FDA OKs New PSMA-PET Tracer for Prostate Cancer Detection

— Piflufolastat F 18 to be commercially available across entire U.S. by year's end, drugmaker says

MedicalToday
FDA APPROVED piflufolastat F-18 (PYLARIFY) over a photo of a PET/CT scanning machine

The FDA on Thursday approved piflufolastat F 18 (Pylarify), a prostate-specific membrane antigen (PSMA) PET imaging agent for the detection of prostate cancer, .

Piflufolastat F 18 is indicated for use in men with suspected metastasis who are candidates for initial definitive therapy or for those with biochemical recurrence based on rising prostate-specific antigen (PSA) levels.

The radioactive diagnostic agent will be immediately available to imaging center in parts of the mid-Atlantic and southern regions of the U.S. and available throughout the rest of the country by the end of the year, the company said.

"Pylarify can detect the spread of disease well before standard imaging and can be a transformative diagnostic tool that helps clinicians develop treatment plans based on a much more accurate understanding of a patient's distribution of disease," said Michael Morris, MD, of Memorial Sloan Kettering Cancer Center in New York City, in a statement.

Approval was based on results from the CONDOR and OSPREY trials, in which piflufolastat F 18 was evaluated in 593 men with various stages of prostate cancer.

In OSPREY, use of piflufolastat F 18 in PET imaging to identify distant disease demonstrated a greater specificity and positive predictive value than conventional imaging for men at risk for metastatic prostate cancer prior to their initial therapy. Availability of this information is expected to have important implications for care, FDA noted in its , including the potential for avoiding unnecessary surgeries.

In CONDOR, the radiotracer demonstrated high correct localization and detection rates for men with biochemical recurrent prostate cancer, including in those with low PSA levels. All patients had baseline scans with conventional imaging that failed to definitively show cancer spread, while use of the piflufolastat F 18 agent revealed "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 the cohort, information that could alter the approach to therapy, said FDA.

"Conventional imaging has significant limitations in detecting prostate cancer, both in initial staging and when the cancer has recurred or spread after initial primary treatment," added Morris, an investigator on the CONDOR and OSPREY trials. "Specifically, standard imaging poorly detects the early spread to distant organs, such as the lymph nodes, bones, and other organs."

The two trials showed that the agent was well tolerated, with adverse events such as headache, dysgeusia, and fatigue, reported in ≤2% of patients.

In December 2020, the FDA approved gallium (Ga) 68 PSMA-11, the first PET imaging agent that targets PSMA, for use at the University of California Los Angeles and University of California San Francisco.

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    Mike Bassett is a staff writer focusing on oncology and hematology. He is based in Massachusetts.