Flotufolastat F 18 shows promising diagnostic performance in Black men with prostate cancer

Flotufolastat F 18 (US trade name, Posluma) demonstrated promising diagnostic performance in African American men with recurrent prostate cancer, according to a post hoc analysis of the phase 3 SPOTLIGHT trial (NCT04186845).¹

In total, the SPOTLIGHT trial enrolled 366 patients with recurrent prostate cancer, 61 of which were African American.

Flotufolastat F 18 received FDA approval in May 2023 for PET imaging of prostate-specific membrane antigen (PSMA)-positive lesions in patients with prostate cancer with suspected metastasis who are candidates for initial definitive therapy or who have suspected recurrence based on an elevated serum prostate-specific antigen (PSA) level.

“Beyond validating the diagnostic performance of POSLUMA in African American men, findings from the SPOTLIGHT study provide useful considerations for planning future clinical trials, to facilitate patient enrollment and achieve clinical trial diversity,” said Marco Campione, CEO of Blue Earth Diagnostics, in a news release on the findings.² “The results achieved in African American men were derived from clinical sites across the United States, and further support the broad applicability of POSLUMA for its indicated use across the US population as a whole.”

Overall, 17% (61/366) of men included in the SPOTLIGHT trial were African American. According to the authors, this is significantly higher than the proportion of African American patients typically seen in other types of oncology clinical trials, with a reported rate of 8.5%. The 17% rate observed in the SPOTLIGHT trial is also representative of the US population, in which approximately 14% of people are African American.

Data from the post-hoc analysis showed a high patient-level detection rate for flotufolastat F 18 in African American patients, with 93% having a positive scan. The detection rate increased from 67% in African American patients with a PSA less than 0.5 ng/mL to 100% among those with a PSA of 10 ng/mL or higher. Among all other participants in the study, the detection rate with flotufolastat F 18 was 87%.

Among patients who underwent a prostatectomy, the detection rates were similar between all ethnic groups. In patients with intact prostates, a higher detection rate was observed for African American men vs all other patients.

Further, the verified detection rate (VDR) among African American patients was 64%, vs 55% among all other patients. The positive predictive value (PPV) was 68% among African American patients and 64% among all other patients.

“Prostate cancer is the most commonly diagnosed cancer among African American men, who are twice more likely to die from the disease than White men. It is encouraging that African American enrollment in the SPOTLIGHT trial closely aligns with their 14% representation of the US population, because results from oncology trials with low diversity populations are less useful for clinical decision-making and can contribute to racial disparities in cancer outcomes,” said lead author Soroush Rais-Bahrami, MD, MBA, in the news release.² Rais-Bahrami is a professor of urology and radiology and the interim chair of urology at the University of Alabama at Birmingham Heersink School of Medicine in Birmingham, Alabama.

In total, the SPOTLIGHT trial enrolled 366 patients with recurrent prostate cancer, 61 of which were African American and were included in the current post-hoc analysis. All patients in the SPOTLIGHT trial underwent PET/CT 50 to 70 minutes following intravenous administration of 296 MBq of flotufolastat F 18.

For the study, standard of truth verification for VDR and PPV was established with histopathology or correlative imaging. According to the authors, standard-of-truth verified VDR is equivalent to detection rate x PPV.

Overall, the authors concluded, “The data evaluated in this study help to demonstrate the broad applicability of newly approved 18F-flotufolastat to the US population as a whole.”¹

References

1. Rais-Bahrami S, Fleming M, Gartrell B, et al. 18F-Flotufolastat positron emission tomography in African American patients with suspected prostate cancer recurrence: Findings from the phase 3 SPOTLIGHT study. Advances in Radiation Oncology. doi:10.1016/j.adro.2024.101571

2. Blue Earth Diagnostics, a Bracco Company, announces results evaluating diagnostic performance of POSLUMA (Flotufolastat F 18) and clinical trial enrollment in African American men with prostate cancer. News release. Blue Earth Diagnostics. Published online and accessed July 30, 2024. https://www.businesswire.com/news/home/20240730333904/en/Blue-Earth-Diagnostics-a-Bracco-Company-Announces-Results-Evaluating-Diagnostic-Performance-of-POSLUMA%C2%AE-Flotufolastat-F-18-and-Clinical-Trial-Enrollment-in-African-American-Men-with-Prostate-Cancer