Research ArticleBrief Communication
Open Access

First-in-Human Serum Stability Studies of [177Lu]Lu-AMTG: A Step Toward Improved GRPR-Targeted Radiopharmaceutical Therapy

Veronika Felber, Nadine Holzleitner, Markus Joksch, Tim Suhrbier, Gunhild von Amsberg, Sarah Schwarzenböck, Jens Kurth, Martin Heuschkel, Thomas Günther and Bernd J. Krause
Journal of Nuclear Medicine April 2025, jnumed.124.269132; DOI: https://doi.org/10.2967/jnumed.124.269132

Article Figures & Data

Figures

  • Figure
  • FIGURE 1.
    FIGURE 1.

    Chemical structures of RM2 and AMTG displaying major cleavage site (depicted in red) ubiquitously present in bombesin-based compounds and stabilizing moiety (α-methyl-L-tryptophan, depicted in blue).

  • FIGURE 2.
    FIGURE 2.

    Exemplary radio–RP-HPLC chromatograms displaying intact [177Lu]Lu-AMTG (retention time, ∼14.5 min) as well as 2 metabolites (retention times, ∼5.4 and ∼15.7 min) in human serum over time. p.i. = postinjection; QC = quality control.

  • FIGURE 3.
    FIGURE 3.

    Comparison of in vivo stability of [177Lu]Lu-AMTG (n = 4; mean ± SD dose, 67 ± 3 GBq/μmol) and [68Ga]Ga-RM2 (n = 5; mean ± SD dose, ∼11 ± 3 GBq/μmol) in human serum at various time points after injection into human subjects. *Data from Roivainen et al. (8).

  • FIGURE 4.
    FIGURE 4.

    Uptake of [68Ga]Ga-AMTG and [177Lu]Lu-AMTG in 70-y-old patient with mCRPC with insufficient PSMA uptake and exhausted treatment options. Coronal section of pretherapeutic [68Ga]Ga-AMTG PET/CT image (left) displays pronounced uptake in osseous metastases, including in ilium and femoral neck and shaft. Intratherapeutic [177Lu]Lu-AMTG SPECT/CT image (right) at 1, 24, 48, and 66 h after injection shows intense and persistent activity retention in these lesions. All images were identically scaled to SUVs. p.i. = postinjection.

Additional Files

Back to top

In this issue

Print
Download PDF
Article Alerts
Email Article
Citation Tools
Bookmark this article

Jump to section

Keywords