December 01, 2020
2 min read
The FDA today approved Gallium 68 PSMA-11 as the first drug for PET imaging of prostate-specific membrane antigen-positive lesions in men with prostate cancer, according a press release from the agency.
Gallium 68 PSMA-11 (Ga 68 PSMA-11; University of California, Los Angeles and University of California, San Francisco) — an IV-administered radioactive diagnostic agent — is indicated for men with suspected prostate cancer metastasis who may be cured by surgery or radiation therapy, and for men with suspected prostate cancer recurrence based on elevated prostate-specific membrane antigen (PSMA) levels.
Ga 68 PSMA-11 binds to PSMA, which is usually elevated in prostate cancer cells. Ga 68 PSMA-11 is then imaged by PET to indicate the presence of PSMA-positive prostate cancer lesions in the patient’s tissues. According to the FDA, Ga 68 PSMA-11 may be used to spare men from unnecessary surgery and to detect sites of disease in men with biochemical evidence of recurrence.
Two other PET drugs are approved for prostate cancer imaging — F 18 fluciclovine (Axumin, Blue Earth Diagnostics) and C 11 choline — but these are approved only for use in men with suspected cancer recurrence.
“Ga 68 PSMA-11 is an important tool that can aid health care providers in assessing prostate cancer,” Alex Gorovets, MD, acting deputy director of the Office of Specialty Medicine in FDA’s Center for Drug Evaluation and Research, said in the release. “With this first approval of a PSMA-targeted PET imaging drug for men with prostate cancer, providers now have a new imaging approach to detect whether or not the cancer has spread to other parts of the body.”
The approval was based, in part, on data from a prospective trial of 325 men with biopsy-proven prostate cancer who were candidates for surgery and at high risk for metastasis and who underwent PET/CT or PET/MRI after receiving Ga 68 PSMA-11. A “clinically important” proportion of men who had positive pelvic lymph nodes based on the Ga 68 PSMA-11 PET reading had metastatic cancer confirmed by surgical pathology, according to the release.
In another trial, 635 men with rising serum PSA levels after initial surgery or radiotherapy received a Ga 68 PSMA-11 PET/CT or PET/MRI scan. Of them, 74% had at least one positive lesion in at least one body region detected by Ga 68 PSMA-11 PET. The local recurrence or metastasis was confirmed in 91% of cases.
The most common adverse events associated with Ga 68 PSMA-11 included nausea, diarrhea and dizziness. The agent also carries the risk for misdiagnosis, as it can bind to other types of cancer or some nonmalignant processes, according to the release.