FDA may disapprove Enzon Pharmaceuticals (ENZN)’s PDUFA

On Friday August 13th, Sesen Bio (SESN) came out with a press release stating that the FDA has disapproved their PDUFA for Biologics License Application for Vicineum™.

“The FDA has determined that it cannot approve the BLA for Vicineum in its present form and has provided recommendations specific to additional clinical/statistical data and analyses in addition to Chemistry, Manufacturing and Controls (CMC) issues pertaining to a recent pre-approval inspection and product quality.”

According to ENZN’s filing:

We have a marketing agreement with Micromet AG, now part of Amgen, Inc. (the “Micromet Agreement”), pursuant to which we may be entitled to a share of certain milestone and royalty payments if Vicineum, a drug being developed by Sesen,,is approved for the treatment of non-muscle invasive bladder cancer. In a press release dated February 16, 2023, Sesen announced that the U.S. Food and Drug Administration (the “FDA”) has accepted for filing Sesen’s Biologic License Application (“BLA”) for Vicineum. The FDA further granted Priority Review, with a target Prescription Drug User Fee Act (“PDUFA”) date for a decision on the BLA of August 18, 2023. Due to the challenges associated with developing and obtaining approval for drug products, and the lack of our involvement in the development and approval process, there is substantial uncertainty as to whether we will receive any milestone or royalty payments under the Micromet Agreement. We will not recognize revenue until all revenue recognition requirements are met.

The FDA may disapprove ENZN’s PDUFA while also making them not susceptible to the payments from milestone or royalties that were under the agreement.