1. Academic Validation
  2. Therapeutic Radiopharmaceuticals Targeting Integrin αvβ6

Therapeutic Radiopharmaceuticals Targeting Integrin αvβ6

  • ACS Omega. 2018 Feb 28;3(2):2428-2436. doi: 10.1021/acsomega.8b00035.
Stefanie Felicitas Färber 1 Alexander Wurzer 1 Florian Reichart 1 Roswitha Beck 1 Horst Kessler 1 Hans-Jürgen Wester 1 Johannes Notni 1
Affiliations

Affiliation

  • 1 Lehrstuhl für Pharmazeutische Radiochemie and Institute for Advanced Study and Center of Integrated Protein Science (CIPSM), Department of Chemistry, Technische Universität München, Garching D-85748, Germany.
Abstract

The epithelial Integrin αvβ6 is expressed by many malignant carcinoma cell types, including pancreatic Cancer, and thus represents a promising target for radionuclide therapy. The peptide cyclo(FRGDLAFp(NMe)K) was decorated with different chelators (DOTPI, DOTAGA, and DOTA). The Lu(III) complexes of these conjugates exhibited comparable αvβ6 Integrin affinities (IC50 ranging from 0.3 to 0.8 nM) and good selectivities against Other integrins (IC50 for αvβ8 >43 nM; for α5β1 >238 nM; and for αvβ3, αvβ5, and αIIbβ3 >1000 nM). Although different formal charges of the Lu(III) chelates (ranging from 0 to 4) resulted in strongly varying degrees of hydrophilicity (log D ranging from -3.0 to -4.1), biodistributions in murine H2009 xenografts of the Lu-177-labeled compounds (except the DOTPI derivative) were quite similar and comparable to our previously reported αvβ6 Integrin positron emission tomography tracer Ga-68-avebehexin. Hence, combinations of existing Ga-68- and Lu-177-labeled c(FRGDLAFp(NMe)K) derivatives could be utilized for αvβ6 integrin-targeted theranostics, whereas our data nonetheless suggest that further improvement of pharmacokinetics might be necessary to ensure clinical success.

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