In January, Dr. Tagawa and his team began conducting trials in which patients are injected with this highly targeted form of radiation therapy. The radioactive particle known as lutetium-177, or Lu-177, is attached to a small molecule called 617 — the PSMA-seeking missile. The duo is then injected into the bloodstream of men with metastatic prostate cancer. Successive groups of patients will continue to get ever-higher doses for better results.
“We’ll keep going up until we start to see any significant side effects,” says Dr. Tagawa. “In theory, we can even try attaching both radiation and a drug.”
Some refer to this type of high-tech cancer treatment as “personalized medicine.” Dr. Tagawa prefers “precision medicine.”
“In a way, this would be the most tumor-targeted treatment out there — only going to places where PSMA exists,” says Dr. Tagawa. “And the nice thing about prostate cancer is that it’s pretty much the only site in the body with a significant amount of PSMA.”
Better still, Dr. Tagawa says that theoretically, using anti-PSMA carriers and PSMA-sensitive radioisotopes to seek and destroy tumor cells should work for 90 percent of patients.
“As long as we can get a high enough dose of radiation to the tumor, the cell will die and we can avoid the rest of the body,” he explains. “This is going to help a lot of people around the world.”