A privately-held Seattle-based biotechnology company secured $1.44 million on the second of a competitive Small Business Innovation Research (SBIR) Phase IIB grant from the National Institutes of Health (NIH). The startup, Cancer Targeted Therapy (CTT), is now on its way to realizing the entirety of its three year grant totaling $3.3 million if it can continue to produce study results in collaboration with University of California, San Francisco (UCSF). The current second year funding supports the CTT1403 clincial trial. CTT1403 is a PSMA-targeted prostate cancer drug that has at least two purported features that may differentiate from other comparable therapies.
The Drug: CTT1403
CTT1403 targets Prostate Specific Membrane Antigen (PSMA), which is over-expressed on prostate cancer. Two features make CTT1403 unlike other PSMA-targeted drugs currently in development: 1) Due to a unique core scaffold, CTT’s molecules bind irreversibly to PSMA and this distinctive mode of binding enables rapid uptake of the drug within the tumor; and 2) CTT1403 is engineered to increase the circulation time of the drug in the body, which further substantially increases the dose of drug that accumulates at the tumor sites. CTT1403 is labeled with the radionuclide Lutetium-177 and once delivered to the tumor, the radionuclide acts to destroy the tumor cells. The drug was initially conceived of by Dr. Cliff Berkman, Professor, Washington State University.
CTT completed two clinical trials at UCSF with CTT1057, the companion PET diagnostic imaging agent to CTT1403, with excellent safety and imaging results for both prostate cancer and renal cell carcinoma. CTT1057 is undergoing further development for prostate cancer by CTT’s licensing partner AAA/Novartis. CTT1057 and CTT1403 serve as a theranostic pair to both diagnose and treat solid tumors that express PSMA, and are being used together in the current clinical trial.
With funding now available, the Phase 1 clinical trial continues. Conducted at University of California, San Francisco, with Dr. Rahul Aggarwal serving as Principal Investigator, the 30 to 40 patient dose escalation/expansion trial in men with advanced castration-resistant prostate cancer is designed to evidence safety and efficacy of CTT1403. The trial is now halfway done with the initial dose escalation phase. Thus far, there have been no safety issues and the pharmacokinetic data support the longer circulation time of CTT1403 in the blood stream as compared to other PSMA agents currently in trials.
Principal Investigator Point of View
Dr. Beatrice Langton-Webster, CEO of CTT, recently noted in a company issued press release, “These PSMA-targeted agents are already transforming how prostate cancer is diagnosed and treated and we are very pleased that the NIH continues to support the development of these exciting new agents. CTT1403, with its longer circulating time and better tumor targeting characteristics, offers distinct advantages in this treatment are providing the patient with cost and treatment benefits.”
The Sponsor: CTT
CTT is a biotechnology company commercializing innovative small molecules that bind pivotal enzyme targets in cancer. CTT has rationally designed and patented a targeting scaffold that recognizes the molecular target, Prostate-Specific Membrane Antigen (PSMA), with unparalleled binding characteristics, making it stand out from its competitors. PSMA is an exceptional biomarker, expressed on close to 90% of prostate tumors, with increased PSMA expression correlated with disease progression while normal tissue expression of PSMA is negative to low. CTT’s small molecule drugs are unique as they bind irreversibly to the PSMA target and are rapidly internalized by PSMA-expressing tumor cells. As a consequence of this, more of the drug reaches and stays at the tumor site. CTT’s targeting agents act as a platform to effectively and safely deliver a wide variety of diagnostic and therapeutic payloads.
CTT’s is initially targeting prostate cancer with these drugs. More than 2.9 million men in the US suffer from prostate cancer with approximately 200,000 new cases and approximately 30,000 men expected to die from the disease per year. PSMA is also expressed on the new blood vessels of other solid tumors, including colon, liver, renal cell, and lung, providing a broad market for CTT’s PSMA-targeted agents.
The company has three investigational therapies in its pipeline, including CTT1057 (PSMA-Targeted PET Imaging Agent for Prostate Cancer), CTT1403 (PSMA-Targeted Radiotherapeutic for Prostate Cancer), and CTT1700 (PSMA-Targeted Chemotherapeutic for Prostate Cancer).
The company has been active with the NIH since 2010. The company is small—appearing to employ under 10.