Radionuclide therapy using ABD-fused ADAPT scaffold protein: Proof of Principle

Javad Garousi, Emma von Witting, Jesper Borin, Anzhelika Vorobyeva, Mohamed Altai, Olga Vorontsova, Mark W. Konijnenberg, Maryam Oroujeni, Anna Orlova, Vladimir Tolmachev, Sophia Hober

Research output: Contribution to journalArticlepeer-review


Molecular recognition in targeted therapeutics is typically based on immunoglobulins. Development of engineered scaffold proteins (ESPs) has provided additional opportunities for the development of targeted therapies. ESPs offer inexpensive production in prokaryotic hosts, high stability and convenient approaches to modify their biodistribution. In this study, we demonstrated successful modification of the biodistribution of an ESP known as ADAPT (Albumin-binding domain Derived Affinity ProTein). ADAPTs are selected from a library based on the scaffold of ABD (Albumin Binding Domain) of protein G. A particular ADAPT, the ADAPT6, binds to human epidermal growth factor receptor type 2 (HER2) with high affinity. Preclinical and early clinical studies have demonstrated that radiolabeled ADAPT6 can image HER2-expression in tumors with high contrast. However, its rapid glomerular filtration and high renal reabsorption have prevented its use in radionuclide therapy. To modify the biodistribution, ADAPT6 was genetically fused to an ABD. The non-covalent binding to the host's albumin resulted in a 14-fold reduction of renal uptake and appreciable increase of tumor uptake for the best variant, 177Lu-DOTA-ADAPT6-ABD035. Experimental therapy in mice bearing HER2-expressing xenografts demonstrated more than two-fold increase of median survival even after a single injection of 18 MBq 177Lu-DOTA-ADAPT6-ABD035. Thus, a fusion with ABD and optimization of the molecular design provides ADAPT derivatives with attractive targeting properties for radionuclide therapy.

Original languageEnglish
Article number120381
Publication statusPublished - Jan 2021


  • Lu
  • ABD (Albumin binding domain)
  • ADAPT (Albumin-binding domain derived affinity ProTein)
  • Biodistribution modification
  • HER2
  • Radionuclide therapy

ASJC Scopus subject areas

  • Bioengineering
  • Ceramics and Composites
  • Biophysics
  • Biomaterials
  • Mechanics of Materials

Fingerprint Dive into the research topics of 'Radionuclide therapy using ABD-fused ADAPT scaffold protein: Proof of Principle'. Together they form a unique fingerprint.

Cite this