CTT begins Phase I trial of CTT1057 to treat men with high-risk metastatic prostate cancer


US-based biotechnology firm Cancer Targeted Technology (CTT) has begun its Phase I clinical trial of CTT1057 in men with high-risk metastatic prostate cancer.

CTT1057 has been developed as a positron emission tomography (PET) imaging agent labelled with a two-hour half life radio-label, fluorine-18 that is based on a small molecule core and targets an extracellular region of prostate specific membrane antigen (PSMA) with high affinity.

PSMA is a biomarker for prostate cancer mostly expressed on all prostate tumours correlated with disease progression.

CTT1057 binds to PSMA with nanomolar affinity and selectively delivers payloads to the surface and intracellular space of prostate tumour cells through the rapid internalisation of the enzyme-inhibitor complex.

The non-randomised, open label Phase I study is intended to test the safety and toletability of the PET imaging agent.

"PSMA is a biomarker for prostate cancer mostly expressed on all prostate tumours correlated with disease progression."

CTT CEO Beatrice Langton-Webster said: “Our diagnostic agent, CTT1057, will be used alone or with our companion radiotherapeutic drug, CTT1403, targeting metastatic prostate cancer, currently undergoing IND-enabling studies.”

The study is expected to enrol 20 patients in two parallel cohorts, with five patients diagnosed with prostate cancer to be included in the first cohort before they undergo radical prostatectomy.

The second cohort will include 15 patients with evidence of metastatic, castration-resistant prostate cancer.

The patients will be administered with single intravenous (IV) dose of CTT1057 and a combined PET / MR imaging will be conducted following a tracer injection.

The secondary endpoint of the trial is to test the sensitivity and specificity of CTT1057 PET imaging on a lesion-by-lesion basis compared with standard imaging in metastatic prostate cancer.