Monopar Therapeutics Inc. ?and NorthStar Medical Radioisotopes, LLC announced an expansion of their radiopharmaceutical collaboration along with a new radiolabeled MNPR-101 imaging candidate designated as MNPR-101-Zr. Based on promising recently generated preclinical imaging results with MNPR-101-Zr showing high uptake across multiple tumor types, the companies also committed to additional funding with the aim of initiating a first-in-human imaging study with MNPR-101-Zr as early as the end of this year. MNPR-101-Zr is a zirconium-89 labeled version of MNPR-101, a highly selective antibody against the urokinase plasminogen activator receptor (uPAR).

Positron emission tomography (PET) imaging of preclinical mouse models for triple-negative breast, colorectal, and pancreatic tumors displayed high and selective uptake of MNPR-101-Zr in these uPAR-expressing tumors. These proof-of-concept studies provide support for a first-in-human PET imaging study with MNPR-101-Zr and a future therapeutic study using the previously announced actinium-225 labeled radioimmunotherapeutic version of MNPR-101. Overall, the imaging results demonstrate the potential utility of MNPR-101 as a precision targeting agent for both imaging and therapy in multiple cancer indications.