Clarity Pharmaceuticals has entered into a Master Services Agreement (MSA) and Clinical Manufacturing Agreement with Nucleus RadioPharma to support the development and manufacturing of 67Cu-SAR-bisPSMA for the ongoing phase 3 SECuRE trial (NCT04868604) in metastatic castration-resistant prostate cancer (mCRPC). The agreement, effective from November 8, 2024, spans an initial 36-month period, with final study completion anticipated in September 2026.
The SECuRE trial is a multi-center phase 1/2a study evaluating the safety and efficacy of 67Cu-SAR-bisPSMA in patients with mCRPC. The trial utilizes 64Cu-SAR-bisPSMA to visualize PSMA-expressing lesions, aiding in the selection of candidates for therapy with 67Cu-SAR-bisPSMA. Approximately 44 heavily pre-treated patients with mCRPC across the US and Australia have been enrolled in the phase 1/2a study.
Encouraging Early Data
Recent updates from Clarity Pharmaceuticals highlight encouraging safety and efficacy data from the SECuRE trial. Specifically, the third participant in cohort 4, which is the first to assess multi-dose treatment of 67Cu-SAR-bisPSMA at the highest dose level of 12 GBq, has completed the dose-limiting toxicity period. Preliminary data from the first three patients in cohort 4 showed no dose-limiting toxicities, aligning with results from previous cohorts. Most adverse events were mild or moderate, with many resolving or improving by the last assessment.
Efficacy data from these initial patients revealed prostate-specific antigen (PSA) reductions following two doses of 67Cu-SAR-bisPSMA, with the largest PSA decline reported at 95.7%. Based on these findings, the Safety Review Committee (SRC) recommended proceeding with dosing the final three patients in the cohort, all of whom have now been allocated. Pending a positive safety evaluation, the dose expansion phase of the trial will commence with 14 participants.
Addressing Unmet Needs in Prostate Cancer
"We continue to strengthen our manufacturing network, ensuring prostate cancer patients in need of novel radiopharmaceutical treatments can get access to what we believe is a best-in-class product, on time and on demand," said Clarity’s executive chairperson, Alan Taylor, PhD. "We have seen excellent data from the SECuRE trial and in case studies as part of the U.S. Food and Drug Administration (FDA) Expanded Access Program (EAP) with 67Cu-SAR-bisPSMA and look forward to progressing the development of this important therapy to address the large unmet need in prostate cancer care."
Patients enrolled in cohort 4 received multiple treatment cycles of 67Cu-SAR-bisPSMA (ranging from 2 to 4) at the 12 GBq dose level. Previous cohorts (1-3) received 67Cu-SAR-bisPSMA at ascending single-dose levels.
