Pharmaceutical Development of Innovative Russian Radiopharmaceuticals Based on Bispecific Nanoantibodies to Gitr and Ctla-4 for the Theranostics of Oncological Diseases

The pharmaceutical development of innovative radiopharmaceuticals (RPs) based on bispecific high-affinity hypervariable fragments of single-domain monoclonal antibodies (nanoantibodies) to the surface receptors of T-regulatory cells (GITR and CTLA-4) is described: 68 Ga-DFO-anti-CTLA4-GITR and 177 Lu-DOTA-anti-CTLA4-GITR. The specified RPs are intended for diagnostics using the immuno-PET method ( 68 Ga-DFO-anti-CTLA4-GITR) and systemic radiation therapy ( 177 Lu-DOTA-anti-CTLA4-GITR) of the generalized forms of socially significant cancer. As part of pharmaceutical development, technologies are created for introducing chelating groups into the bispecific nanoantibody molecule, as well as methods for obtaining the main active substance and the finished dosage form of the radioactive drug with selection of the optimal composition of excipients to ensure the stability of the radionuclide complex and the precursor molecule.