IsoPSA™ is a structure-based (rather than concentration-based) reagent that agnostically interrogates the entire spectrum of structural changes of complex PSA. It does so by partitioning isoforms of prostate-specific antigen (PSA) with an aqueous two-phase solution.

The IsoPSA™ assay is currently involved in a multi-center prospective pilot study and not available in the United States. The interim analysis of the study has been published in European Urology.

Why IsoPSA™

Prostate-specific antigen, the current gold standard in prostate cancer detection, is distinct from virtually all other cancer biomarkers because of its almost exclusive specificity to the prostate, allowing direct assessment of physiological conditions in the gland with a simple blood test. Unfortunately, PSA is tissue- but not cancer-specific, and overdiagnosis and overtreatment of PSA-detected, biologically insignificant cancers are widely recognized as key limitations in its clinical utility.

IsoPSA™ Performance

An interim analysis of our multi-center prospective pilot study led by Eric Klein, MD, is provided below:


Table 1. Performance metrics vs. PSA at selected cutoff risk probability values.


Figure 1A. ROC for PCa vs. no cancer
(ROC of the model:  Solid line = IsoPSA; dotted line = Standard PSA)


Figure 1B. ROC for High Grade PCa vs. low grade cancer/benign histology
(ROC of the model:  Solid line = IsoPSA; dotted line = Standard PSA)


Any clinical researchers interested in learning more about the ongoing clinical study should contact us at