# Clinical Evaluation of an Innovative PSMA-targeted Radiotherapy, CTT1403, in Prostate Cancer > **NIH NIH R44** · CANCER TARGETED TECHNOLOGY, LLC · 2020 · $1,441,580 ## Abstract PROJECT ABSTRACT Prostate-Specific Membrane Antigen (PSMA) is an ideal tumor biomarker as it is expressed on >90% of all prostate cancers and expression increases as the cancer progresses. Cancer Targeted Technology (CTT) has developed a unique phosphoramidate-based scaffold that binds irreversibly to PSMA leading to > 90% rapid internalization and selective accumulation in tumor cells. With previous SBIR grant support, CTT created an 18F- labeled PET diagnostic imaging agent, CTT1057, and in Aug 2017 completed a Phase I clinical trial in patients with metastatic prostate cancer. CTT1057 demonstrated significant uptake in PSMA-avid bone and visceral lesions with far greater specificity and sensitivity than standard of care scans. In Jan 2018, CTT licensed this PET imaging agent to Advanced Accelerator Applications/Novartis. Prostate cancer is radiosensitive, but only Radium-223, which is neither specific nor selective, has been commercialized as a radiotherapeutic for advanced stage disease. Under an additional SBIR Phase I/II fast track contract, CTT modified the original CTT1057 PSMA-binding scaffold to develop a specific and potent companion therapeutic, CTT1403, radiolabeled with 177Lu. CTT1403, unlike other PSMA-targeting agents under development, is highly innovative in that it binds irreversibly to PSMA and uses an albumin-binding motif to dramatically slow clearance, resulting in an unprecedented tumor uptake of >80% injected dose/g of tumor tissue and a significant survival advantage in animal models. Under the SBIR Phase II contract, GMP-manufacturing, radiolabeling and IND- enabling pharmacology, dosimetry and initial animal safety studies were completed. An FDA pre-IND meeting was held, and the IND will be filed Q4 2018. The objective of this SBIR Phase IIB application is to support the first in human Phase 1 clinical trial of CTT1403 and to position the drug for further clinical development and rapid commercialization. Specific aims: AIM 1: Phase 1 clinical trial of CTT1403 in metastatic castration-resistant prostate cancer (mCRPC), assessing safety and initial efficacy: CTT will conduct an accelerated dose escalation/expansion trial in patients with mCRPC. Increased uptake of the albumin-binding, PSMA-targeted, 177Lu-labeled CTT1403 drug is hypothesized to translate into a meaningful survival advantage. AIM 2: Assess GLP late radiation safety: CTT will evaluate long term tolerance of repeat-dose CTT1403 in dogs to meet FDA late radiation safety recommendations prior to start of Phase 2 trials. AIM 3: Process development in support of further clinical development: CTT will develop and scale CTT1403 manufacturing methods in support of multiple dose trials. This innovative work harnesses the ideal performance of a cell-penetrating irreversible small-molecule PSMA-targeted drug that uses albumin binding to increase circulation half-life and tumor targeting and decrease renal toxicity. CTT1403 should have considerable significance for me... ## Key facts - **NIH application ID:** 9973060 - **Project number:** 5R44CA239461-05 - **Recipient organization:** CANCER TARGETED TECHNOLOGY, LLC - **Principal Investigator:** Beatrice Langton-Webster - **Activity code:** R44 (R01, R21, SBIR, etc.) - **Funding institute:** NIH - **Fiscal year:** 2020 - **Award amount:** $1,441,580 - **Award type:** 5 - **Project period:** 2019-07-02 → 2022-06-30 ## Primary source NIH RePORTER: https://reporter.nih.gov/project-details/9973060 ## Citation > US National Institutes of Health, RePORTER application 9973060, Clinical Evaluation of an Innovative PSMA-targeted Radiotherapy, CTT1403, in Prostate Cancer (5R44CA239461-05). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9973060. Licensed CC0. --- *[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*