SAR Technology platform

Clarity’s proprietary SAR Technology platform employs a superior chelator (or cage) for copper and can be used to develop next-generation products for the diagnosis and treatment of a wide range of cancers.

 

SAR Technology Platform

At the heart of Clarity’s theranostic SAR Technology platform is a bifunctional cage called a “chelator” that holds copper isotopes securely within and prevents their leakage into the body. This highly specific and highly stable cage is linked to a targeting molecule, which finds and binds tumour-specific receptors on cancer cells. Once the targeting molecule has found the tumour, the radioisotope can act in that location, either emitting radiation to be picked up by an imaging device (diagnostic radioisotope) or by destroying the cancer cells (therapeutic radioisotope).

Enabled by its proprietary technology, Clarity uses the “perfect pairing” of copper isotopes, copper-64 (Cu-64 or 64Cu) for diagnosis and copper-67 (Cu-67 or 67Cu) for therapy.

Clarity’s proprietary SAR Technology can be used to develop a range of theranostic radiopharmaceutical products that target different types of cancer by combining it with different targeting molecules.

High accuracy and high precision

The two key clinical benefits of using copper isotopes are that they provide high accuracy and high precision in diagnosing and treating cancer.

High accuracy is achieved by only selecting those patients for therapy who show product uptake in the tumours when imaging with a PET scan during the diagnostic stage, an indicator that the product targets the cancer and not healthy tissues, thereby maximising the probability of treatment success.

High precision is achieved by using the same targeting molecule with the same chemical element inside the chelator (a different isotope of copper), ensuring both the diagnostic and therapeutic products have identical targeting in vivo.

Superior copper cage

The “perfect pairing” of copper-64 (64Cu) and copper-67 (67Cu) isotopes for diagnosis and therapy has been discussed in scientific literature for approximately 25 years. The pairing is well suited for theranostics due to the unique physical characteristics of each isotope of copper as well as having the “ideal theranostic pair”, meaning the same product and same element are used for both diagnosis and therapy.

Historically, the utilisation of copper radioisotopes has been hampered as there were no suitable cages (chelators) that would hold the isotopes inside securely. Earlier attempts with other cages have resulted in the isotopes of copper being released from the cage once injected into the body and then metabolised in the liver, limiting their diagnostic potential and being unsuitable for therapeutic applications.

Clarity seeks to address this issue with its sarcophagine chelator and holds a large IP portfolio on the SAR Technology platform, enabling its commercial exploitation, whereas most other chelators remain unpatented.

Comparison of 64Cu SARTATE and 64Cu DOTATATE

Clarity’s 64Cu SARTATE

Hicks et al. J Nucl Med 2019; 60:777-785

64Cu DOTATATE

Pfeifer et al. J Nucl Med 2012; 53:1207-15

These images highlight the improvement in clinical outcomes that Clarity’s SAR Technology brings. Free 64Cu leaked from the chelators usually accumulates in the liver, presenting background radioactivity on diagnostic scans. The images of 64Cu SARTATE™ (image on the left) highlight that there is a decrease in detected radioactivity in the liver over time, which is indicative that there is minimal free 64Cu in the body as a result of chelator leakage, meaning that there is minimal copper leaking from the product. In comparison, images with 64Cu DOTATATE (image on the right), which employs a chelator called DOTA, show that there is a constant background in the liver, indicative of the presence of free 64Cu in the liver, meaning there is leakage from the DOTA chelator.

As a result, Clarity’s chelator technology allows PET images to be collected over a wide range of timepoints and, importantly, permits the use of 67Cu-based products for therapy. Utilising the patented SAR technology, Clarity is running a number of clinical trials in a range of cancer types.

Details of our current program can be found in the Pipeline section of the website.

Discovery Program

Clarity’s SAR Technology platform can be used in conjunction with any number of cancer targeting molecules to create new radiopharmaceutical products, which are developed in Clarity’s discovery program.

Clarity has a number of R&D projects in its Discovery Program, including:

  • New pipeline products; and
  • Second generation technology.

In December 2024, Clarity announced the development of a new preclinical stage asset called 64/67Cu-SAR-bisFAP, a pan-cancer Targeted Copper Theranostic.

  • 64/67Cu-SAR-bisFAP is a proprietary fibroblast activation protein (FAP)-targeted radiopharmaceutical product that can be used with the perfect pairing of copper isotopes for the diagnosis and treatment of cancer.
  • The product has shown strong tumour targeting, retention and pharmacokinetic data in pre-clinical models.
  • FAP is expressed widely across a range of malignancies, opening a very large pan-cancer opportunity for both imaging and treatment of various cancers.

 

In February 2025, Clarity announced the development of a new preclinical stage asset called 64/67Cu-SAR-Trastuzumab.

  • Combining the well-established trastuzumab antibody with Clarity’s proprietary SAR Technology enables the development of a copper-67 (Cu-67) based radioimmunotherapy (RIT) for HER2-positive breast cancer patients.
  • It is estimated that 316,950 women will be diagnosed with invasive breast cancer in 2025 in the US, with 42,170 dying from the disease1.
  • Human epidermal growth factor receptor 2 (HER2) is expressed in up to 20% of breast cancers and is associated with a more aggressive type of tumour and poor prognosis2.
  • Pre-clinical evidence shows dose-response reduction in tumour size and prolonged survival using 67Cu-SAR-trastuzumab compared to trastuzumab alone in a HER2-positive tumour mouse model3.
  • To secure supply of clinical-grade Good Manufacturing Practice (GMP) trastuzumab, Clarity signed a Supply Agreement with EirGenix, Inc. in February 2025.

 

1Siegel et al. Cancer statistics, 2025. CA Cancer J Clin. 2025.

2Exman et al. HER2-positive metastatic breast cancer: a comprehensive review. Clin Adv Hematol Oncol. 2021.

3Rudd et al. Potential theranostics of breast cancer with copper-64/67 sarcophagine-trastuzumab. Chem Sci. 2025.

 

Clarity continues to expand its pipeline with a range of Discovery programs ongoing. The majority of the Discovery work is done in collaboration with Clarity’s academic partners and external commercial service providers. The funding of the Discovery research is partially supported by grants and the Australian R&D Tax Incentive.