In this study, the NADiA (Nucleic Acid Detection ImmunoAssay) PSA Assay detected levels and increasing levels of prostate specific antigen (PSA) that were previously undetectable using conventional ultra sensitive assays, thus potentially enabling the detection of biochemical recurrence (BCR) an average 2-1/2 years earlier than with the most sensitive commercially available tPSA assays.
Collectively, the 85 patient cohort had 435 serial blood samples collected between 100 and 3,200 days after a radical prostatectomy and all 85 men had an initial serum PSA level that could not be detected (< 100 pg/mL) using a conventional PSA assay. In the study, retained blood samples of 42 men that had confirmed biochemical recurrence of PSA were compared to 42 men that did not recur according to results from an ultrasensitive experimental research PSA assay. Results using the NADiA PSA assay correlated very well with the research PSA assay and showed excellent clinical concordance for identifying the men with and without biochemical recurrence. The difference in PSA concentrations between these two patient groups was highly statistically significant.