Clarity Pharmaceuticals, an Australia-based clinical-stage radiopharmaceutical company, has successfully recruited and treated its first patient in the Phase I/II theranostic trial evaluating ⁶⁴Cu/⁶⁷Cu SAR-bisPSMA theranostic product in patients with metastatic, castration-resistant prostate cancer (mCRPC). SAR-bisPSMA is a next-generation platform that uses inexpensive copper-67 radioisotopes. As a result, it may prove to be cost effective, giving it an advantage over other theranostics, says GlobalData, a leading data and analytics company.

Theranostics is a novel approach that combines therapeutics with diagnostics has opened new avenues in the simultaneous diagnosis and treatment of prostate cancer patients. These agents have a great potential to be effective drugs, cancer cell marker detectors and imaging agents in near future. Theranostics utilizes a diagnostic test to specifically detect cancer and target specific drug delivery to treat the tumour.

GlobalData’s Pharmaceutical Intelligence Center reveals that prostate cancer was the third most common cause of cancer deaths in Australia in 2020. The number of males living with prostate cancer in Australia (diagnosed in the past five years) is estimated to reach 70,923 in 2022.  Currently, there are about 22 marketed drugs in Australia for the cancer and a majority of them target the androgen receptor (AR) signaling pathway.

Dr. Pavan Sunkireddy, Pharma Analyst at GlobalData, comments: “The adoption of screening tests that allow the early detection and treatment of the tumor will be key in controlling the death rates from prostate cancer. Today, the most common diagnostic test for the cancer is the measurement of prostate-specific antigen (PSA) level. Though there are few controversies around this test, no other biomarker test has provided proper evidence to be able to replace the PSA test. Furthermore, the most important concern in the treatment of prostate cancer is the development of cross-resistance to AR-targeted therapies.”

Taking into account all the concerns over the prostate cancer detection and treatment, it would be logical to hope that next-generation innovative approaches would target prostate-specific membrane antigen (PSMA), one of the most specific cell surface markers for prostate cancer. Here, theranostics could be a great avenue to explore, as they offer a wide range of advantages like intracellular diagnosis and in vivo biodistribution, advanced therapy, and therapeutic monitoring following the treatment.

GlobalData’s Pharmaceutical Intelligence Center suggests that most of the theranostics from other companies are still in the early development stage, with two candidates in Phase I and three candidates in the preclinical stage.

Dr Sunkireddy concludes: “The preclinical and preliminary clinical data suggests the potential therapeutic activity of the tailored PSMA agent, but more data is required to draw any concrete conclusions on Clarity’s SAR-bisPSMA theranostic.”