CTT’s lead therapeutic product, CTT1403, is a PSMA-targeted 177Lu-labeled agent for prostate cancer that can has superior binding characteristics, long circulation half-life, enhanced tumor uptake and unparalleled anti-tumor efficacy. CTT1403 will specifically deliver the radionuclide, 177Lu, minimizing toxic side effects and more effectively treating metastatic prostate cancer and other tumors where PSMA is expressed. Recognizing the same PSMA target and utilizing the same binding region, CTT1403 and its companion agent, CTT1057, can be used as a theranostic pair to effectively detect and treat PSMA positive tumors.
Two features make CTT1403 unique and unlike other PSMA-targeted drugs currently in development: 1. CTT’s molecules bind irreversibly to PSMA and this distinctive mode of binding enhances rapid uptake of the drug within the tumor; and 2. CTT1403 contains an albumin binding component that increases circulation of the drug in the body and further increases the dose of drug that accumulates at the tumor sites.
CTT1403 has strong pre-clinical data, showing markedly increased survival and reduction in tumor growth in animal models growing prostate tumors that express PSMA as shown in the survival curve. Animals treated with control compounds survive 40-58 days, while 90% of animals treated with CTT1403 are alive at day 120 and 8/10 animals are cured at the end of the study. CTT1403 has completed all manufacturing and IND-enabling preclinical pharmacology and early safety studies and an IND was filed with FDA in October, 2018 and approved in November, 2018.
Distinguishing Features of CTT1403
- Radiotherapy agent for prostate cancer with superior binding characteristics, long circulation half-life, enhanced tumor uptake and anti-tumor efficacy
- Recognizes a validated biomarker, PSMA, in a cancer with an unmet need
- Possibility for expansion into other cancers based on PSMA expression in the neovasculature
- Strong patent protection
Continuing development of CTT1403
Clinical trials for CTT1403 started in May 2019. The trial is an accelerated dose escalation/expansion trial in men with castrate resistant prostate cancer. CTT recently completed clinical trials at UCSF with CTT1057, the companion PET diagnostic to CTT1403, with excellent safety and imaging results. CTT1057 and CTT1403 are intended to act as a theranostic pair to both diagnose and treat prostate cancer and are being used together in the current Phase I clinical trial.The trial details can be found on clinicaltrials.gov (NCT03822871).