The Food and Drug Administration (FDA) has approved Pylarify® (piflufolastat F 18) injection, a radioactive diagnostic agent, for positron emission tomography (PET) of prostate-specific membrane antigen (PSMA) positive lesions in men with prostate cancer. 

Pylarify is a fluorinated small molecule PSMA-targeted PET imaging agent indicated for men with prostate cancer with suspected metastasis who are candidates for initial definitive therapy. It is also indicated for men with prostate cancer with suspected recurrence based on elevated serum prostate-specific antigen (PSA) levels. The approval was based on data from the phase 2/3 OSPREY ( Identifier: NCT02981368) and phase 3 CONDOR ( Identifier: NCT03739684) trials that evaluated the diagnostic performance and safety of Pylarify injection. 

The OSPREY trial included 268 men with biopsy-proven prostate cancer who were candidates for surgical removal of the prostate gland and pelvic lymph nodes and were considered at higher risk for metastasis. Results showed that Pylarify PET imaging demonstrated improvement in specificity and positive predictive value compared with conventional imaging among patients who proceeded to surgery.

The CONDOR trial included 208 men with biochemical evidence of recurrent prostate cancer after initial prostate surgery or other definitive therapy. Prior to receiving Pylarify PET/CT scan, all patients had baseline conventional imaging evaluation that was negative or equivocal for prostate cancer. Findings demonstrated that Pylarify PET detected at least 1 positive lesion in at least 1 body region in 60% of these patients, including in patients with low PSA values.

As for safety, the most common reported adverse reactions were headache, dysgeusia, and fatigue. The use of Pylarify is associated with a risk of image misinterpretation, hypersensitivity reactions, and radiation risks.

Pylarify is supplied as a 50mL multiple-dose glass vial containing 37 MBq/mL to 2960 MBq/mL (1 mCi/mL to 80 mCi/mL) of piflufolastat F 18. The product will be available immediately to imaging centers in parts of the mid-Atlantic and southern regions and is expected to be available across the US by the end of 2021.


  1. Lantheus receives U.S. FDA approval of Pylarify® (piflufolastat F 18) injection, the first and only commercially available PSMA PET imaging agent for prostate cancer. [press release]. North Billerica, MA: Lantheus Holdings, Inc.; May 27, 2021. 
  2. FDA approves second PSMA-targeted PET imaging drug for men with prostate cancer. Silver Spring, MD: US Food and Drug Administration; May 27, 2021.
  3. Pylarify [package insert]. Billerica, MA: Progenics Pharmaceuticals, Inc.; 2021.