DOTA-LM3 is a somatostatin receptor (SSTR) antagonist. LM3 refers to p-Cl-Phe- cyclo(D-Cys-Tyr-D-4-amino-Phe(carbamoyl)-Lys-Thr-Cys)D-Tyr- NH2, as well as a somatostatin antagonist. DOTA-LM3 is often isotopically labeled for tracing tumors in vivo, such as 177Lu-DOTA-LM3 and 68 Ga-DOTA-LM3. 68 Ga-DOTA-LM3 shows favorable biodistribution, high tumor uptake, good tumor retention, and few safety concerns. 177Lu-DOTA-LM3 can be used for research in DOTATOC-negative liver metastases, such as pancreatic NET and extensive tumor thrombosis.
177Lu-DOTA-LM3 is tolerated. 177Lu-DOTA-LM3 in the whole body and in the kidneys, spleen, and metastases, resulting in higher mean absorbed organ and tumor doses[2].
References:
[1]. Zhu W, et al. A prospective randomized, double-blind study to evaluate the diagnostic efficacy of 68Ga-NODAGA-LM3 and 68Ga-DOTA-LM3 in patients with well-differentiated neuroendocrine tumors: compared with 68Ga-DOTATATE. Eur J Nucl Med Mol Imaging. 2022 Apr;49(5):1613-1622.
[2]. Baum RP, et al. First-in-Humans Study of the SSTR Antagonist 177Lu-DOTA-LM3 for Peptide Receptor Radionuclide Therapy in Patients with Metastatic Neuroendocrine Neoplasms: Dosimetry, Safety, and Efficacy. J Nucl Med. 2021 Nov;62(11):1571-1581.