Logo image
[ 203/212 Pb]Pb-VMT-α-NET as a novel theranostic agent for targeted alpha radiotherapy-first clinical experience
Journal article   Peer reviewed

[ 203/212 Pb]Pb-VMT-α-NET as a novel theranostic agent for targeted alpha radiotherapy-first clinical experience

Enrico Michler, David Kästner, Marc Pretze, Holger Hartmann, Robert Freudenberg, Michael K Schultz, Ralph A Bundschuh, Jörg Kotzerke and Claudia Brogsitter
European journal of nuclear medicine and molecular imaging, Vol.52(11), pp.4171-4183
09/2025
DOI: 10.1007/s00259-025-07269-0
PMCID: PMC12397198
PMID: 40202686

View Online

Abstract

Pb is a promising theranostic isotope pair for targeted alpha therapy (TAT) of neuroendocrine tumors (NET). VMT-α-NET is a novel SSTR2 targeting peptide that can be labeled with both isotopes. The aim of this work was to perform first clinical investigations of [ Pb]Pb-VMT-α-NET regarding imaging, biokinetics, tolerability and response. 12 patients (9 m/3 w; mean age 71, range 60-84) with progressive metastatic GEP-NET grade 1-3 received diagnostic imaging with [ Pb]Pb-VMT-α-NET (4.9 MBq/kg bw) up to 24 h p.i. (whole body & SPECT/CT) and, if eligible, a single dose of [ Pb]Pb-VMT-α-NET therapy (1.2 MBq/kg bw) after exhaustion of all current therapies (including [ Lu]Lu- & [ Ac]Ac-DOTATATE), and post-treatment imaging with [ Pb]Pb-VMT-α-NET up to 24 h p.i. (whole body & SPECT/CT). Clinical and laboratory parameters were monitored. A visual and quantitative comparison was made with [  Ga]Ga-DOTATATE PET scans before and 3 months after therapy. No high-grade adverse effects were observed in all patients evaluated with [ Pb]Pb-VMT-α-NET. All patients showed an initial high, but lesion-dependent heterogeneous intratumoral accumulation, comparable to [  Ga]Ga-DOTATATE PET. Treatment with [ Pb]Pb-VMT-α-NET was also well tolerated by all patients without high-grade or serious adverse side effects. Post-therapeutic PET scans and tumor marker controls showed stable findings in all patients up to 3 months after treatment. Imaging with [ Pb]Pb-VMT-α-NET followed by a single dose of [ Pb]Pb-VMT-α-NET appears to be well tolerated with promising efficacy, even in a heterogenous and heavily pretreated patient population. Further studies are warranted to examine tolerability and efficacy over multiple treatment cycles in larger patient populations.
203Pb 212Pb Targeted alpha therapy Theranostic VMT-α-NET Neuroendocrine tumors

Details

Metrics

8 Record Views
Logo image