FDA Accepts NDA for 18F-rhPSMA-7.3 as Diagnostic Imaging Tool in Prostate Cancer

The FDA has accepted for review a new drug application (NDA) for ¹⁸F-rhPSMA-7.3, an investigational radiohybrid PSMA-targeted PET imaging agent for diagnostic imaging of prostate cancer, according to an announcement from Blue Earth Diagnostics.¹

“This event marks a significant milestone in advancing our robust prostate cancer portfolio, and we are very pleased that the FDA has accepted our NDA submission for the use of ¹⁸F-rhPSMA-7.3 PET imaging in prostate cancer patients,” David E. Gauden, DPhil, chief executive officer of Blue Earth Diagnostics, said in a press release. “We look forward to working with the Agency throughout the review process, with the goal of having an approved product that is widely available and accessible across the United States. Subject to FDA approval, we believe that ¹⁸F-rhPSMA-7.3 PET imaging may be clinically useful in the management of men affected by prostate cancer across the care continuum.”

The NDA is supported by data from a phase 1 study and the phase 3 LIGHTHOUSE (NCT04186819) and SPOTLIGHT (NCT04186845) trials. LIGHTHOUSE evaluated the safety and diagnostic performance of ¹⁸F-rhPSMA-7.3 PET in 356 patients with newly diagnosed prostate cancer. Preliminary results from the study will be presented at an upcoming medical meeting.

In SPOTLIGHT, investigators evaluated ¹⁸F-rhPSMA-7.3 in 391 men with suspected prostate cancer recurrence based on elevated prostate specific antigen (PSA) level. Updated data presented at the 2022 AUA Annual Meeting demonstrated that PET/CT scans conducted with ¹⁸F-rhPSMA-7.3 led to more frequent post-scan disease upstaging compared with baseline conventional imaging in patients with prostate cancer recurrence.^2,3

The study enrolled male patients who were at least 18 years of age and had received prior curative intent treatment for localized prostate cancer. Patients were required to have an elevated PSA that could indicate biochemical recurrence and be eligible for salvage therapy.

¹⁸F-rhPSMA-7.3 was administered at a dose of 296 MBq/8 mCi, and patients underwent PET/CT scans 50 to 70 minutes after injection. Scans were subsequently evaluated by 3 blinded central readers. The Standard of Truth was histopathology or confirmatory conventional imaging. Investigators performed biopsies within 60 days following PET scans and confirmatory imaging within 90 days.

Among 250 of 366 men in the efficacy analysis population who had negative baseline conventional imaging, ¹⁸F-rhPSMA-7.3 showed a correct detection rate of 45% to 47%.

“Prostate cancer is a leading cause of male cancer-related death worldwide, and accurate localization and staging of the disease is critical in establishing optimal medical management strategies,” Eugene Teoh, MBBS, MRCP, FRCR, DPhil, chief medical officer of Blue Earth Diagnostics, said. “We believe that the performance of ¹⁸F-rhPSMA-7.3, its high PSMA binding affinity and potential for low bladder activity, will make it a valuable diagnostic tool that is radiolabeled with ¹⁸F for high image quality and readily available patient access.”

References

1. Blue Earth Diagnostics announces FDA acceptance of new drug application for 18F-rhPSMA-7.3, a radiohybrid prostate-specific membrane antigen-targeted PET imaging agent for prostate cancer. News release. Blue Earth Diagnostics. September 27, 2022. Accessed September 29, 2022. https://bwnews.pr/3SmR2M9
2. Fleming MT. Impact of 18F-rhPSMA-7.3 PET on upstaging of patients with prostate cancer recurrence: results from the prospective, phase 3, multicenter, SPOTLIGHT study. Presented at: 2022 AUA Annual Meeting; May 13-16, 2022; New Orleans, LA. Abstract PLLBA-02.
3. Blue Earth Diagnostics announces additional results from phase 3 SPOTLIGHT trial of investigational PET imaging agent 18F-rhPSMA-7.3 in biochemical recurrence of prostate cancer. News release. Blue Earth Diagnostics. May 13, 2022. Accessed September 29, 2022. https://bwnews.pr/3wu1Cr9