Clinical-stage radiopharmaceutical company Clarity Pharmaceuticals (ASX:CU6) has added a new asset, 64/67Cu-SAR-trastuzumab, into its Targeted Copper Theranostic (TCT) portfolio.
The company said it has signed an agreement with EirGenix for the clinical development and future commercial supply of clinical-grade GMP trastuzumab biosimilar, EG12014. It said the supply enables the development of a radiolabelled product using its SAR Technology.
Trastuzumab is an antibody that targets HER2, expressed in many cancers, including lung, gastric and breast cancers.
Through a collaboration with the University of Melbourne, the trastuzumab antibody was combined with Clarity’s proprietary SAR chelator and radiolabelled with copper-64 (Cu-64 or 64Cu) for diagnostic imaging and copper-67 (Cu-67 or 67Cu), forming a radioimmunotherapy. 64Cu-SAR-trastuzumab targeted HER2- positive cancer cells to a very high level pre-clinically. 67Cu-SAR-trastuzumab was shown to significantly reduce the growth of HER2-expressing tumours in a dose-dependent manner, as well as to improve the survival of mice treated with the product.
Clarity’s executive chairperson, Dr Alan Taylor, said, “The antibody revolution over the last few decades has transformed the treatment of many diseases and has also led to the development of the antibody-drug conjugate (ADC) market. However, the application of antibodies in radiopharmaceuticals, despite many potential benefits of radiation compared to the cytotoxic payloads used in ADCs, has been limited with the current strategies being sub-optimal, particularly in comparison with peptides.
"At Clarity, we continue to strive for excellence when it comes to science and treatment outcomes, working to firstly open up a broad range of targeting technologies for radiopharmaceuticals in a safe and effective manner, and secondly, broaden the use of radiopharmaceuticals outside of prostate cancer when looking at large cancer indications.
“We have been investigating a number of antibody strategies for many years, including the use of whole antibodies, antibody fragments and antibody pre-targeting in combination with our SAR Technology to develop a new class of treatments when combined with antibodies in RIT. The 64/67Cu-SAR-trastuzumab product is a result of this R&D process.
“The pre-clinical results we generated so far are very exciting and highlight the potential benefit of 64/67Cu-SARtrastuzumab to image and treat patients with HER2-positive cancers. This is an area of high unmet need, as a considerable proportion of patients, most of whom are women, will relapse or develop resistance to standard treatments, and metastatic disease remains incurable."
EirGenix’s chairman and president, Dr. Liu, added, “We are very pleased to be working with Clarity on this important program to develop a novel treatment option for breast cancer patients. At EirGenix we believe that RIT using copper-67 is a promising avenue for the next generation of antibody therapies, and we are thrilled to be contributing to the development of this unique product.”