Clinical-stage radiopharmaceutical company Clarity Pharmaceuticals (ASX: CU6) has announced the dosing of the first patient in its theranostic 64Cu/67Cu SAR-Bombesin Phase I/II trial in metastatic castrate resistant prostate cancer (mCRPC).
The company reports no issues were observed during the administration of 6GBq of 67Cu SAR-Bombesin and the participant continues to be followed for further safety and efficacy assessments as per protocol.
COMBAT, which derives from Copper-67 SAR-Bombesin in metastatic castrate resistant prostate cancer (NCT05633160) is a dose escalation and cohort expansion trial for up to 38 participants.
64Cu SAR-Bombesin is used to visualise gastrin-releasing peptide receptor (GRPr)-expressing lesions and select candidates for subsequent 67Cu SAR-Bombesin therapy. The aim for the trial is to determine the safety and efficacy of 67Cu SAR-Bombesin in participants with GRPr expressing mCRPC who are ineligible for therapy with 177Lu PSMA-617.
These patients are unlikely to benefit from prostate-specific membrane antigen (PSMA)-targeted agents and represent a significant unmet need for both imaging and therapy. Doses of up to 14GBq of 67Cu SAR-Bombesin, in up to four cycles, are planned to be investigated in this trial (pending safety reviews).
SAR-Bombesin has already resulted in improvements to the management of prostate cancer for patients with PSMA-negative or low PSMA expressing lesions through diagnostic trials and we hope to confirm its safety and efficacy in this theranostic trial,” Clarity’s Executive Chairperson, Dr Alan Taylor, said.
“We look forward to progressing the COMBAT trial and building on the compelling data from our preclinical and clinical studies to date. Combined with the logistical and manufacturing benefits of Targeted Copper Theranostics and with commercial quantities of the 67Cu radioisotope now being routinely produced domestically in the US, we see a clear path to bringing SAR-Bombesin and SAR-bisPSMA to the prostate cancer patient population in need of novel treatments.”
SAR-Bombesin is a highly targeted pan-cancer radiopharmaceutical with broad cancer application. It targets the gastrin- releasing peptide receptor (GRPr) present on cells of a range of cancers, including but not limited to prostate, breast and ovarian cancers. GRPr is found in up to 100% of prostate cancers, including prostate cancers that don’t express PSMA (PSMA-negative).
The product utilises Clarity’s proprietary sarcophagine (SAR) technology that securely holds copper isotopes inside a cage-like structure, called a chelator. Unlike other commercially available chelators, the SAR technology prevents copper leakage into the body. SAR-Bombesin is a Targeted Copper Theranostic (TCT) that can be used with isotopes of copper-64 (Cu-64 or 64Cu) for imaging and copper-67 (Cu-67 or 67Cu) for therapy.
64Cu SAR-Bombesin and 67Cu SAR-Bombesin are unregistered products. Individual results may not represent the overall safety and efficacy of the products. The data outlined in this announcement has not been assessed by health authorities such as the US Food and Drug Administration (FDA).
