Clarity Pharmaceuticals bags FDA fast track designation for prostate cancer candidate 67Cu-SAR-bisPSMA

Clarity Pharmaceuticals has achieved a major regulatory milestone with the United States Food and Drug Administration (FDA) granting Fast Track Designation to 67Cu-SAR-bisPSMA, a targeted radiopharmaceutical therapy designed for patients with prostate-specific membrane antigen (PSMA)-positive metastatic castration-resistant prostate cancer (mCRPC). The designation is expected to accelerate the development and regulatory review of this innovative treatment, which aims to enhance outcomes for patients who have previously undergone androgen receptor pathway inhibition (ARPI).

The latest designation adds to Clarity Pharmaceuticals’ growing pipeline of advanced radiopharmaceutical products. It follows two prior Fast Track Designations for its diagnostic agent, 64Cu-SAR-bisPSMA, which is being evaluated in two Phase III trials for its role in detecting prostate cancer metastasis and biochemical recurrence (BCR) following definitive therapy. These regulatory advancements highlight the potential of Clarity’s Targeted Copper Theranostic (TCT) platform in transforming the landscape of prostate cancer treatment from early detection to advanced-stage therapy.

What Does Fast Track Designation Mean for Clarity Pharmaceuticals?

The FDA’s Fast Track Designation is granted to therapies addressing serious medical conditions with high unmet needs. The program provides multiple advantages, including more frequent engagement with the FDA, rolling submission of regulatory data, and the potential for priority review once the drug application is submitted.

For 67Cu-SAR-bisPSMA, this means an expedited pathway to approval, reducing regulatory barriers that often slow the introduction of new radiopharmaceutical therapies. The streamlined process is expected to shorten the time required to bring this novel therapy to market, reinforcing Clarity Pharmaceuticals’ position as a key player in precision oncology.

How Does 67Cu-SAR-bisPSMA Work in Prostate Cancer Treatment?

SAR-bisPSMA utilizes Clarity Pharmaceuticals’ proprietary sarcophagine (SAR) technology, a cutting-edge chelator system that securely binds copper isotopes for both imaging and treatment. Unlike traditional radiopharmaceutical agents, SAR technology prevents copper leakage, ensuring higher precision in targeting cancer cells while reducing off-target radiation exposure.

The drug’s mechanism is based on a dual-ligand approach, which enhances its ability to bind to PSMA receptors expressed on prostate cancer cells. The compound is paired with copper-64 (64Cu) for imaging purposes and copper-67 (67Cu) for therapeutic applications, forming a comprehensive theranostic solution that allows for both diagnosis and treatment within the same platform.

What Do Early Clinical Trials Reveal About 67Cu-SAR-bisPSMA?

The FDA’s Fast Track Designation for 67Cu-SAR-bisPSMA was supported by early findings from the ongoing Phase I/IIa SECuRE trial (NCT04868604), which is assessing the drug’s safety, tolerability, and efficacy in patients with metastatic castration-resistant prostate cancer.

Preliminary results have demonstrated significant clinical benefits, particularly in reducing prostate-specific antigen (PSA) levels, a key biomarker of prostate cancer progression. The dose-escalation phase of the trial has been successfully completed, with no dose-limiting toxicities (DLTs) reported among participants.

Early efficacy data indicates that a single dose of 67Cu-SAR-bisPSMA has led to PSA reductions in over 73% of patients, despite many of them being heavily pre-treated with multiple prior therapies. In higher-dose cohorts, nearly 75% of participants experienced a PSA reduction of at least 35%, with some reporting tumor shrinkage of over 80% based on PSMA PET imaging.

One of the most remarkable responses was observed in a participant from cohort 4, who experienced a 98% decline in PSA levels following treatment with a 12 GBq multi-dose regimen. The patient had previously failed multiple lines of therapy, including androgen deprivation therapy (ADT), ARPI, and an investigational agent, yet still demonstrated a 60.6% reduction in tumor volume.

What Are the Next Steps for Clarity’s Clinical Trials?

Following the encouraging results from early trials, Clarity Pharmaceuticals is now expanding the SECuRE study to evaluate the potential benefits of combining 67Cu-SAR-bisPSMA with enzalutamide, an androgen receptor inhibitor widely used in prostate cancer treatment.

This decision aligns with recent findings from the Enza-p trial, which was presented at major medical conferences, including the European Society for Medical Oncology (ESMO) and the American Society of Clinical Oncology Genitourinary Cancers (ASCO GU) Symposium. The data suggested that targeting both androgen signaling and PSMA receptors simultaneously could enhance treatment outcomes in metastatic castration-resistant prostate cancer.

As part of this expansion, Clarity Pharmaceuticals has increased the number of participants in the cohort expansion phase from 14 to 24, with a subset of patients receiving combination therapy with enzalutamide. These amendments have been approved at multiple trial sites, and the updated protocol is expected to further strengthen the case for 67Cu-SAR-bisPSMA’s regulatory approval.

How Could 67Cu-SAR-bisPSMA Transform the Prostate Cancer Market?

With prostate cancer being one of the most prevalent cancers globally, there is a growing demand for more effective radiopharmaceutical therapy options. Clarity Pharmaceuticals is targeting the pre-chemotherapy treatment segment, which is estimated to be three times larger than the post-chemotherapy market. This strategic focus positions 67Cu-SAR-bisPSMA as a potential first-line radiopharmaceutical therapy for metastatic castration-resistant prostate cancer, addressing a critical gap in treatment availability.

Moreover, Clarity’s 64Cu/67Cu theranostic platform is uniquely positioned to resolve radiopharmaceutical supply chain challenges, which have hindered the adoption of similar therapies. By leveraging copper-based isotopes, the company aims to offer a scalable and sustainable alternative to existing PSMA-targeted radioligand therapies.

What Are Experts Saying About This Fast Track Designation?

Dr. Alan Taylor, Executive Chairperson of Clarity Pharmaceuticals, described the FDA’s decision as a testament to the company’s cutting-edge scientific approach. He emphasized that receiving three Fast Track Designations within a six-month period reflects the strength of the SAR-bisPSMA platform and its potential to redefine prostate cancer treatment.

According to Dr. Taylor, the company remains committed to working closely with the FDA to accelerate development timelines and bring 67Cu-SAR-bisPSMA to market as efficiently as possible. The next phase of the SECuRE trial will generate further data on combination therapy strategies, setting the stage for potential regulatory approval and commercialization.