Preclinical studies have found that two new, simpler, and more readily available radiopharmaceuticals were effective in diagnosing and treating primary and metastatic prostate cancer.

Researchers at Memorial Sloan Kettering Cancer Center (MSK) in New York City developed the new pair of theranostic agents, which target prostate-specific membrane antigen (PSMA), and that can also be synthesized easily and inexpensively without using specialized equipment.

The research was presented at the recent Society of Nuclear Medicine and Molecular Imaging virtual annual meeting.
For the study, the researchers developed novel radioiodinated PSMA-targeting radiopharmaceuticals called 124/131I-MSK-PSMA1, which use iodine, a widely-available and economical therapeutic agent.

“The reason why we wanted to focus on iodine is because it available everywhere,” Dr. Kishore Pillarsetty, a radiochemist at MSK and the paper’s senior author, told HCB News. “Generating the compound is one of the challenges.”

The research team synthesized 124/131I-MSK-PSMA1 and performed in vitro saturation binding assays in prostate cancer cells, which were later harvested and counted for radioactivity using a gamma counter. In vivo PET imaging and biodistribution studies were then performed on mice with prostate cancer xenografts. Both studies produced favorable results, lowering the tumor load in mice, according to the researchers.

The study also showed that the radiopharmaceuticals produce no volatile byproducts, which eliminates the need for expensive protective equipment.

There are plans to conduct a Phase 1 imaging-based clinical trial for the agents using human participants, and the researchers are in the process of writing a grant.

“We know that it’s going to work, but what we don’t know is a head-on comparison” to other agents for measuring therapeutic efficacy, Pillarsetty said.

The plan is to develop a kit to allow for easy on-site production.

“We are very optimistic about the potential of this,” Pillarsetty said.

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