The FDA approved intravenous piflufolastat F 18 (Pylarify) to assist with positron emission tomography (PET) imaging of prostate-specific membrane antigen (PSMA) positive lesions in patients with suspected metastastatic prostate cancer potentially curable by surgery or therapy, as well as patients with suspected prostate cancer recurrence based on elevated serum PSA levels.
Piflufolastat F 18, a radioactive diagnostic agent delivered intravenously, is not the first drug approved for this indication—another PSMA-targeted PET imaging drug, Ga 68 PSMA-11, first gained FDA approval in December 2020 for the same population. However, Ga 68 PSMA-11 is currently only available at two sites in California, the agency explained; this new drug is expected to be distributed nationwide, increasing access to the PSMA-targeted PET imaging.
This approval was based on results from a pair of prospective clinical trials that included a total of 593 men with prostate cancer.
“In the first trial, a cohort of 268 patients with biopsy-proven prostate cancer underwent PET/CT scans performed with [piflufolastat F 18],” the FDA explained. “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 [piflufolastat F 18] PET had a clinically important rate of metastatic cancer confirmed by surgical pathology.”
The second trial, the agency continued, “enrolled 208 patients who had rising serum PSA levels after initial prostate surgery or other definitive therapy, and thus had biochemical evidence of recurrent prostate cancer. Prior to a single [piflufolastat F 18] PET/CT scan, all of these patients had baseline conventional imaging performed that did not show definite spread of prostate cancer. [Piflufolastat F 18] PET detected at least one positive lesion in at least one body region (bone, prostate bed, pelvic lymph node, other lymph nodes, or soft tissue) in 60% of these patients. In patients with positive [piflufolastat F 18] PET readings who had correlative tissue pathology from biopsies, results from baseline or follow-up imaging by conventional methods, or serial PSA levels available for comparison, local recurrence or metastasis of prostate cancer was confirmed in an estimated 85% to 87% of cases, depending on the reader.”
The most common side effects associated with use of piflufolastat F 18 were headache, altered taste, and fatigue. The FDA also warned that the drug can cause hypersensitivity reactions, particularly in patients with a history of other food or drug allergies. The agency also noted that the drug can bind to other types of cancer, as well as certain non-malignant conditions, which may lead to image interpretation errors and posssible misdiagnosis; also, the drug carries radiation risks, as it contributes to a patient’s overall long-term cumulative radiation exposure.
Piflufolstat F 18 is manufactured by Progenics Pharmaceuticals, Inc.
John McKenna, Associate Editor, BreakingMED™
Cat ID: 25
Topic ID: 78,25,730,25,192,725,73,925
