Clarity Pharmaceuticals (ASX:CU6) has taken a step toward regulatory approval of its diagnostic imaging agent, announcing it will commence a pivotal Phase 3 trial of Cu-64 SARTATE in patients with neuroendocrine tumours (NETs) following positive guidance from the U.S. Food and Drug Administration.
The company said the decision follows a successful End of Phase meeting with the FDA, at which all key elements of the proposed trial design were agreed upon. Recruitment into the registrational study is expected to begin in 2026, positioning Clarity to advance Cu-64 SARTATE toward a potential U.S. marketing application.
The Phase 3 trial will be a multi-centre, single-arm, non-randomised, open-label diagnostic study involving approximately 70 participants. As a registrational trial, its final results are intended to support an application to the FDA for approval of Cu-64 SARTATE as a new PET imaging agent for NETs.
The study builds on an expanding body of clinical evidence, including Clarity’s first-in-human CL01 trial and the Phase 2 DISCO trial, which demonstrated that Cu-64 SARTATE was safe and well-tolerated, with lesion detection substantially higher than the current standard of care, Ga-68 DOTATATE. Notably, the DISCO trial showed enhanced detection of liver metastases—the most common metastatic site in gastroenteropancreatic NETs and a key determinant of patient prognosis and treatment planning. Data from the DISCO study have been accepted for presentation at the ASCO Gastrointestinal Cancers Symposium in January 2026.
Neuroendocrine tumours are often slow-growing and difficult to diagnose, with patients frequently experiencing delays of several years before confirmation. As a result, a significant proportion present with metastatic disease at diagnosis, underscoring the clinical importance of more sensitive and accurate imaging tools.
Clarity’s Executive Chairperson, Dr Alan Taylor, said the FDA’s guidance represents a pivotal milestone for the company and its Targeted Copper Theranostics platform.
He said progressing to a third registrational trial highlights Clarity’s commitment to advancing its pipeline in areas of high unmet medical need, and reflects the company’s confidence in the clinical advantages of Cu-64 SARTATE over existing imaging agents.
Cu-64 SARTATE is part of Clarity’s broader SARTATE theranostic platform, which pairs copper-64 for diagnostic imaging with copper-67 for targeted radiotherapy. The company believes that improved diagnostic precision will ultimately enable clinicians to make more informed treatment decisions, paving the way for better outcomes in patients with NETs.