Identification of a high-risk immunogenic prostate cancer patient subset as candidates for T-cell engager immunotherapy and the introduction of a novel albumin-fused anti-CD3 × anti-PSMA bispecific design.

BACKGROUND: Cancer immunotherapies such as bispecific T-cell engagers have seen limited adoption in prostate cancer (PC), possibly due to differing levels of cancer receptor expression and effector T-cell infiltration between patients and inherent defects in T-cell engager design. METHODS: CD8+ T-cell infiltration and PSMA expression were determined by RNA sequencing of primary PC tissue samples from 126 patients with localised PC and 17 patients with metastatic PC. Prognostic value was assessed through clinical parameters, including CAPRA-S risk score. A panel of albumin-fused anti-CD3 × anti-PSMA T-cell engagers with different neonatal Fc receptor (FcRn) affinity were characterised by flow cytometry, Bio-Layer Interferometry and functional cellular assays. RESULTS: A subset of patients with localised (30/126 = 24%) and metastatic (10/17 = 59%) PC showed both high PSMA expression and high CD8+ T-cell enrichment. The High/High phenotype in localised PC associated with a clinically high-risk cancer subtype, confirmed in an external patient cohort (n = 550, PRAD/TCGA). The T-cell engagers exhibited tunable FcRn-driven cellular recycling, CD3 and PSMA cellular engagement, T-cell activation and PSMA level-dependent cellular cytotoxicity. CONCLUSION: This work presents an albumin-fused bispecific T-cell engager with programmable FcRn engagement and identifies a high-risk PC patient subset as candidates for treatment with the T-cell engager class of immuno-oncology biologics.

Danish Prostate Cancer Consortium Study 1 (DPCC-1) protocol: Multicentre prospective validation of the urine-based three-microRNA biomarker model uCaP.

INTRODUCTION: The primary objective of the Danish Prostate Cancer Consortium Study 1 (DPCC-1) is to provide validation for a novel urine-based microRNA biomarker, called uCaP, for a diagnosis of prostate cancer. METHODS AND ANALYSIS: Eligible participants are biopsy naïve men aged ≥18 years with prostate-specific antigen (PSA) levels ≥3 ng/mL, who are referred to prostate MRI due to suspicion of PC at one of the following three major urology/uroradiology centers: Aarhus University Hospital, Herlev & Gentofte University Hospital, or Odense University Hospital, where MRI and targeted biopsy are implemented in clinical use. Exclusion criteria include previous diagnosis of urogenital cancer, contraindication to MRI, gender reassignment treatment or PSA level >20 ng/mL. The participants will be asked to donate a urine sample in connection with their MRI. The study is observational, uses a diagnostic accuracy testing setup and will integrate into the current diagnostic pathway.We will measure the levels of the three microRNAs in the uCaP model (miR-222-3 p, miR-24-3 p and miR-30c-5p) in extracellular vesicle-enriched cell-free urine samples, to assess if uCaP can improve specificity and retain sensitivity for International Society of Urological Pathology Grade Group ≥2 PC, when used as a reflex test to PSA ≥3 ng/mL. We hypothesise that uCaP can improve selection for prostate MRI and reduce the number of unnecessary scans and biopsies. ETHICS AND DISSEMINATION: This study is approved by the Central Denmark Region Committee on Health Research Ethics (reference number: 1-10-72-85-22). All participants will provide written informed consent. Study results will be published in peer-reviewed journals and presented in scientific meetings. TRIAL REGISTRATION NUMBER: NCT05767307 at clinicaltrials.gov.