FDA authorizes trial of novel PSMA theranostics in mCRPC

The FDA has authorized the launch of the phase 1/2a SECURE trial exploring 2 novel PSMA theranostic products in patients with metastatic castration-resistant prostate cancer (mCRPC), according to Clarity Pharmaceuticals, the company developing the investigational agents.¹

The open-label, single-arm, dose-escalation SECURE trial (NCT04868604) is specifically exploring the PSMA PET imaging product ⁶⁴Cu-SAR-bisPSMA and the PSMA targeted therapy ⁶⁷Cu-SAR-bisPSMA.² The basic design of the trial is that ⁶⁴Cu-SAR-bisPSMA will be used for the selection of appropriate patients to receive treatment with ⁶⁷Cu-SAR-bis-PSMA. The study aims to enroll 44 patients at multiple locations in the United States.

To enroll on the trial, patients must have mCRPC that has progressed despite being treated with androgen-deprivation therapy and at least 1 second-generation androgen receptor pathway inhibitor, such as abiraterone acetate (Zytiga) or enzalutamide (Xtandi). Patients are required to have an ECOG performance status of 0 to 2, and a castrate level of serum/plasma testosterone (<50 ng/dL or <1.7 nmol/L). Individuals with brain metastases are not eligible to enroll.

"The FDA response suggests not only the importance of developing novel treatments for men with late-stage prostate cancer, whose prognosis is currently very poor, but also validates Clarity's copper pairing paradigm and the centralized manufacturing concept, which differentiates it from the competitor products and enables product supply to the levels suitable for use in large patient indications," Dr Alan Taylor, executive chairman of Clarity, stated in a press release.

"We are very excited to commence the SECURE trial in mCRPC patients and have engaged a world class group of key opinion leaders in the prostate cancer space to support the development of ^64/67Cu SAR-bisPSMA. Clarity's Global Clinical Development Group has unrivalled experience in the commercialization of the only currently approved radiotherapeutic for prostate cancer. The FDA response is a crucial milestone in the development of SAR-bisPSMA theranostics and we are looking forward to progressing this trial at some of the leading cancer centers in the United States as part of our ultimate goal of developing better treatments for children and adults with cancer," added Taylor.

PSMA-PET imaging has emerged as a new frontier in prostate cancer diagnosis and treatment. In December 2020, the FDA approved Gallium 68 PSMA-11 as the first product for PET imaging of PSMA-positive lesions in men with prostate cancer. Other PSMA products, such as the PSMA-targeted radiopharmaceutical 177Lu-PSMA-617, are now rapidly moving through the pipeline in prostate cancer.

For additional information on the emergence of PSMA products in prostate cancer, watch our exclusive interview on PSMA with Evan Y. Yu, MD, a professor in the Department of Medicine, Division of Oncology, University of Washington and Fred Hutchinson Cancer Research Center. In the interview, Yu discusses the background of PSMA-PET imaging, current and emerging PSMA imaging tools/therapeutics, and the future of the novel technique in prostate cancer.

References

1. Clarity receives US FDA clearance of IND Application for its next-generation PSMA theranostic products. Published online May 4, 2021. Accessed May 5, 2021. https://prn.to/2RuDy6I.

2. NIH ClinicalTrials.gov. 64Cu-SAR-bisPSMA and 67Cu-SAR-bisPSMA for Identification and Treatment of PSMA-expressing Metastatic Castrate Resistant Prostate Cancer (SECURE). Last update May 3, 2021. Accessed May 5, 2021. https://clinicaltrials.gov/ct2/show/NCT04868604