Wisconsin Alumni Research Foundation

Therapeutics & Vaccines
Therapeutics Vaccines
PSMA-Targeting Ligands with Optimal Properties for Imaging and Therapy
WARF: P210215US02

Inventors: Reinier Hernandez, Anatoly Pinchuk

The Wisconsin Alumni Research Foundation is seeking commercial partners interested in developing a novel PSMA radionuclide disease-targeting agent for imaging and treating prostate and breast cancers.
Theranostics, a term derived from a combination of therapeutics and diagnostics, is an emerging field of medicine where specific radionuclide disease-targeting agents are used to diagnose and treat medical conditions. One recently developed theranostics agent targets the prostate-specific membrane antigen (PSMA), a protein that can be overexpressed in metastases originating from both prostate and breast tumors. This agent is used for PET imaging and for targeted radiotherapy using high dose radioisotopes.

However, currently available tracers (PSMA-11, PSMA-617, PSMA-R2, EB-PSMA and PSMA I&T) remain bound to the cancer cells for only a short time, have limited tumor retention and are excreted through the renal system, overburdening the patient’s kidneys.
The Invention
Researchers at UW-Madison have developed a novel PSMA radionuclide disease-targeting agent, PSMA281. This new agent has improved tumor retention, is cleared mostly by the liver (easing the kidney burden) and has improved efficacy compared to PSMA-617 at similar doses in mice. The novel agent is extremely versatile and can be composed of various imaging and therapeutical radioactive isotopes.

The novel agent allows excretion mechanisms to be controlled by regulating chemical characteristics of the molecule. It also enables the treatment of prostate cancer by inhibiting cancer growth and retarding disease advancement. PSMA281 allows the detection and imaging of prostate cancer when used with imaging radioisotopes, which can be done either via PET or SPECT medical imaging. The imaging capability also makes it suitable to be a tool in the staging of cancer and in the evaluation of therapy efficacy. Finally, quantification of the imaging signal strength allows for determining an effective dose for the subsequent delivery of targeted radiation therapy. Recent studies have found that more than 55% of breast cancers are PSMA-positive, which makes this compound a potentially viable option to treat PSMA-positive breast cancers.
  • Imaging prostate and breast cancer for diagnosing, staging and treatment efficacy assessment
  • Treating prostate and breast cancer via targeted radiation therapy using high dose radioisotopes
  • Determining the efficacious dose for targeted radiotherapy Imaging and treatment can be done in vivo, ex vivo or in vitro.
Key Benefits
  • In targeting cancer cells, the novel agent is more efficacious and less harmful to the patient (most importantly, the salivary glands) than current agents.
  • The developed agent can be prepared without an albumin binder, which enables the pharmacokinetics to be tuned by adjusting the length of the carbon chain of the linker.
  • The agent allows for imaging cancer with PET and SPECT medical imaging. It can be prepared to be electrically neutral.
Stage of Development
Qualitative and quantitative studies were conducted using mice models and demonstrated longer blood circulation, greater tumor binding, less kidney clearance and better long-term dissociation from the tumor when compared to available agents as well as improved efficacy when dosing this compound versus PSMA-617 (unpublished data).

The development of this technology was supported by WARF Accelerator. WARF Accelerator selects WARF's most commercially promising technologies and provides expert assistance and funding to enable achievement of commercially significant milestones. WARF believes that these technologies are especially attractive opportunities for licensing.
Additional Information
For More Information About the Inventors
For current licensing status, please contact Rafael Diaz at [javascript protected email address] or 608-960-9847