12 November 2018 - - US-based biotechnology company Cancer Targeted Technology has filed an Investigational New Drug Application with the FDA to move forward a radiotherapeutic drug, CTT1403, into human clinical trials for prostate cancer, the company said.

CTT1403 is a peptidomimetic drug that targets Prostate Specific Membrane Antigen. PSMA is over-expressed on prostate cancer and this expression increases as the cancer metastasizes and becomes hormone-resistant.

Unlike other drugs, CTT's molecules bind irreversibly to PSMA. This distinctive mode of binding enhances uptake and results in rapid and extensive internalization of these drugs by tumor cells, leading to increased uptake within the tumor.

CTT1403 is labeled with the radionuclide 177-Lutetium and, unlike other PSMA-targeted drugs in clinical development, contains a unique albumin binding component.

The albumin binding moiety on CTT1403 acts to increase the circulation of the drug in the body and further substantially increases the dose of drug that accumulates at the tumor sites.

Once targeted to the tumor, the radionuclide on CTT1403 leads to tumor cell destruction.

According to the company, CTT1403 has shown excellent safety results to date in animal studies and CTT1403 treatment results in prolonged survival of animals with prostate cancer tumors.

CTT recently completed clinical trials of CTT1057, the companion PET diagnostic to CTT1403, with excellent safety and imaging results.

CTT1057 is undergoing further development and commercialization by CTT's licensing partner AAA/Novartis. CTT1057 and CTT1403 can act as a theranostic pair to both diagnose and treat prostate cancer.

Phase I clinical trials for CTT1403 are expected to start January, 2019.