CLARIFY trial reaches enrollment target for 64Cu-SAR-bisPSMA in prostate cancer

Enrollment has reached the planned 383 participants in the phase 3 CLARIFY trial evaluating ⁶⁴Cu-SAR-bisPSMA PET/CT for detecting pelvic lymph node metastases in patients with high-risk prostate cancer prior to radical prostatectomy, Clarity Pharmaceuticals announced.¹

The study is designed to assess whether the investigational imaging agent can accurately identify regional lymph node involvement using both same-day and next-day imaging, with histopathology serving as the reference standard. According to the company, topline results are anticipated in the first half of 2027.

“This milestone is a significant achievement from our team and collaborators as we progress our [optimized] ⁶⁴Cu-SAR-bisPSMA product towards trial completion and subsequent US FDA New Drug Application (NDA) submission,” said Alan Taylor, executive chairperson of Clarity Pharmaceuticals, in the company’s news release.¹

Trial design

CLARIFY (NCT06056830) is a prospective, multicenter, single-arm phase 3 diagnostic performance study being conducted in the US and Australia. The trial enrolled patients with untreated, histologically confirmed prostate cancer with high-risk features who had elected to undergo radical prostatectomy with pelvic lymph node dissection.

The primary objective is to evaluate the sensitivity and specificity of ⁶⁴Cu-SAR-bisPSMA PET/CT for detecting prostate cancer in pelvic lymph nodes, using histopathologic examination of surgically removed lymph nodes as the reference standard. The study evaluates diagnostic performance at 2 imaging time points: 1 to 4 hours after administration on day 1 (same-day imaging) and approximately 24 hours after administration on day 2 (next-day imaging).

Taylor noted, "What is most important about the CLARIFY trial is that this study is the first to determine the sensitivity and specificity of our SAR-bisPSMA product, based on the appropriate assessment of true positive, true negative, false positive and false negative lesions that can only be determined accurately using histopathology specimens (in this case, pelvic lymph nodes that are surgically removed during prostatectomy). [Utilizing] similar principles in study design to those previously used by other PSMA imaging agents on the market for their respective registrational Phase 3 studies, CLARIFY will provide sensitivity and specificity estimates for same-day and next-day imaging, as well as have direct comparative data to SOC PSMA imaging where SOC PET was undertaken.”

Topline results from the trial are expected in the first half of 2027. The study is intended to support an application to the FDA seeking approval of ⁶⁴Cu-SAR-bisPSMA as a prostate cancer imaging agent.

Earlier clinical findings

The development of ⁶⁴Cu-SAR-bisPSMA builds on findings from PROPELLER (NCT04839367), an early-phase study that evaluated the agent in 30 patients with prostate cancer before prostatectomy. According to Clarity the study suggested greater lesion detection and higher tracer uptake and contrast with ⁶⁴Cu-SAR-bisPSMA compared with ⁶⁸Ga-PSMA-11.²

The company also cited findings from the COBRA and Co-PSMA studies, which evaluated ⁶⁴Cu-SAR-bisPSMA in patients with biochemical recurrence of prostate cancer. These studies investigated imaging at different intervals after administration, including approximately 24 hours after injection. According to the company, the results indicated that next-day imaging may provide incremental benefits in the pre-prostatectomy setting.

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REFERENCES

1. Registrational phase III CLARIFY trial: Target number of participants achieved. News release. Clarity Pharmaceuticals. October 27, 2026. Accessed October 28, 2026. https://www.claritypharmaceuticals.com/news/clarify_recruitment/

2. Lengyelova E, Wong V, Lenzo N, et al. 64Cu-SAR-bisPSMA (PROPELLER) positron emission tomography (PET) imaging in patients with confirmed prostate cancer. J Clin Oncol. 2023;41(5039). doi:10.1200/JCO.2023.41.16_suppl.5039