Blood-based test shows promise in prostate cancer risk stratification

Data published in the Journal of Urology demonstrate the ability of a blood-based immunocyte transcriptomic signature to risk stratify patients with prostate cancer who are being considered for active surveillance.¹

According to Immunis.AI, the team plans to commercialize the test across the US and Europe.

“One of the big challenges in prostate cancer management is distinguishing those patients with early prostate cancer who are appropriate for active surveillance from those who need to be aggressively treated. The novel approach published by Immunis.AI utilizes the RNA signature created by the immune system’s response to cancer. The potential to better select patients would mark a significant advance in prostate cancer active surveillance,” said senior author Philip W. Kantoff, MD, in a news release on the findings.² Kantoff is an advisor to Immunis.AI and the CEO and co-founder of Convergent Therapeutics.

Results from the study showed that the model developed using an immunocyte transcriptomic profile based on 2 cell types with prostate-specific antigen (PSA) density and age performed the best in the active surveillance setting, with an area under the curve (AUC) of 0.73 (95% CI, 0.69-0.77). The developed model significantly outperformed PSA density as a biomarker (P < .001), which has an AUC of 0.69 (95% CI, 0.65-0.73). The model continued to outperform PSA density even when combined with age (AUC, 0.70; 95% CI, 0.66-0.74; P = .006).

Further, the model showed a significantly greater AUC compared with the Prostate Cancer Prevention Trial risk calculator, which demonstrated an AUC of 0.69 (95% CI, 0.65-0.73; P = .035).

The current model’s individualized patient risk scores also demonstrated a negative predictive value (NPV) of 90%, representing those at a 2.5-fold decreased risk of occult clinically significant prostate cancer, and a positive predictive value (PPV) of 50%, representing those with at least a 2.0-fold increased risk. The clinical-only model of age and PSA density resulted in a NPV of 88% and a PPV of 46%.

“The test is designed to non-invasively identify the presence of aggressive cancer in men already diagnosed with prostate cancer who are on or are considering starting active surveillance,” added co-author Kirk J. Wojno, MD, chief medical officer of Immunis.AI, in the news release.² “When used to aid in decisions concerning active surveillance of prostate cancer, our test has the potential to replace periodic invasive active surveillance procedures, including prostate tissue biopsies, with a simple blood test.”

In total, the study included 1017 patients in the training cohort and 1198 patients in the validation cohort who had risk profiles that warranted prostate biopsy, as determined by their physician. Blood samples from each patient were drawn coincident to their prostate biopsy, and immune cells from the samples were isolated. RNA sequencing was then used to determine the gene expression levels in the patient’s lymphocytes and monocytes to determine each patient’s prostate cancer-specific immune profile.

A regularized regression model was built on the training cohort to predict prostate cancer aggressiveness according to NCCN guidelines. The model was then validated in an independent cohort of biopsy-positive men (n = 706). The aggressiveness outcome was patients who were NCCN unfavorable intermediate risk or worse, who were determined to be not appropriate for active surveillance.

According to Immunis.AI, the team plans to commercialize the test across the US and Europe.

Co-author Jason Hafron, MD, chief medical officer of the Michigan Institute of Urology, concluded in the news release, “Modifying active surveillance protocols based on the patient’s immune response to their own prostate cancer is a completely novel and very exciting concept. Immunis.AI‘s liquid biopsy test represents a new frontier to developing dynamic risk-based active surveillance strategies that can improve patient care, improve the active surveillance experience, and lessen the patient burden of intensive monitoring, decreasing the need for surveillance prostate biopsies.”²

References

1. Van Neste L, Henao R, Wojno KJ, et al. Development and optimization of a subtraction-normalized immunocyte profiling signature for prostate cancer active surveillance risk stratification. J Urol. 2024;211(3):415-425. doi:10.1097/JU.0000000000003824

2. Immunis.AI announces publication, in The Journal of Urology, of results from blood-based immune profiling study for prostate cancer patients. News release. Immunis.AI. March 1, 2024. Accessed March 4, 2024. https://www.businesswire.com/news/home/20240301922573/en/Immunis.AI-Announces-Publication-in-The-Journal-of-Urology-of-Results-from-Blood-Based-Immune-Profiling-Study-for-Prostate-Cancer-Patients