Press release
Monopar and NorthStar Announce Patent Filing on Promising Radiopharmaceutical Discovery
Potential to significantly improve the yield of Actinium-based radiopharmaceuticalsWILMETTE, Ill. and BELOIT, Wis., May 24, 2021 (GLOBE NEWSWIRE) -- Monopar
About this update from Monopar Therapeutics Inc.
[{"type":"text","content":"Potential to significantly improve the yield of Actinium-based radiopharmaceuticalsWILMETTE, Ill. and BELOIT, Wis., May 24, 2021 (GLOBE NEWSWIRE) -- Monopar Therapeutics Inc. (Nasdaq: MNPR) and NorthStar Medical Radioisotopes, LLC, today announced the filing of a provisional patent with the U.S. Patent and Trademark Office (USPTO) titled “Bio-Targeted Radiopharmaceutical Compositions Containing Ac-225 and Methods of Preparation.” Radiopharmaceutical therapy is a promising approach to treat cancer and other diseases using radioactive metals bound with proteins/antibodies to target and kill cells. Actinium-225 (Ac-225) is emerging as a radioactive isotope of choice for radiopharmaceuticals due to favorable properties such as its long half-life, high potency, and induction of localized cell death. This provisional patent relates to the unexpected observation by Monopar and NorthStar that using the metal binding agent 3,6,9,15-tetraazabicyclo[9.3.1]pentadeca-1(15),11,13-triene-3,6,9-triacetic acid (PCTA) to attach Ac-225 to antibodies resulted in nearly 100% binding of Ac-225 to the PCTA-antibody conjugates. If validated through further evaluation, it could potentially improve efficacy and safety and enhance manufacturing efficiency of Actinium-based radiopharmaceuticals. Based on Monopar and NorthStar’s work to date, PCTA-antibody conjugates appear to bind Ac-225 and its daughter ions such as Bi-213 with high affinity. This could be important in the situation of transportation delays resulting in Ac-225 decaying during transport. Furthermore, when compared to DOTA (the standard binding agent for attaching Ac-225 to an antibody), PCTA-antibody conjugates displayed a significantly higher affinity to Ac-225. This high affinity binding may decrease the amount of Ac-225 and its daughter ions that detach from the antibody, which could potentially increase efficacy and reduce off-target toxicity and enable higher dosing. Monopar and NorthStar plan to explore both internal development and out-licensing opportunities of this promising approach in Actinium-based radiopharmaceuticals. “Actinium is quickly becoming a premier radioisotope in cancer-targeting therapies, but its potential is limited due to its price and scarcity,” said James Harvey, PhD, Chief Scientific Officer of NorthStar. “Enabling radiopharmaceutical manufacturers and drug d...