Trial results with Ga 68 PSMA-11
The safety and efficacy of Ga 68 PSMA-11 were evaluated in two prospective clinical trials with a total of 960 men with prostate cancer, each of whom received one injection of the product.
The first trial involved 325 patients with biopsy-proven prostate cancer who underwent PET/CT or PET/MRI scans performed with Ga 68 PSMA-11.
“These patients were candidates for surgical removal of the prostate gland and pelvic lymph nodes and were considered at higher risk for metastasis. Among the patients who proceeded to surgery, those with positive readings in the pelvic lymph nodes on Ga 68 PSMA-11 PET had a clinically important rate of metastatic cancer confirmed by surgical pathology,” the FDA noted.
“The availability of this information prior to treatment is expected to have important implications for patient care,” the FDA commented. “For example, it may spare certain patients from undergoing unnecessary surgery.”
The second trial enrolled 635 patients with rising serum PSA levels after initial prostate surgery or radiotherapy. All patients received a single Ga 68 PSMA-11 PET/CT scan or PET/MRI scan.
About three-quarters of patients (74%) had at least one positive lesion detected by Ga 68 PSMA-11 PET in at least one region – bone, prostate bed, pelvic lymph node, or extra-pelvic soft tissue.
“In patients with positive Ga 68 PSMA-11 PET readings who had correlative tissue pathology from biopsies, results from baseline or follow-up imaging by conventional methods, and serial PSA levels available for comparison, local recurrence or metastasis of prostate cancer was confirmed in an estimated 91% of cases,” the FDA noted.
“Thus, the second trial demonstrated that Ga 68 PSMA-11 PET can detect sites of disease in patients with biochemical evidence of recurrent prostate cancer, thereby providing important information that may impact the approach to therapy,” the agency added.
The FDA also noted that no serious adverse reactions were attributed to Ga 68 PSMA-11. The most common adverse reactions were nausea, diarrhea, and dizziness.
The FDA said there is a risk for misdiagnosis because Ga 68 PSMA-11 binding may occur in other types of cancer, and certain nonmalignant processes may lead to errors in interpreting images. In addition, there are radiation risks because Ga 68 PSMA-11 contributes to a patient’s overall long-term cumulative radiation exposure, which is associated with an increased risk for cancer.
A version of this article originally appeared on Medscape.com.