Development of a new class of radiopharmaceuticals for diagnosis and therapy of CXCR4-expressing malignancies based on the endogenous CXCR4 antagonist EPI-X4

• Applicant: Professor Dr. Jan Münch
• Subject Area: Pharmacy ; Nuclear Medicine, Radiotherapy, Radiobiology
• Term: from 2020 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 441271438

• Final Report Year: 2024

Final Report Abstract

The project aimed to develop a new class of radiopharmaceuticals for the diagnosis and treatment of CXCR4-expressing malignancies using EPI-X4 as a scaffold. CXCR4 is a receptor found in about 65% of all cancers, making it a critical target for therapeutic intervention. The goal was to create radioligands that are more specific, better tolerated, and have fewer off-target effects compared to existing CXCR4-targeting molecules. This approach is aligned with the principles of precision medicine, allowing for non-invasive detection and targeted radionuclide therapy of CXCR4-expressing cancers. Significant scientific advances were achieved during the project. The development and optimization of stabilized EPI-X4 derivatives, which were conjugated with DOTA for radiolabeling, was a key milestone. These modifications, including the introduction of nonnatural amino acids and D-amino acids at the N-terminus, greatly enhanced the stability of the radioligands in plasma. Among the developed compounds, 177Lu-7 emerged as the lead candidate due to its favorable biodistribution and high metabolic stability, with reduced uptake in non-target organs like the liver and kidneys. The project involved extensive in vitro and in vivo evaluations. In vitro assays demonstrated high affinity of the radioligands for CXCR4, with ligand-9 showing the highest affinity. In vivo studies using SPECT/CT and PET/CT imaging in mice with CXCR4-expressing tumors confirmed the theragnostic potential of 177Lu-7/68Ga-7, which exhibited low uptake in nontarget organs and effective tumor targeting. One of the unexpected findings in the project was the discrepancy between in vitro and in vivo results, particularly concerning the cellular uptake of ligand-7. This ligand showed the highest uptake in vitro but behaved differently in some in vivo contexts, prompting further investigation and optimization. Despite meeting the project's initial milestones, the decision was made to continue optimizing ligand-7 to increase the chances of successful clinical translation. In conclusion, the project has achieved substantial scientific progress in developing targeted cancer therapies. The creation and optimization of CXCR4-targeting radioligands based on EPI-X4 lay a solid foundation for future clinical applications. The project's ability to adapt and overcome challenges has positioned it well for making a significant impact in the field of cancer treatment.

Publications

• An optimized derivative of an endogenous CXCR4 antagonist prevents atopic dermatitis and airway inflammation. Acta Pharmaceutica Sinica B, 11(9), 2694-2708.
  Harms, Mirja; Habib, Monica M.W.; Nemska, Simona; Nicolò, Antonella; Gilg, Andrea; Preising, Nico; Sokkar, Pandian; Carmignani, Sara; Raasholm, Martina; Weidinger, Gilbert; Kizilsavas, Gönül; Wagner, Manfred; Ständker, Ludger; Abadi, Ashraf H.; Jumaa, Hassan; Kirchhoff, Frank; Frossard, Nelly; Sanchez-Garcia, Elsa & Münch, Jan
  
• Computational modeling and experimental validation of the EPI-X4/CXCR4 complex allows rational design of small peptide antagonists. Communications Biology, 4(1).
  Sokkar, Pandian; Harms, Mirja; Stürzel, Christina; Gilg, Andrea; Kizilsavas, Gönül; Raasholm, Martina; Preising, Nico; Wagner, Manfred; Kirchhoff, Frank; Ständker, Ludger; Weidinger, Gilbert; Mayer, Benjamin; Münch, Jan & Sanchez-Garcia, Elsa
  
• Dimerization of the Peptide CXCR4-Antagonist on Macromolecular and Supramolecular Protraction Arms Affords Increased Potency and Enhanced Plasma Stability. Bioconjugate Chemistry, 33(4), 594-607.
  Harms, Mirja; Hansson, Rikke Fabech; Carmali, Sheiliza; Almeida-Hernández, Yasser; Sanchez-Garcia, Elsa; Münch, Jan & Zelikin, Alexander N.
  
• Development of a New Class of CXCR4-Targeting Radioligands Based on the Endogenous Antagonist EPI-X4 for Oncological Applications. Journal of Medicinal Chemistry, 66(13), 8484-8497.
  Gaonkar, Raghuvir Haridas; Schmidt, Yannik Tim; Mansi, Rosalba; Almeida-Hernandez, Yasser; Sanchez-Garcia, Elsa; Harms, Mirja; Münch, Jan & Fani, Melpomeni
  
• Development of N-Terminally Modified Variants of the CXCR4-Antagonistic Peptide EPI-X4 for Enhanced Plasma Stability. Journal of Medicinal Chemistry, 66(22), 15189-15204.
  Harms, Mirja; Fabech, Hansson Rikke; Gilg, Andrea; Almeida-Hernández, Yasser; Löffler, Jessica; Rodríguez-Alfonso, Armando; Habib, Monica M. W.; Albers, Dan; Ahmed, Nermin S.; Abadi, Ashraf H.; Winter, Gordon; Rasche, Volker; Beer, Ambros J.; Weidinger, Gilbert; Preising, Nico; Ständker, Ludger; Wiese, Sebastian; Sanchez-Garcia, Elsa; Zelikin, Alexander N. & Münch, Jan
  
• Spermine and spermidine bind CXCR4 and inhibit CXCR4- but not CCR5-tropic HIV-1 infection. Science Advances, 9(27).
  Harms, Mirja; Smith, Nikaïa; Han, Mingyu; Groß, Rüdiger; von Maltitz, Pascal; Stürzel, Christina; Ruiz-Blanco, Yasser B.; Almeida-Hernández, Yasser; Rodriguez-Alfonso, Armando; Cathelin, Dominique; Caspar, Birgit; Tahar, Bouceba; Sayettat, Sophie; Bekaddour, Nassima; Vanshylla, Kanika; Kleipass, Franziska; Wiese, Sebastian; Ständker, Ludger; Klein, Florian ... & Münch, Jan