Clarity Receives FDA IND Approval for Phase II SAR-Bombesin Imaging Trial for Prostate Cancer

Clarity Pharmaceuticals has received US FDA approval of its Investigational New Drug (IND) application to evaluate its SAR-Bombesin product as an imaging agent in prostate cancer patients that are Prostate-Specific Membrane Antigen (PSMA)-negative.

 “Receiving clearance from the FDA on the imaging trial with SAR-Bombesin is yet another significant milestone for Clarity,” said Clarity’s Executive Chairman, Dr Alan Taylor. “It shows our ability to develop cutting-edge theranostics from the lab, through preclinical studies and into clinical trials, with SAR-Bombesin being Clarity’s fourth IND across five products which are clear for investigation in the US.”

This IND gives Clarity clearance to proceed with a US-based Phase II⁶⁴Cu SAR-Bombesin Positron Emission Tomography (PET) imaging trial in participants with PSMA-negative biochemical recurrence (BCR) of prostate cancer following definitive therapy (such as surgery or radiation).

SABRE, which derives from “Copper-64 SAR-Bombesin in Biochemical REcurrence of Prostate Cancer trial”, is a multi-center, single arm, non-randomized, open-label trial in up to 50 PSMA-negative patients with known or suspected prostate cancer. The primary objectives of the trial are to investigate the safety and tolerability of⁶⁴Cu SAR-Bombesin, as well as its ability to correctly detect the recurrence of prostate cancer.

The SABRE trial builds upon the promising clinical data from the pilot trial assessment of⁶⁴Cu SAR-Bombesin in breast cancer led by Prof Louise Emmett of St Vincent’s Hospital Sydney. The data from this trial was recently presented at the prestigious American Society of Clinical Oncology (ASCO) 2022 Annual Meeting. The SABRE trial was developed in response to the strong demand for this product from clinicians with prostate cancer patients whose cancer was not visible with currently approved PSMA diagnostic agents or conventional imaging (such as CT and/or MRI). Their patients were successfully imaged with 64Cu SAR-Bombesin under a Special Access Scheme.

Published research has shown that approximately 20% of prostate cancers with BCR are PSMA-PET negative. These patients are therefore unlikely to respond to therapeutic PSMA-targeted products and currently have few treatment options available to them. Given the prostate cancer indication is one of the largest in oncology, there is a significant unmet medical need in this segment. The SAR-Bombesin product targets the Gastrin Releasing Peptide receptor (GRPr) found on prostate and many other cancers. As such, the product could offer valuable imaging and therapeutic options for not only PSMA negative patients, but also the large number of patients that have the target receptor on their cancers.

“We look forward to further progressing the development of SAR-Bombesin and hope it will provide a new and effective diagnostic option for prostate cancer patients. Building on the promising clinical and preclinical data acquired to date, we are also planning an IND submission for a theranostic trial in prostate cancer participants, using⁶⁷Cu SAR-Bombesin therapy paired with the imaging agent,⁶⁴Cu SAR-Bombesin. Combined with the clinical, environmental and logistical benefits enabled by the copper isotope pairing, SAR-Bombesin has potential to provide this large patient population with accurate and precise detection and treatment of prostate cancer. We anticipate the SABRE trial to commence shortly and the theranostic trial to commence in 2023,” Dr Taylor added.