FDA Approves First PSMA-Targeted PET Imaging Drug for Men With Prostate Cancer

A new type of drug has been approved by the U.S. Food and Drug Administration (FDA) for use in PET imaging of men with prostate cancer.

The drug, Gallium 68 PSMA-11 (Ga 68 PSMA-11), is a radioactive tracer. It was approved for PET imaging in men whose prostate cancer is suspected of having spread to other areas of the body. The tracer may also be used in men who have already had successful treatment for prostate cancer but who have high PSA levels. An elevated PSA level can mean that prostate cancer has returned.^1,2

A PET/CT scan is an imaging test that is effective at detecting cancer. The scan that uses Ga 68 PSMA-11 can detect prostate cancer much earlier than other types of scans. Because of this, it may help improve the treatment of many men living with prostate cancer.^1,3

How does Gallium 68 PSMA-11 work?

Before undergoing a PET/CT scan, a man with prostate cancer receives an intravenous injection of the tracer Ga 68 PSMA-11. During the scan, the tracer binds to a protein that is found on the surface of prostate cancer cells. This protein is called prostate-specific membrane antigen (PSMA). Using the PET/CT scanner, doctors can “see” the PSMA. This lets them know if cancer is present and where it is in the body.^1,3

The importance for prostate cancer

Traditionally, men with prostate cancer may have a conventional CT scan (which uses a form of X-rays) and a bone scan to see if their cancer has spread. However, neither of these tests are good at finding very small tumors. Plus, bone scans can find abnormalities that may have been caused by something besides cancer. This leads to “false-positive” findings and may result in additional unnecessary tests.^1,3

Two other PET drugs have been approved for prostate cancer imaging, but they are only approved for use in men whose cancers may be coming back. Ga 68 PSMA-11 is the first drug that can be used when doctors suspect that prostate cancer may have spread.¹

Researchers now are looking at how PET-CT scans may change treatment outcomes for men living with prostate cancer. Eventually, the FDA may approve a PET-CT scanning technology that could not only “see” prostate tumors but could also deliver drugs or radiation directly to the tumors without affecting normal tissue.¹

Evidence from clinical trials

The approval of Ga 68 PSMA-11 was based on the results of 2 clinical trials. The trials included 960 men with prostate cancer who each received 1 injection of Ga 68 PSMA-11.^2-4

In the first trial, the men who underwent PET/CT or PET/MRI scans performed with Ga 68 PSMA-11 were scheduled to have prostate surgery. After their scan, the doctors were able to confirm that in some men, their cancer had already spread out of the prostate. Once cancer has spread, the recommended treatment option may not be surgery. This means that having a PET scan may spare certain people with prostate cancer from having an unnecessary operation.^2-4

The second trial included men who had a high PSA level. When the men had the scan that uses Ga 68 PSMA-11, doctors could see if they had cancer that had spread or recurred. This is important because the men’s treatment plan could be tailored to the doctor’s findings.^2-4

The most common side effects of Ga 68 PSMA-11 reported in the clinical trials were nausea, diarrhea, and dizziness.^2-4

What to know about Gallium 68 PSMA-11

There is a risk for misdiagnosis with Ga 68 PSMA-11. A negative PET scan does not rule out the presence of prostate cancer, and a positive scan does not confirm the presence of prostate cancer.⁴

There are radiation risks with Ga 68 PSMA-11 because the drug contributes to a person’s overall, long-term cumulative radiation exposure. This type of exposure is linked to an increased risk of cancer.⁴

Before taking Ga 68 PSMA-11, tell your doctor about any other drugs, vitamins, or supplements you are taking. This includes over-the-counter drugs.

For more information, read the full prescribing information of Gallium 68 PSMA-11.