SYDNEY, May 4, 2021 /PRNewswire/ -- Clarity Pharmaceuticals, a clinical stage radiopharmaceutical company focused on the treatment of serious disease, is pleased to announce that it has received a response from the U.S. Food and Drug Administration (FDA) on its Investigational New Drug (IND) application that the study for selection and treatment of Prostate-Specific Membrane Antigen (PSMA) positive prostate cancers using 64Cu-SAR-bisPSMA and 67Cu-SAR-bisPSMA may proceed.

The SECuRE trial (Systemic Cu theranostics in prostate cancer) is a Phase I/IIa study for identification and treatment of PSMA-expressing metastatic castrate resistant prostate cancer (mCRPC), which will be conducted in the U.S. (NCT04868604)[1]. It is a theranostic multi-centre, single arm, dose escalation study with a cohort expansion planned for up to 44 patients. The trial employs diagnostic Positron Emission Tomography imaging with 64Cu-SAR-bisPSMA for selection of patients suitable for therapy cycles with 67Cu-SAR-bis-PSMA.

Prostate cancer is the second most common cancer diagnosed in men globally and the fifth leading cause of death worldwide[2]. The American Cancer Society estimates in 2021 there will be 248,530 new cases of prostate cancer in the U.S. and around 34,130 deaths from the disease[3]. For metastatic prostate cancer, the 5-year relative survival rate is 30%, indicating a high unmet need for early detection and better treatment options for mCRPC. Annually, there are around ~34,000 men in the U.S. who are diagnosed with mCRCP[3], ~90% of whom have tumours which express PSMA[4].
Although there are some new therapeutic radiopharmaceutical agents for prostate cancer in late phase clinical trials, given the large patient population, product supply for therapeutic radiopharmaceuticals presents a constraint as they rely on the production of therapeutic isotopes from a small number of nuclear reactors, with reactor shutdowns often causing isotope shortages around the globe.

Clarity's SAR-bisPSMA product utilises two isotopes of copper, which do not have the same constraints:

The therapeutic product utilises copper-67, which is being produced domestically in the USA on electron accelerators, avoiding the issues commonly associated with the production of isotopes on nuclear reactors.
The diagnostic product utilises copper-64, which is regularly produced in significant volumes on cyclotrons in the U.S., and has a half-life of 12.7 hours, avoiding the short half-life issues of other diagnostic isotopes.

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