Molecular Insight Pharmaceuticals (MIP) has presented positive data from Phase 1 clinical studies comparing Trofex (123I-MIP-1072), its lead molecular imaging candidate for the diagnosis and monitoring of metastatic prostate cancer, and ProstaScint (111In-capromab pendetide), an imaging radiopharmaceutical for the visualisation of metastatic prostate cancer.
Data presented at the Annual Congress of the European Association of Nuclear Medicine in Vienna demonstrated that Trofex rapidly detected prostate cancer localised in the prostate bed, soft tissues and bone within four hours post injection.
In contrast, ProstaScint required five days before imaging and was unable to detect metastatic disease in bone.
Data from two completed Phase 1 studies and preliminary data from one ongoing Phase 1 study were presented in an abstract titled: Detection of Metastatic Prostate Cancer (PCa) in Soft Tissue, Bone, and Prostate with 123I-MIP-1072: A Comparison with 111In-Capromab Pendetide.
Molecular Insight reported that in this limited group of patients Trofex visualised lesions in the prostate, lymph nodes and bone at four hours after injection, confirming that targeting the extracellular domain of PSMA with small molecules is a viable approach for imaging metastatic prostate cancer.
In comparison to Trofex, ProstaScint requires five days for optimal imaging. In this study, ProstaScint was unable to detect bone metastases and required supplementary blood pool imaging for confirmation of lymph node metastases along the normal vasculature.
In the second presentation at the EANM Annual Congress, Molecular Insight scientists have developed an analog of Trofex that carries the therapeutic iodine radionuclide, I-131, creating a molecularly targeted radiotherapeutic that specifically binds PSMA on prostate cancer cells and offers the potential for treatment of metastatic prostate cancer.
In an abstract titled: Inhibition of Human Prostate Cancer Growth by Targeting Prostate Specific Membrane Antigen (PSMA) using an I-131 labeled small molecule inhibitor, researchers reported that a Molecular Insight compound, 131I-MIP-1375, was effective at inhibiting, in a dose-related manner, the growth of human PSMA-expressing prostate tumors in a mouse model.
The company said that the preclinical data provide a basis for advancing the development of 131I-MIP-1375 as a targeted radiotherapeutic option in the treatment of prostate cancer.