Blue Earth Diagnostics Announces Reader Reproducibility Results from Phase 3 SPOTLIGHT Trial of Investigational PET Imaging Agent 18F-rhPSMA-7.3 in Biochemical Recurrence of Prostate Cancer

− Oral presentation highlighted at 2022 Society of Nuclear Medicine and Molecular Imaging (SNMMI) Annual Meeting –

Reno, Nevada (UroToday.com) -- Blue Earth Diagnostics, a Bracco company and recognized leader in the development and commercialization of innovative PET radiopharmaceuticals, announced inter- and intra-reader reproducibility results from its Phase 3 SPOTLIGHT trial of 18F-rhPSMA-7.3 in recurrent prostate cancer. Results for the inter-reader agreement showed that agreement was high across all readers. The inter-reader agreement for 18F-rhPSMA-7.3 PET/CT was more than 75% overall and greatest for the pelvic lymph node region, with more than 87% concordance. Intra-reader agreement was more than 85% overall. 18F-rhPSMA-7.3 is an investigational high affinity radiohybrid (rh) Prostate-Specific Membrane Antigen-targeted PET imaging agent. The results were reported in an oral presentation at the 2022 Society of Nuclear Medicine and Molecular Imaging (SNMMI) Annual Meeting.


“Biochemically recurrent prostate cancer can be locally recurrent disease, metastatic disease, or both. Therefore, optimal assessment of the extent and location of recurrent prostate cancer is critical for clinical decision-making by physicians and patients,” said Phillip Kuo, MD, Ph.D., Departments of Medical Imaging, Medicine, and Biomedical Engineering, University of Arizona, Tucson, Ariz. and Invicro, Needham, Mass., on behalf of the SPOTLIGHT study group. “Unfortunately, recurrence of prostate cancer is common. Conventional imaging, such as CT and bone scintigraphy, is often negative particularly when PSA is still low, so the demonstrated performance of PSMA-PET imaging fits an important unmet need. But no matter how good the radiotracer or scanner, reliable and consistent interpretation of PET imaging is foundational and has the potential to substantially impact patient care. These findings from the SPOTLIGHT study showed high inter-reader and intra-reader agreement for interpretation of 18F-rhPSMA-7.3 PET/CT scans in the setting of biochemical recurrence. Such high reproducibility, particularly for extra-prostatic regions, is clinically valuable, due to the potential of these findings to influence patient management.”

“We are pleased to present these reader interpretation results from the Phase 3 SPOTLIGHT trial at SNMMI’s 2022 Annual Meeting, as they will be a critical element of a New Drug Application with the U.S. Food and Drug Administration (FDA) for 18F-rhPSMA-7.3 PET imaging,” said David E. Gauden, D.Phil., Chief Executive Officer of Blue Earth Diagnostics. “In designing the image interpretation training to be used for the 18F-rhPSMA-7.3 Phase 3 program, we drew upon Blue Earth Diagnostics’ expertise and experience in designing PET image interpretation programs and training for commercialized Axumin® (fluciclovine F 18). We selected 18F as the isotope of choice for PET imaging with rhPSMA in consideration of its spatial resolution and resulting high quality of PET images, and its physical half-life which greatly facilitates ease of large-scale manufacturing and distribution for broad-based patient access. 18F-rhPSMA-7.3 represents a new class of high affinity PSMA-targeted PET radiopharmaceuticals. Early studies of 18F‐rhPSMA‐7.3 showed a binding affinity for PSMA, together with biodistribution data suggesting the potential for low bladder activity.”
The findings presented at SNMMI discussed inter- and intra-reader agreement for the interpretation of 18F-rhPSMA-7.3 scans. Overall agreement between all three blinded readers who received identical training was assessed and repeated for the regions of the prostate/prostate bed, pelvic lymph nodes, and other (extra-pelvic) sites (lymph nodes outside pelvis, soft tissue/parenchyma, and bones). Results showed that agreement was high across all readers. The inter-reader agreement for 18F-rhPSMA-7.3 PET/CT was more than 75% overall and greatest for the pelvic lymph node region, with more than 87% concordance. Intra-reader agreement was more than 85% overall. Reproducibility was lower for the prostate/prostate bed than other regions; however, the high reproducibility for extra-prostatic regions is clinically valuable due to the potential of these findings to influence patient management.

The SPOTLIGHT trial (NCT04186845) is a Phase 3, multi-center, single-arm imaging study conducted in the United States and Europe to evaluate the safety and diagnostic performance of 18F-rhPSMA-7.3 PET imaging in men with suspected prostate cancer recurrence based on elevated PSA following prior therapy. Key results for 18F-rhPSMA-7.3 PET were previously presented at ASCO GU in February 2022,1 with additional results announced at AUA in April 2022.2

The findings were discussed in an oral presentation at SNMMI 2022 on June 14, 2022, “Inter- and intra-reader reproducibility of 18F-rhPSMA-7.3 PET image interpretation in patients with suspected prostate cancer recurrence: Results from a phase 3, prospective, multicenter study (SPOTLIGHT), by Phillip Kuo, MD, Ph.D., Departments of Medical Imaging, Medicine, and Biomedical Engineering, University of Arizona, Tucson, Ariz. and Invicro, Boston, Mass., on behalf of the SPOTLIGHT study group. Full session details and the abstract are available in the SNMMI online program.

1DM Schuster, SPOTLIGHT Study Group. J. Clin. Onc. 2022; 40 (6_suppl):9-9.
2MT Fleming, SPOTLIGHT Study Group, J. Urol. 2022, 207 (5_suppl):31047.

Source: "News | Blue Earth Diagnostics". 2022. Blueearthdiagnostics.Com. https://www.blueearthdiagnostics.com/news.