Clarity’s Radiopharmaceutical Gambit Scores with DISCO Results

In the world of molecular imaging, clarity is more than just a virtue – it’s a listed entity with a copper bullet in the chamber. ASX-listed Clarity Pharmaceuticals (ASX:CU6) has posted early topline results from its Phase II DISCO trial, and by all appearances, its lead imaging agent 64Cu-SARTATE is not just safe, but a game-changer in detecting neuroendocrine tumours (NETs).

The DISCO trial (short for Diagnostic Imaging Study of 64Copper-SARTATE) set out to test whether Clarity’s radiopharmaceutical could outshine the current standard-of-care, 68Ga-DOTATATE, in identifying NET lesions using PET/CT imaging. Not only did it pass that test – it left 68Ga-DOTATATE in the radioactive dust.

Across 45 trial participants, 64Cu-SARTATE picked up between 393 and 488 lesions, compared to just 186 to 265 for 68Ga-DOTATATE. That’s close to double the detection rate, and it’s not just about quantity. Among lesions flagged by only one of the tracers – termed “discordant” – a whopping 93.5% were spotted solely by Clarity’s compound.

To ensure this wasn’t a fluke, the study used standard-of-truth (SOT) confirmations like histopathology and conventional imaging on roughly half of these discordant findings. The result? 64Cu-SARTATE achieved a lesion-level sensitivity of 93.4% to 95.6%, while 68Ga-DOTATATE limped in at 4.4% to 6.6%.

Executive Chair Dr Alan Taylor didn’t mince words in the announcement. “The DISCO trial demonstrates a significant advantage of our diagnostic over 68Ga-DOTATATE,” he said, noting the superior uptake, contrast, and extended imaging window made possible by copper-64’s longer half-life. Where 68Ga-DOTATATE demands rapid imaging (courtesy of gallium-68’s one-hour half-life), 64Cu-SARTATE offers a flexible 4 to 20-hour window – a practical boon for patients and clinicians alike.

It’s not just about imaging flexibility. The higher tumour-to-background ratio of 64Cu-SARTATE scans – particularly useful in liver lesions, where NETs often set up shop – makes lesion identification more accurate and visually intuitive. In one illustrated case, a 59-year-old participant’s 64Cu-SARTATE scans clearly outclassed the older tracer, revealing lesions hidden in the hepatic fog of gallium’s background uptake.

Safety-wise, 64Cu-SARTATE was well tolerated. Only seven participants reported treatment-related adverse events, all mild and resolving quickly. No serious adverse events were recorded.

So where to from here? Clarity plans to charge ahead with a registrational Phase III trial, under the watchful guidance of the US FDA. The company is also eyeing broader applications beyond NETs, such as breast and lung cancers – both known to express the SSTR2 receptor targeted by SARTATE.

The market potential is far from trivial. In the US alone, NET imaging accounts for roughly 100,000 scans annually, projected to hit 120,000 by 2029. Clarity believes the diagnostic market for 64Cu-SARTATE could eventually rival – or surpass – the prostate cancer imaging sector, where radiopharmaceuticals currently reign.

For now, investors may be taking notice of what Clarity calls “next-generation, patient-centric medicine.” In contrast to the “isotope-centric” limitations of gallium-based agents, copper-based diagnostics like SARTATE offer logistical ease, clinical flexibility, and improved performance – a trifecta that’s hard to ignore.

Assuming Phase III plays out as expected, Clarity may be poised to turn radiopharmaceutical diagnostics into a radiantly clear proposition.