The early results from a first-in-human clinical trial suggest that a novel copper-based PET imaging agent may deliver clearer and more comprehensive scans for people living with neuroendocrine tumors (NETs).
The imaging tracer, called 61Cu-TraceNET™, was found to be well tolerated and produced superior image quality compared to the current standard gallium-68 PET scans. The tracer also identified additional liver and lung lesions that standard imaging methods missed.
The early study results were shared in October 2025 at the 2025 European Association of Nuclear Medicine (EANM) Congress in Barcelona, Spain.
Developed by Nuclidium AG, a radiopharmaceutical company based in Switzerland, 61Cu-TraceNET™ targets somatostatin receptors, proteins commonly found on the surface of NET cells.
About the Clinical Trial
The ongoing Phase I/II study is evaluating the safety, biodistribution, and image quality of 61Cu-TraceNET™, a copper-61–radiolabeled somatostatin receptor subtype 2 (SSTR2) antagonist, in patients with well-differentiated gastroenteropancreatic and lung NETs. The new tracer is being directly compared with the current standard-of-care PET tracer, 68Ga-DOTATOC, which is widely used today to detect NETs.
In the first 22 participants who received the new tracer, 61Cu-TraceNET™ was well tolerated, and no serious side effects were reported. The scans showed that there was higher tumor uptake and greater image quality when compared to the standard tracer, which helped clinicians spot additional tumors in the liver and lungs that other scans had missed. In addition, reviewers who examined the images without knowing which tracer was used rated those from 61Cu-TraceNET™ as superior at both one and three hours after tracer injection.
“These first-in-human data show the strong potential of copper-based radiopharmaceuticals to transform diagnosis and management in NETs,” said Dr. Guillaume Nicolas, Deputy Head of Nuclear Medicine at the University Hospital Basel, who presented the study results at EANM. “The improved image quality and excellent safety profile of 61Cu-TraceNET™ offer new possibilities for clinicians to detect and track disease more accurately.”
What This Means for Patients
While the early results of the 61Cu-TraceNET™ study are encouraging, this imaging agent is still in clinical development and not yet available for routine use. The findings from the study are preliminary and based on a small group of participants. Larger trials are needed to further explore whether the tracer has advantages over current imaging methods.
If future studies continue to show benefit, 61Cu-TraceNET™ could eventually provide clinicians with a more precise and accessible tool for detecting and monitoring neuroendocrine cancer.
From NETRF Seed Support to Clinical Impact
The success of this study stems from the early support NETRF provided with a 2022 Investigator Award to Dr. Melpomeni Fani and her research team at the University Hospital Basel. This project aimed to explore whether a copper-61-based PET tracer could improve NET imaging while making advanced scans more affordable and accessible to patients worldwide.
The NETRF support enabled these investigators to establish copper-61 production sites in both Zurich, Switzerland and Munich, Germany, while also developing standardized manufacturing practices for the new tracer. The team also secured regulatory and ethical approvals to initiate a small study of the tracer in Switzerland. Within months, they completed enrollment for the initial Phase 0/I trial, confirming the compound’s safety and feasibility.
These milestones paved the way for the current trial now underway, an important step toward bringing Dr. Fani’s innovation closer to clinical use.
What Comes Next
The promising findings from the current trial also support the development of a copper-based theranostic platform, combining diagnostic and therapeutic applications using structurally identical compounds.
Nuclidium says it plans to launch a companion therapeutic trial with 67Cu-TraceNET™ in 2026, applying the “see what you treat, and treat what you see” concept to neuroendocrine and other SSTR2-positive cancers.