Cancer Targeted Technology Commences Phase I Clinical Trial of CTT1057, a Diagnostic Imaging Agent for Prostate Cancer

SEATTLE--(BUSINESS WIRE)--Cancer Targeted Technology (CTT), a privately-held Seattle-based biotechnology firm focusing on small molecules that target pivotal enzyme targets on cancer, announced that a Phase I clinical trial has commenced in men with high risk metastatic prostate cancer. In late August, the Food and Drug Administration cleared CTT’s first Investigational New Drug Application (IND) for a Positron Emission Tomography (PET) imaging agent, CTT1057, labeled with a two-hour half life radiolabel, fluorine-18, and targeting Prostate-Specific Membrane Antigen (PSMA). PSMA is over-expressed on prostate cancer and this expression increases as the cancer metastasizes and becomes castrate-resistant. CTT’s phosphoramidate-based agents bind irreversibly to PSMA and unlike other agents targeting PSMA, this distinctive mode of binding enhances uptake and internalization by tumor cells leading to increased accumulation of the drug and radiolabel within the tumor. The first patient in this trial was imaged in early November and the study is supported by a $2M Small Business Innovation Research (SBIR) grant.

“FDA clearance and start of our first clinical trial are significant milestones for CTT as we transition to a clinical phase company. CTT’s PSMA-targeted drugs are unique and unlike anything else that has been studied to date,” said Beatrice Langton-Webster, CTT CEO and Principal Investigator on the SBIR. “Our diagnostic agent, CTT1057, will be used alone or with our companion radiotherapeutic drug, CTT1403, targeting metastatic prostate cancer, currently undergoing IND-enabling studies.”

Automated radiolabeling of the drug and the clinical trials are being conducted at University of California, San Francisco (UCSF). The Principal Investigator for the clinical trial is Dr. Rahul Aggarwal, and the radiolabeling is directed by UCSF collaborator, Dr. Henry VanBrocklin, Director of the Radiopharmaceutical Research Program, who worked with CTT on the initial development of CTT1057, along with Dr. Cliff Berkman, Professor of Chemistry at Washington State University, who first discovered and synthesized the drug.

Dr. VanBrocklin commented: “We are excited to initiate the clinical phase of development of this new imaging agent and look forward to the results of these key studies.”

This CTT-sponsored Phase I trial is entitled “A Phase 1 Trial for Evaluation of the Safety, Pharmacokinetics, and [18F] Radiation Dosimetry of CTT1057, a Small Molecule Inhibitor of Prostate Specific Membrane Antigen (PSMA).” The primary objective of this trial is to evaluate the safety and tolerability of CTT1057. An additional endpoint includes the assessment of sensitivity and specificity of CTT1057 PET imaging on a lesion-by-lesion basis as compared with standard imaging in metastatic prostate cancer. Twenty patients will be enrolled in parallel in two cohorts: Cohort A will enroll patients with prostate cancer prior to radical prostatectomy (N = 5) and Cohort B will enroll patients with evidence of metastatic castration-resistant prostate cancer (N = 15). The study is currently enrolling and is expected to conclude in mid 2017. More information on the trial can be found at


Cancer Targeted Technology
Dr. Langton-Webster