapy who will likely respond, non-invasive, molecular imaging techniques such as PET and SPECT are particularly suitable, since they can address the problem of heterogeneous expression of different checkpoints over time. Therefore, small organic molecules and low-molecuar-weight peptides as well as peptidomimetics are synthesized, modified and labeled with a radionuclide (fluorine-18, gallium-68) by applying the full array of medicinal radiochemistry methods to meet the criteria for a radiotracer. These new radioligands are tested both in vitro on tumor cell lines and in vivo in animal models (µPET, µSPECT and organ distribution of tumor-bearing small animals) with regard to their use in nuclear medicine.