Signore Alberto, Galli Filippo, Varani Michela, Campagna Giuseppe, Bentivoglio Valeria, Accardo Antonella, Morelli Giancarlo, Lauri Chiara
Nuclear Medicine Unit, Department of Medical-Surgical Sciences and of Translational Medicine, Faculty of Medicine and Psychology, "Sapienza" University, Rome, Italy.
Nuclear Medicine Unit, Sant'Andrea University Hospital, Via di Grottarossa 1035, Rome, 00189, Italy.
Eur J Nucl Med Mol Imaging. 2025 Jul 1. doi: 10.1007/s00259-025-07430-9.
This study aimed to develop a ready-to-use kit for Ga-labelling of interleukin-2 (IL2) facilitating PET imaging of activated T-lymphocytes.
Human recombinant IL2 (hrIL2) and Aldesleukin (desIL2), conjugated with two different chelators (NODAGA and THP) were compared. Conjugated-IL2 was stored, freeze-dried at -80 °C and radiolabelled at room temperature. In vitro quality controls (iTLC, HPLC, SDS-PAGE, spectrometry and binding assays on activated T-lymphocytes) and in vivo biodistribution studies in BALB/c mice, were performed. The shelf life of the lyophilized kits was assessed up to 6 months of storage, by iTLC, HPLC and SDS-PAGE. First-in-human study was conducted in 5 volunteers by performing [Ga]Ga-THP-desIL2 PET/CT acquisitions at several time-points, to assess biodistribution and dosimetry.
Mass spectrometry showed that only one molecule of THP or NODAGA is bound to N-terminus of both IL2 proteins. The most efficient conjugation was observed for THP-desIL2. [Ga]Ga-THP-desIL2 showed higher labelling yield (LY) (59.13 ± 2.58%), radiochemical purity (RCP) (97.91 ± 0.45%) and binding affinity to its receptor on activated T-cells (Kd = 0.584 nM/L) and a more favorable biodistribution in pre-clinical studies, with rapid kidney metabolism and lower liver uptake than [Ga]Ga-NODAGA-desIL2 and [Ga]Ga-THP-hrIL2. Lyophilized kit of THP-desIL2 remained stable at -80 °C up to 6 months maintaining high RCP and LY. Phase I study showed a rapid plasma clearance, renal metabolism, safety and favorable dosimetry.
We developed an efficient lyophilized kit of THP-desIL2 for Ga-labelling at room temperature in GMP conditions, obtaining excellent in vitro and in vivo results. [Ga]Ga-THP-desIL2 PET/CT studies in humans showed favorable dosimetry and safety, thus highlighting its potential for a wide range of clinical applications, particularly in immune-mediated diseases and cancer.
本研究旨在开发一种即用型试剂盒，用于白细胞介素-2（IL2）的镓标记，以促进活化T淋巴细胞的PET成像。
比较了与两种不同螯合剂（NODAGA和THP）缀合的人重组IL2（hrIL2）和阿地白介素（desIL2）。将缀合的IL2储存，在-80°C冻干，并在室温下进行放射性标记。进行了体外质量控制（iTLC、HPLC、SDS-PAGE、光谱分析以及对活化T淋巴细胞的结合测定）和在BALB/c小鼠体内的生物分布研究。通过iTLC、HPLC和SDS-PAGE评估冻干试剂盒在长达6个月储存期内的保质期。在5名志愿者中进行了首次人体研究，通过在多个时间点进行[镓]Ga-THP-desIL2 PET/CT采集，以评估生物分布和剂量学。
质谱分析表明，THP或NODAGA仅一个分子与两种IL2蛋白的N端结合。观察到THP-desIL2的缀合效率最高。[镓]Ga-THP-desIL2显示出更高的标记率（LY）（59.13±2.58%）、放射化学纯度（RCP）（97.91±0.45%）以及对活化T细胞上其受体的结合亲和力（Kd = 0.584 nM/L），并且在临床前研究中具有更有利的生物分布，与[镓]Ga-NODAGA-desIL2和[镓]Ga-THP-hrIL2相比，肾脏代谢迅速且肝脏摄取较低。THP-desIL2的冻干试剂盒在-80°C下长达6个月保持稳定，维持高RCP和LY。I期研究显示出快速的血浆清除、肾脏代谢、安全性和良好的剂量学。
我们开发了一种高效的THP-desIL2冻干试剂盒，用于在GMP条件下室温下进行镓标记，获得了优异的体外和体内结果。[镓]Ga-THP-desIL2在人体中的PET/CT研究显示出良好的剂量学和安全性，从而突出了其在广泛临床应用中的潜力，特别是在免疫介导疾病和癌症方面。
